diff --git a/packages/localize/src/tools/src/translate/translation_files/translation_parsers/xliff1_translation_parser.ts b/packages/localize/src/tools/src/translate/translation_files/translation_parsers/xliff1_translation_parser.ts
index dacc24e935572..2dd951ffe4c09 100644
--- a/packages/localize/src/tools/src/translate/translation_files/translation_parsers/xliff1_translation_parser.ts
+++ b/packages/localize/src/tools/src/translate/translation_files/translation_parsers/xliff1_translation_parser.ts
@@ -140,13 +140,23 @@ class XliffTranslationVisitor extends BaseVisitor {
       return;
     }
 
-    // Error if there is no `<target>` child element
-    const targetMessage = element.children.find(isNamedElement('target'));
+    let targetMessage = element.children.find(isNamedElement('target'));
     if (targetMessage === undefined) {
+      // Warn if there is no `<target>` child element
       addParseDiagnostic(
-          bundle.diagnostics, element.sourceSpan, 'Missing required <target> element',
-          ParseErrorLevel.ERROR);
-      return;
+          bundle.diagnostics, element.sourceSpan, 'Missing <target> element',
+          ParseErrorLevel.WARNING);
+
+      // Fallback to the `<source>` element if available.
+      targetMessage = element.children.find(isNamedElement('source'));
+      if (targetMessage === undefined) {
+        // Error if there is neither `<target>` nor `<source>`.
+        addParseDiagnostic(
+            bundle.diagnostics, element.sourceSpan,
+            'Missing required element: one of <target> or <source> is required',
+            ParseErrorLevel.ERROR);
+        return;
+      }
     }
 
     const {translation, parseErrors, serializeErrors} = serializeTranslationMessage(targetMessage, {
diff --git a/packages/localize/src/tools/src/translate/translation_files/translation_parsers/xliff2_translation_parser.ts b/packages/localize/src/tools/src/translate/translation_files/translation_parsers/xliff2_translation_parser.ts
index 2f5edf03efa7e..b47d9c1ff8f44 100644
--- a/packages/localize/src/tools/src/translate/translation_files/translation_parsers/xliff2_translation_parser.ts
+++ b/packages/localize/src/tools/src/translate/translation_files/translation_parsers/xliff2_translation_parser.ts
@@ -132,12 +132,23 @@ class Xliff2TranslationVisitor extends BaseVisitor {
       return;
     }
 
-    const targetMessage = element.children.find(isNamedElement('target'));
+    let targetMessage = element.children.find(isNamedElement('target'));
     if (targetMessage === undefined) {
+      // Warn if there is no `<target>` child element
       addParseDiagnostic(
-          bundle.diagnostics, element.sourceSpan, 'Missing required <target> element',
-          ParseErrorLevel.ERROR);
-      return;
+          bundle.diagnostics, element.sourceSpan, 'Missing <target> element',
+          ParseErrorLevel.WARNING);
+
+      // Fallback to the `<source>` element if available.
+      targetMessage = element.children.find(isNamedElement('source'));
+      if (targetMessage === undefined) {
+        // Error if there is neither `<target>` nor `<source>`.
+        addParseDiagnostic(
+            bundle.diagnostics, element.sourceSpan,
+            'Missing required element: one of <target> or <source> is required',
+            ParseErrorLevel.ERROR);
+        return;
+      }
     }
 
     const {translation, parseErrors, serializeErrors} = serializeTranslationMessage(targetMessage, {
diff --git a/packages/localize/src/tools/test/translate/translation_files/translation_parsers/xliff1_translation_parser_spec.ts b/packages/localize/src/tools/test/translate/translation_files/translation_parsers/xliff1_translation_parser_spec.ts
index 9f475e54e8f69..4eea42a389cb5 100644
--- a/packages/localize/src/tools/test/translate/translation_files/translation_parsers/xliff1_translation_parser_spec.ts
+++ b/packages/localize/src/tools/test/translate/translation_files/translation_parsers/xliff1_translation_parser_spec.ts
@@ -9,754 +9,790 @@ import {ɵcomputeMsgId, ɵmakeParsedTranslation} from '@angular/localize';
 import {ParseAnalysis, ParsedTranslationBundle} from '../../../../src/translate/translation_files/translation_parsers/translation_parser';
 import {Xliff1TranslationParser} from '../../../../src/translate/translation_files/translation_parsers/xliff1_translation_parser';
 
-describe('Xliff1TranslationParser', () => {
-  describe('canParse()', () => {
-    it('should return true only if the file contains an <xliff> element with version="1.2" attribute',
-       () => {
-         const parser = new Xliff1TranslationParser();
-         expect(parser.canParse(
-                    '/some/file.xlf',
-                    '<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">'))
-             .toBeTruthy();
-         expect(parser.canParse(
-                    '/some/file.json',
-                    '<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">'))
-             .toBeTruthy();
-         expect(parser.canParse('/some/file.xliff', '<xliff version="1.2">')).toBeTruthy();
-         expect(parser.canParse('/some/file.json', '<xliff version="1.2">')).toBeTruthy();
-         expect(parser.canParse('/some/file.xlf', '<xliff>')).toBe(false);
-         expect(parser.canParse('/some/file.xlf', '<xliff version="2.0">')).toBe(false);
-         expect(parser.canParse('/some/file.xlf', '')).toBe(false);
-         expect(parser.canParse('/some/file.json', '')).toBe(false);
-       });
-  });
-
-  describe('analyze()', () => {
-    it('should return a success object if the file contains an <xliff> element with version="1.2" attribute',
-       () => {
-         const parser = new Xliff1TranslationParser();
-         expect(parser.analyze('/some/file.xlf', '<xliff version="1.2">'))
-             .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
-         expect(parser.analyze('/some/file.json', '<xliff version="1.2">'))
-             .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
-         expect(parser.analyze('/some/file.xliff', '<xliff version="1.2">'))
-             .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
-         expect(parser.analyze('/some/file.json', '<xliff version="1.2">'))
-             .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
-       });
-
-    it('should return a failure object if the file cannot be parsed as XLIFF 1.2', () => {
-      const parser = new Xliff1TranslationParser();
-      expect(parser.analyze('/some/file.xlf', '<xliff>')).toEqual(jasmine.objectContaining({
-        canParse: false
-      }));
-      expect(parser.analyze('/some/file.xlf', '<xliff version="2.0">'))
-          .toEqual(jasmine.objectContaining({canParse: false}));
-      expect(parser.analyze('/some/file.xlf', '')).toEqual(jasmine.objectContaining({
-        canParse: false
-      }));
-      expect(parser.analyze('/some/file.json', '')).toEqual(jasmine.objectContaining({
-        canParse: false
-      }));
-    });
-
-    it('should return a diagnostics object when the file is not a valid format', () => {
-      let result: ParseAnalysis<any>;
-      const parser = new Xliff1TranslationParser();
-
-      result = parser.analyze('/some/file.xlf', '<moo>');
-      expect(result.diagnostics.messages).toEqual([
-        {type: 'warning', message: 'The XML file does not contain a <xliff> root node.'}
-      ]);
-
-      result = parser.analyze('/some/file.xlf', '<xliff version="2.0">');
-      expect(result.diagnostics.messages).toEqual([{
-        type: 'warning',
-        message:
-            'The <xliff> node does not have the required attribute: version="1.2". ("[WARNING ->]<xliff version="2.0">"): /some/file.xlf@0:0'
-      }]);
-
-      result = parser.analyze('/some/file.xlf', '<xliff version="1.2"></file>');
-      expect(result.diagnostics.messages).toEqual([{
-        type: 'error',
-        message:
-            'Unexpected closing tag "file". It may happen when the tag has already been closed by another tag. For more info see https://www.w3.org/TR/html5/syntax.html#closing-elements-that-have-implied-end-tags ("<xliff version="1.2">[ERROR ->]</file>"): /some/file.xlf@0:21'
-      }]);
-    });
-  });
-
-  for (const withHint of [true, false]) {
-    describe(`parse() [${withHint ? 'with' : 'without'} hint]`, () => {
-      const doParse: (fileName: string, XLIFF: string) => ParsedTranslationBundle =
-          withHint ? (fileName, XLIFF) => {
-            const parser = new Xliff1TranslationParser();
-            const hint = parser.canParse(fileName, XLIFF);
-            if (!hint) {
-              throw new Error('expected XLIFF to be valid');
-            }
-            return parser.parse(fileName, XLIFF, hint);
-          } : (fileName, XLIFF) => {
-            const parser = new Xliff1TranslationParser();
-            return parser.parse(fileName, XLIFF);
-          };
-
-      const expectToFail:
-          (fileName: string, XLIFF: string, errorMatcher: RegExp, diagnosticMessage: string) =>
-              void = withHint ? (fileName, XLIFF, _errorMatcher, diagnosticMessage) => {
-                const result = doParse(fileName, XLIFF);
-                expect(result.diagnostics.messages.length).toEqual(1);
-                expect(result.diagnostics.messages[0].message).toEqual(diagnosticMessage);
-              } : (fileName, XLIFF, errorMatcher, _diagnosticMessage) => {
-                expect(() => doParse(fileName, XLIFF)).toThrowError(errorMatcher);
-              };
-
-      it('should extract the locale from the last `<file>` element to contain a `target-language` attribute',
-         () => {
-           const XLIFF = [
-             `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-             `  <file source-language="en" datatype="plaintext" original="ng2.template">`,
-             `    <body></body>`,
-             `  </file>`,
-             `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-             `    <body></body>`,
-             `  </file>`,
-             `  <file source-language="en" datatype="plaintext" original="ng2.template">`,
-             `    <body></body>`,
-             `  </file>`,
-             `  <file source-language="en" target-language="de" datatype="plaintext" original="ng2.template">`,
-             `    <body></body>`,
-             `  </file>`,
-             `  <file source-language="en" datatype="plaintext" original="ng2.template">`,
-             `    <body></body>`,
-             `  </file>`,
-             `</xliff>`,
-           ].join('\n');
-           const result = doParse('/some/file.xlf', XLIFF);
-           expect(result.locale).toEqual('de');
-         });
-
-      it('should return an undefined locale if there is no locale in the file', () => {
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-        expect(result.locale).toBeUndefined();
-      });
-
-      it('should extract basic messages', () => {
-        /**
-         * Source HTML:
-         *
-         * ```
-         * <div i18n>translatable attribute</div>
-         * ```
-         */
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `      <trans-unit id="1933478729560469763" datatype="html">`,
-          `        <source>translatable attribute</source>`,
-          `        <target>etubirtta elbatalsnart</target>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">file.ts</context>`,
-          `          <context context-type="linenumber">1</context>`,
-          `        </context-group>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-
-        expect(result.translations[ɵcomputeMsgId('translatable attribute')])
-            .toEqual(ɵmakeParsedTranslation(['etubirtta elbatalsnart']));
-      });
-
-      it('should extract translations with simple placeholders', () => {
-        /**
-         * Source HTML:
-         *
-         * ```
-         * <div i18n>translatable element <b>with placeholders</b> {{ interpolation}}</div>
-         * ```
-         */
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `      <trans-unit id="5057824347511785081" datatype="html">`,
-          `        <source>translatable element <x id="START_BOLD_TEXT" ctype="b"/>with placeholders<x id="CLOSE_BOLD_TEXT" ctype="b"/> <x id="INTERPOLATION"/></source>`,
-          `        <target><x id="INTERPOLATION"/> tnemele elbatalsnart <x id="START_BOLD_TEXT" ctype="x-b"/>sredlohecalp htiw<x id="CLOSE_BOLD_TEXT" ctype="x-b"/></target>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">file.ts</context>`,
-          `          <context context-type="linenumber">2</context>`,
-          `        </context-group>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-
-        expect(
-            result.translations[ɵcomputeMsgId(
-                'translatable element {$START_BOLD_TEXT}with placeholders{$LOSE_BOLD_TEXT} {$INTERPOLATION}')])
-            .toEqual(ɵmakeParsedTranslation(
-                ['', ' tnemele elbatalsnart ', 'sredlohecalp htiw', ''],
-                ['INTERPOLATION', 'START_BOLD_TEXT', 'CLOSE_BOLD_TEXT']));
-      });
-
-      it('should extract nested placeholder containers (i.e. nested HTML elements)', () => {
-        /**
-         * Source HTML:
-         *
-         * ```
-         * <div i18n>
-         *   translatable <span>element <b>with placeholders</b></span> {{ interpolation}}
-         * </div>
-         * ```
-         */
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `      <trans-unit id="9051630253697141670" datatype="html">`,
-          `        <source>translatable <x id="START_TAG_SPAN"/>element <x id="START_BOLD_TEXT"/>with placeholders<x id="CLOSE_BOLD_TEXT"/><x id="CLOSE_TAG_SPAN"/> <x id="INTERPOLATION"/></source>`,
-          `        <target><x id="START_TAG_SPAN"/><x id="INTERPOLATION"/> tnemele<x id="CLOSE_TAG_SPAN"/> elbatalsnart <x id="START_BOLD_TEXT"/>sredlohecalp htiw<x id="CLOSE_BOLD_TEXT"/></target>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">file.ts</context>`,
-          `          <context context-type="linenumber">3</context>`,
-          `        </context-group>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-        expect(result.translations[ɵcomputeMsgId(
-                   'translatable {$START_TAG_SPAN}element {$START_BOLD_TEXT}with placeholders' +
-                   '{$CLOSE_BOLD_TEXT}{$CLOSE_TAG_SPAN} {$INTERPOLATION}')])
-            .toEqual(ɵmakeParsedTranslation(
-                ['', '', ' tnemele', ' elbatalsnart ', 'sredlohecalp htiw', ''], [
-                  'START_TAG_SPAN',
-                  'INTERPOLATION',
-                  'CLOSE_TAG_SPAN',
-                  'START_BOLD_TEXT',
-                  'CLOSE_BOLD_TEXT',
-                ]));
-      });
-
-      it('should extract translations with placeholders containing hyphens', () => {
-        /**
-         * Source HTML:
-         *
-         * ```
-         * <div i18n><app-my-component></app-my-component> Welcome</div>
-         * ```
-         */
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `      <trans-unit id="2877147807876214810" datatype="html">`,
-          `        <source><x id="START_TAG_APP-MY-COMPONENT" ctype="x-app-my-component" equiv-text="&lt;app-my-component&gt;"/><x id="CLOSE_TAG_APP-MY-COMPONENT" ctype="x-app-my-component" equiv-text="&lt;/app-my-component&gt;"/> Welcome</source>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">src/app/app.component.html</context>`,
-          `          <context context-type="linenumber">1</context>`,
-          `        </context-group>`,
-          `        <target><x id="START_TAG_APP-MY-COMPONENT" ctype="x-app-my-component" equiv-text="&lt;app-my-component&gt;"/><x id="CLOSE_TAG_APP-MY-COMPONENT" ctype="x-app-my-component" equiv-text="&lt;/app-my-component&gt;"/> Translate</target>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-        const id =
-            ɵcomputeMsgId('{$START_TAG_APP_MY_COMPONENT}{$CLOSE_TAG_APP_MY_COMPONENT} Welcome');
-        expect(result.translations[id]).toEqual(ɵmakeParsedTranslation(['', '', ' Translate'], [
-          'START_TAG_APP_MY_COMPONENT', 'CLOSE_TAG_APP_MY_COMPONENT'
-        ]));
-      });
-
-      it('should extract translations with simple ICU expressions', () => {
-        /**
-         * Source HTML:
-         *
-         * ```
-         * <div i18n>{VAR_PLURAL, plural, =0 {<p>test</p>} }</div>
-         * ```
-         */
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `      <trans-unit id="2874455947211586270" datatype="html">`,
-          `        <source>{VAR_PLURAL, plural, =0 {<x id="START_PARAGRAPH" ctype="x-p"/>test<x id="CLOSE_PARAGRAPH" ctype="x-p"/>} }</source>`,
-          `        <target>{VAR_PLURAL, plural, =0 {<x id="START_PARAGRAPH" ctype="x-p"/>TEST<x id="CLOSE_PARAGRAPH" ctype="x-p"/>} }</target>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-
-        expect(result.translations[ɵcomputeMsgId(
-                   '{VAR_PLURAL, plural, =0 {{START_PARAGRAPH}test{CLOSE_PARAGRAPH}}}')])
-            .toEqual(ɵmakeParsedTranslation(
-                ['{VAR_PLURAL, plural, =0 {{START_PARAGRAPH}TEST{CLOSE_PARAGRAPH}}}'], []));
-      });
-
-      it('should extract translations with duplicate source messages', () => {
-        /**
-         * Source HTML:
-         *
-         * ```
-         * <div i18n>foo</div>
-         * <div i18n="m|d@@i">foo</div>
-         * <div i18=""m|d@@bar>foo</div>
-         * ```
-         */
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `      <trans-unit id="9205907420411818817" datatype="html">`,
-          `        <source>foo</source>`,
-          `        <target>oof</target>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">file.ts</context>`,
-          `          <context context-type="linenumber">3</context>`,
-          `        </context-group>`,
-          `        <note priority="1" from="description">d</note>`,
-          `        <note priority="1" from="meaning">m</note>`,
-          `      </trans-unit>`,
-          `      <trans-unit id="i" datatype="html">`,
-          `        <source>foo</source>`,
-          `        <target>toto</target>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">file.ts</context>`,
-          `          <context context-type="linenumber">4</context>`,
-          `        </context-group>`,
-          `        <note priority="1" from="description">d</note>`,
-          `        <note priority="1" from="meaning">m</note>`,
-          `      </trans-unit>`,
-          `      <trans-unit id="bar" datatype="html">`,
-          `        <source>foo</source>`,
-          `        <target>tata</target>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">file.ts</context>`,
-          `          <context context-type="linenumber">5</context>`,
-          `        </context-group>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-
-        expect(result.translations[ɵcomputeMsgId('foo')]).toEqual(ɵmakeParsedTranslation(['oof']));
-        expect(result.translations['i']).toEqual(ɵmakeParsedTranslation(['toto']));
-        expect(result.translations['bar']).toEqual(ɵmakeParsedTranslation(['tata']));
-      });
-
-      it('should extract translations with only placeholders, which are re-ordered', () => {
-        /**
-         * Source HTML:
-         *
-         * ```
-         * <div i18n><br><img/><img/></div>
-         * ```
-         */
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `      <trans-unit id="7118057989405618448" datatype="html">`,
-          `      <ph id="1" equiv="TAG_IMG" type="image" disp="&lt;img/&gt;"/><ph id="2" equiv="TAG_IMG_1" type="image" disp="&lt;img/&gt;"/>`,
-          `        <source><x id="LINE_BREAK" ctype="lb"/><x id="TAG_IMG" ctype="image"/><x id="TAG_IMG_1" ctype="image"/></source>`,
-          `        <target><x id="TAG_IMG_1" ctype="image"/><x id="TAG_IMG" ctype="image"/><x id="LINE_BREAK" ctype="lb"/></target>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">file.ts</context>`,
-          `          <context context-type="linenumber">6</context>`,
-          `        </context-group>`,
-          `        <note priority="1" from="description">ph names</note>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-
-        expect(result.translations[ɵcomputeMsgId('{$LINE_BREAK}{$TAG_IMG}{$TAG_IMG_1}')])
-            .toEqual(
-                ɵmakeParsedTranslation(['', '', '', ''], ['TAG_IMG_1', 'TAG_IMG', 'LINE_BREAK']));
-      });
-
-      it('should extract translations with empty target', () => {
-        /**
-         * Source HTML:
-         *
-         * ```
-         * <div i18n>hello <span></span></div>
-         * ```
-         */
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `      <trans-unit id="2826198357052921524" datatype="html">`,
-          `        <source>hello <x id="START_TAG_SPAN" ctype="x-span"/><x id="CLOSE_TAG_SPAN" ctype="x-span"/></source>`,
-          `        <target/>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">file.ts</context>`,
-          `          <context context-type="linenumber">6</context>`,
-          `        </context-group>`,
-          `        <note priority="1" from="description">ph names</note>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-
-        expect(result.translations[ɵcomputeMsgId('hello {$START_TAG_SPAN}{$CLOSE_TAG_SPAN}')])
-            .toEqual(ɵmakeParsedTranslation(['']));
-      });
-
-      it('should extract translations with deeply nested ICUs', () => {
-        /**
-         * Source HTML:
-         *
-         * ```
-         * Test: { count, plural, =0 { { sex, select, other {<p>deeply nested</p>}} } =other {a
-         * lot}}
-         * ```
-         *
-         * Note that the message gets split into two translation units:
-         *  * The first one contains the outer message with an `ICU` placeholder
-         *  * The second one is the ICU expansion itself
-         *
-         * Note that special markers `VAR_PLURAL` and `VAR_SELECT` are added, which are then
-         * replaced by IVY at runtime with the actual values being rendered by the ICU expansion.
-         */
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `      <trans-unit id="980940425376233536" datatype="html">`,
-          `        <source>Test: <x id="ICU" equiv-text="{ count, plural, =0 {...} =other {...}}"/></source>`,
-          `        <target>Le test: <x id="ICU" equiv-text="{ count, plural, =0 {...} =other {...}}"/></target>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">file.ts</context>`,
-          `          <context context-type="linenumber">11</context>`,
-          `        </context-group>`,
-          `      </trans-unit>`,
-          `      <trans-unit id="5207293143089349404" datatype="html">`,
-          `        <source>{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {<x id="START_PARAGRAPH" ctype="x-p"/>deeply nested<x id="CLOSE_PARAGRAPH" ctype="x-p"/>}}} =other {a lot}}</source>`,
-          `        <target>{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {<x id="START_PARAGRAPH" ctype="x-p"/>profondément imbriqué<x id="CLOSE_PARAGRAPH" ctype="x-p"/>}}} =other {beaucoup}}</target>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-
-        expect(result.translations[ɵcomputeMsgId('Test: {$ICU}')])
-            .toEqual(ɵmakeParsedTranslation(['Le test: ', ''], ['ICU']));
-
-        expect(
-            result.translations[ɵcomputeMsgId(
-                '{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {{START_PARAGRAPH}deeply nested{CLOSE_PARAGRAPH}}}} =other {beaucoup}}')])
-            .toEqual(ɵmakeParsedTranslation([
-              '{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {{START_PARAGRAPH}profondément imbriqué{CLOSE_PARAGRAPH}}}} =other {beaucoup}}'
-            ]));
-      });
-
-      it('should extract translations containing multiple lines', () => {
-        /**
-         * Source HTML:
-         *
-         * ```
-         * <div i18n>multi
-         * lines</div>
-         * ```
-         */
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `      <trans-unit id="2340165783990709777" datatype="html">`,
-          `        <source>multi\nlines</source>`,
-          `        <target>multi\nlignes</target>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">file.ts</context>`,
-          `          <context context-type="linenumber">12</context>`,
-          `        </context-group>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-
-        expect(result.translations[ɵcomputeMsgId('multi\nlines')])
-            .toEqual(ɵmakeParsedTranslation(['multi\nlignes']));
-      });
-
-      it('should extract translations with <mrk> elements', () => {
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `      <trans-unit id="mrk-test">`,
-          `        <source>First sentence.</source>`,
-          `        <seg-source>`,
-          `          <invalid-tag>Should not be parsed</invalid-tag>`,
-          `        </seg-source>`,
-          `        <target>Translated <mrk mtype="seg" mid="1">first sentence</mrk>.</target>`,
-          `      </trans-unit>`,
-          `      <trans-unit id="mrk-test2">`,
-          `        <source>First sentence. Second sentence.</source>`,
-          `        <seg-source>`,
-          `          <invalid-tag>Should not be parsed</invalid-tag>`,
-          `        </seg-source>`,
-          `        <target>Translated <mrk mtype="seg" mid="1"><mrk mtype="seg" mid="2">first</mrk> sentence</mrk>.</target>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-
-        expect(result.translations['mrk-test'])
-            .toEqual(ɵmakeParsedTranslation(['Translated first sentence.']));
-
-        expect(result.translations['mrk-test2'])
-            .toEqual(ɵmakeParsedTranslation(['Translated first sentence.']));
-      });
-
-      it('should ignore alt-trans targets', () => {
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-          `    <body>`,
-          `      <trans-unit datatype="html" approved="no" id="registration.submit">`,
-          `        <source>Continue</source>`,
-          `        <target state="translated" xml:lang="de">Weiter</target>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">src/app/auth/registration-form/registration-form.component.html</context>`,
-          `          <context context-type="linenumber">69</context>`,
-          `        </context-group>`,
-          `        <?sid 1110954287-0?>`,
-          `        <alt-trans origin="autoFuzzy" tool="Swordfish" match-quality="71" ts="63">`,
-          `          <source xml:lang="en">Content</source>`,
-          `          <target state="translated" xml:lang="de">Content</target>`,
-          `        </alt-trans>`,
-          `    </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-
-        const result = doParse('/some/file.xlf', XLIFF);
-        expect(result.translations['registration.submit'])
-            .toEqual(ɵmakeParsedTranslation(['Weiter']));
+describe(
+    'Xliff1TranslationParser', () => {
+      describe('canParse()', () => {
+        it('should return true only if the file contains an <xliff> element with version="1.2" attribute',
+           () => {
+             const parser = new Xliff1TranslationParser();
+             expect(parser.canParse(
+                        '/some/file.xlf',
+                        '<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">'))
+                 .toBeTruthy();
+             expect(parser.canParse(
+                        '/some/file.json',
+                        '<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">'))
+                 .toBeTruthy();
+             expect(parser.canParse('/some/file.xliff', '<xliff version="1.2">')).toBeTruthy();
+             expect(parser.canParse('/some/file.json', '<xliff version="1.2">')).toBeTruthy();
+             expect(parser.canParse('/some/file.xlf', '<xliff>')).toBe(false);
+             expect(parser.canParse('/some/file.xlf', '<xliff version="2.0">')).toBe(false);
+             expect(parser.canParse('/some/file.xlf', '')).toBe(false);
+             expect(parser.canParse('/some/file.json', '')).toBe(false);
+           });
       });
 
-      it('should merge messages from each `<file>` element', () => {
-        /**
-         * Source HTML:
-         *
-         * ```
-         * <div i18n>translatable attribute</div>
-         * ```
-
-         * ```
-         * <div i18n>translatable element <b>with placeholders</b> {{ interpolation}}</div>
-         * ```
-         */
-        const XLIFF = [
-          `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="file-1">`,
-          `    <body>`,
-          `      <trans-unit id="1933478729560469763" datatype="html">`,
-          `        <source>translatable attribute</source>`,
-          `        <target>etubirtta elbatalsnart</target>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">file.ts</context>`,
-          `          <context context-type="linenumber">1</context>`,
-          `        </context-group>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `  <file source-language="en" target-language="fr" datatype="plaintext" original="file-2">`,
-          `    <body>`,
-          `      <trans-unit id="5057824347511785081" datatype="html">`,
-          `        <source>translatable element <x id="START_BOLD_TEXT" ctype="b"/>with placeholders<x id="CLOSE_BOLD_TEXT" ctype="b"/> <x id="INTERPOLATION"/></source>`,
-          `        <target><x id="INTERPOLATION"/> tnemele elbatalsnart <x id="START_BOLD_TEXT" ctype="x-b"/>sredlohecalp htiw<x id="CLOSE_BOLD_TEXT" ctype="x-b"/></target>`,
-          `        <context-group purpose="location">`,
-          `          <context context-type="sourcefile">file.ts</context>`,
-          `          <context context-type="linenumber">2</context>`,
-          `        </context-group>`,
-          `      </trans-unit>`,
-          `    </body>`,
-          `  </file>`,
-          `</xliff>`,
-        ].join('\n');
-        const result = doParse('/some/file.xlf', XLIFF);
-        expect(result.translations[ɵcomputeMsgId('translatable attribute')])
-            .toEqual(ɵmakeParsedTranslation(['etubirtta elbatalsnart']));
-        expect(
-            result.translations[ɵcomputeMsgId(
-                'translatable element {$START_BOLD_TEXT}with placeholders{$LOSE_BOLD_TEXT} {$INTERPOLATION}')])
-            .toEqual(ɵmakeParsedTranslation(
-                ['', ' tnemele elbatalsnart ', 'sredlohecalp htiw', ''],
-                ['INTERPOLATION', 'START_BOLD_TEXT', 'CLOSE_BOLD_TEXT']));
-      });
-
-      describe('[structure errors]', () => {
-        it('should fail when a trans-unit has no translation', () => {
-          const XLIFF = [
-            `<?xml version="1.0" encoding="UTF-8" ?>`,
-            `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-            `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-            `    <body>`,
-            `      <trans-unit id="missingtarget">`,
-            `        <source/>`,
-            `      </trans-unit>`,
-            `    </body>`,
-            `  </file>`,
-            `</xliff>`,
-          ].join('\n');
-
-          expectToFail('/some/file.xlf', XLIFF, /Missing required <target> element/, [
-            `Missing required <target> element ("e-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-            `    <body>`,
-            `      [ERROR ->]<trans-unit id="missingtarget">`,
-            `        <source/>`,
-            `      </trans-unit>`,
-            `"): /some/file.xlf@4:6`,
-          ].join('\n'));
-        });
-
-
-        it('should fail when a trans-unit has no id attribute', () => {
-          const XLIFF = [
-            `<?xml version="1.0" encoding="UTF-8" ?>`,
-            `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-            `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-            `    <body>`,
-            `      <trans-unit datatype="html">`,
-            `        <source/>`,
-            `        <target/>`,
-            `      </trans-unit>`,
-            `    </body>`,
-            `  </file>`,
-            `</xliff>`,
-          ].join('\n');
-
-          expectToFail('/some/file.xlf', XLIFF, /Missing required "id" attribute/, [
-            `Missing required "id" attribute on <trans-unit> element. ("e-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-            `    <body>`,
-            `      [ERROR ->]<trans-unit datatype="html">`,
-            `        <source/>`,
-            `        <target/>`,
-            `"): /some/file.xlf@4:6`,
-          ].join('\n'));
+      describe('analyze()', () => {
+        it('should return a success object if the file contains an <xliff> element with version="1.2" attribute',
+           () => {
+             const parser = new Xliff1TranslationParser();
+             expect(parser.analyze('/some/file.xlf', '<xliff version="1.2">'))
+                 .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
+             expect(parser.analyze('/some/file.json', '<xliff version="1.2">'))
+                 .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
+             expect(parser.analyze('/some/file.xliff', '<xliff version="1.2">'))
+                 .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
+             expect(parser.analyze('/some/file.json', '<xliff version="1.2">'))
+                 .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
+           });
+
+        it('should return a failure object if the file cannot be parsed as XLIFF 1.2', () => {
+          const parser = new Xliff1TranslationParser();
+          expect(parser.analyze('/some/file.xlf', '<xliff>')).toEqual(jasmine.objectContaining({
+            canParse: false
+          }));
+          expect(parser.analyze('/some/file.xlf', '<xliff version="2.0">'))
+              .toEqual(jasmine.objectContaining({canParse: false}));
+          expect(parser.analyze('/some/file.xlf', '')).toEqual(jasmine.objectContaining({
+            canParse: false
+          }));
+          expect(parser.analyze('/some/file.json', '')).toEqual(jasmine.objectContaining({
+            canParse: false
+          }));
         });
 
-        it('should fail on duplicate trans-unit id', () => {
-          const XLIFF = [
-            `<?xml version="1.0" encoding="UTF-8" ?>`,
-            `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-            `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-            `    <body>`,
-            `      <trans-unit id="deadbeef">`,
-            `        <source/>`,
-            `        <target/>`,
-            `      </trans-unit>`,
-            `      <trans-unit id="deadbeef">`,
-            `        <source/>`,
-            `        <target/>`,
-            `      </trans-unit>`,
-            `    </body>`,
-            `  </file>`,
-            `</xliff>`,
-          ].join('\n');
-
-          expectToFail('/some/file.xlf', XLIFF, /Duplicated translations for message "deadbeef"/, [
-            `Duplicated translations for message "deadbeef" ("`,
-            `        <target/>`,
-            `      </trans-unit>`,
-            `      [ERROR ->]<trans-unit id="deadbeef">`,
-            `        <source/>`,
-            `        <target/>`,
-            `"): /some/file.xlf@8:6`,
-          ].join('\n'));
+        it('should return a diagnostics object when the file is not a valid format', () => {
+          let result: ParseAnalysis<any>;
+          const parser = new Xliff1TranslationParser();
+
+          result = parser.analyze('/some/file.xlf', '<moo>');
+          expect(result.diagnostics.messages).toEqual([
+            {type: 'warning', message: 'The XML file does not contain a <xliff> root node.'}
+          ]);
+
+          result = parser.analyze('/some/file.xlf', '<xliff version="2.0">');
+          expect(result.diagnostics.messages).toEqual([{
+            type: 'warning',
+            message:
+                'The <xliff> node does not have the required attribute: version="1.2". ("[WARNING ->]<xliff version="2.0">"): /some/file.xlf@0:0'
+          }]);
+
+          result = parser.analyze('/some/file.xlf', '<xliff version="1.2"></file>');
+          expect(result.diagnostics.messages).toEqual([{
+            type: 'error',
+            message:
+                'Unexpected closing tag "file". It may happen when the tag has already been closed by another tag. For more info see https://www.w3.org/TR/html5/syntax.html#closing-elements-that-have-implied-end-tags ("<xliff version="1.2">[ERROR ->]</file>"): /some/file.xlf@0:21'
+          }]);
         });
       });
 
-      describe('[message errors]', () => {
-        it('should fail on unknown message tags', () => {
-          const XLIFF = [
-            `<?xml version="1.0" encoding="UTF-8" ?>`,
-            `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-            `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-            `    <body>`,
-            `      <trans-unit id="deadbeef" datatype="html">`,
-            `        <source/>`,
-            `        <target><b>msg should contain only ph tags</b></target>`,
-            `      </trans-unit>`,
-            `    </body>`,
-            `  </file>`,
-            `</xliff>`,
-          ].join('\n');
-
-          expectToFail('/some/file.xlf', XLIFF, /Invalid element found in message/, [
-            `Error: Invalid element found in message.`,
-            `At /some/file.xlf@6:16:`,
-            `...`,
-            `        <source/>`,
-            `        <target>[ERROR ->]<b>msg should contain only ph tags</b></target>`,
-            `      </trans-unit>`,
-            `...`,
-            ``,
-          ].join('\n'));
-        });
-
-        it('should fail when a placeholder misses an id attribute', () => {
-          const XLIFF = [
-            `<?xml version="1.0" encoding="UTF-8" ?>`,
-            `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
-            `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
-            `    <body>`,
-            `      <trans-unit id="deadbeef" datatype="html">`,
-            `        <source/>`,
-            `        <target><x/></target>`,
-            `      </trans-unit>`,
-            `    </body>`,
-            `  </file>`,
-            `</xliff>`,
-          ].join('\n');
-
-          expectToFail('/some/file.xlf', XLIFF, /required "id" attribute/gi, [
-            `Error: Missing required "id" attribute:`,
-            `At /some/file.xlf@6:16:`,
-            `...`,
-            `        <source/>`,
-            `        <target>[ERROR ->]<x/></target>`,
-            `      </trans-unit>`,
-            `...`,
-            ``,
-          ].join('\n'));
-        });
-      });
+      for (const withHint of [true, false]) {
+        describe(
+            `parse() [${withHint ? 'with' : 'without'} hint]`, () => {
+              const doParse: (fileName: string, XLIFF: string) => ParsedTranslationBundle =
+                  withHint ? (fileName, XLIFF) => {
+                    const parser = new Xliff1TranslationParser();
+                    const hint = parser.canParse(fileName, XLIFF);
+                    if (!hint) {
+                      throw new Error('expected XLIFF to be valid');
+                    }
+                    return parser.parse(fileName, XLIFF, hint);
+                  } : (fileName, XLIFF) => {
+                    const parser = new Xliff1TranslationParser();
+                    return parser.parse(fileName, XLIFF);
+                  };
+
+              const expectToFail: (
+                  fileName: string, XLIFF: string, errorMatcher: RegExp,
+                  diagnosticMessage: string) => void =
+                  withHint ? (fileName, XLIFF, _errorMatcher, diagnosticMessage) => {
+                    const result = doParse(fileName, XLIFF);
+                    expect(result.diagnostics.messages.length).toBeGreaterThan(0);
+                    expect(result.diagnostics.messages.pop()!.message).toEqual(diagnosticMessage);
+                  } : (fileName, XLIFF, errorMatcher, _diagnosticMessage) => {
+                    expect(() => doParse(fileName, XLIFF)).toThrowError(errorMatcher);
+                  };
+
+              it('should extract the locale from the last `<file>` element to contain a `target-language` attribute',
+                 () => {
+                   const XLIFF = [
+                     `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                     `  <file source-language="en" datatype="plaintext" original="ng2.template">`,
+                     `    <body></body>`,
+                     `  </file>`,
+                     `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                     `    <body></body>`,
+                     `  </file>`,
+                     `  <file source-language="en" datatype="plaintext" original="ng2.template">`,
+                     `    <body></body>`,
+                     `  </file>`,
+                     `  <file source-language="en" target-language="de" datatype="plaintext" original="ng2.template">`,
+                     `    <body></body>`,
+                     `  </file>`,
+                     `  <file source-language="en" datatype="plaintext" original="ng2.template">`,
+                     `    <body></body>`,
+                     `  </file>`,
+                     `</xliff>`,
+                   ].join('\n');
+                   const result = doParse('/some/file.xlf', XLIFF);
+                   expect(result.locale).toEqual('de');
+                 });
+
+              it('should return an undefined locale if there is no locale in the file', () => {
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+                expect(result.locale).toBeUndefined();
+              });
+
+              it('should extract basic messages', () => {
+                /**
+                 * Source HTML:
+                 *
+                 * ```
+                 * <div i18n>translatable attribute</div>
+                 * ```
+                 */
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `      <trans-unit id="1933478729560469763" datatype="html">`,
+                  `        <source>translatable attribute</source>`,
+                  `        <target>etubirtta elbatalsnart</target>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">file.ts</context>`,
+                  `          <context context-type="linenumber">1</context>`,
+                  `        </context-group>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+
+                expect(result.translations[ɵcomputeMsgId('translatable attribute')])
+                    .toEqual(ɵmakeParsedTranslation(['etubirtta elbatalsnart']));
+              });
+
+              it('should extract translations with simple placeholders', () => {
+                /**
+                 * Source HTML:
+                 *
+                 * ```
+                 * <div i18n>translatable element <b>with placeholders</b> {{ interpolation}}</div>
+                 * ```
+                 */
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `      <trans-unit id="5057824347511785081" datatype="html">`,
+                  `        <source>translatable element <x id="START_BOLD_TEXT" ctype="b"/>with placeholders<x id="CLOSE_BOLD_TEXT" ctype="b"/> <x id="INTERPOLATION"/></source>`,
+                  `        <target><x id="INTERPOLATION"/> tnemele elbatalsnart <x id="START_BOLD_TEXT" ctype="x-b"/>sredlohecalp htiw<x id="CLOSE_BOLD_TEXT" ctype="x-b"/></target>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">file.ts</context>`,
+                  `          <context context-type="linenumber">2</context>`,
+                  `        </context-group>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+
+                expect(
+                    result.translations[ɵcomputeMsgId(
+                        'translatable element {$START_BOLD_TEXT}with placeholders{$LOSE_BOLD_TEXT} {$INTERPOLATION}')])
+                    .toEqual(ɵmakeParsedTranslation(
+                        ['', ' tnemele elbatalsnart ', 'sredlohecalp htiw', ''],
+                        ['INTERPOLATION', 'START_BOLD_TEXT', 'CLOSE_BOLD_TEXT']));
+              });
+
+              it('should extract nested placeholder containers (i.e. nested HTML elements)', () => {
+                /**
+                 * Source HTML:
+                 *
+                 * ```
+                 * <div i18n>
+                 *   translatable <span>element <b>with placeholders</b></span> {{ interpolation}}
+                 * </div>
+                 * ```
+                 */
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `      <trans-unit id="9051630253697141670" datatype="html">`,
+                  `        <source>translatable <x id="START_TAG_SPAN"/>element <x id="START_BOLD_TEXT"/>with placeholders<x id="CLOSE_BOLD_TEXT"/><x id="CLOSE_TAG_SPAN"/> <x id="INTERPOLATION"/></source>`,
+                  `        <target><x id="START_TAG_SPAN"/><x id="INTERPOLATION"/> tnemele<x id="CLOSE_TAG_SPAN"/> elbatalsnart <x id="START_BOLD_TEXT"/>sredlohecalp htiw<x id="CLOSE_BOLD_TEXT"/></target>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">file.ts</context>`,
+                  `          <context context-type="linenumber">3</context>`,
+                  `        </context-group>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+                expect(
+                    result.translations[ɵcomputeMsgId(
+                        'translatable {$START_TAG_SPAN}element {$START_BOLD_TEXT}with placeholders' +
+                        '{$CLOSE_BOLD_TEXT}{$CLOSE_TAG_SPAN} {$INTERPOLATION}')])
+                    .toEqual(ɵmakeParsedTranslation(
+                        ['', '', ' tnemele', ' elbatalsnart ', 'sredlohecalp htiw', ''], [
+                          'START_TAG_SPAN',
+                          'INTERPOLATION',
+                          'CLOSE_TAG_SPAN',
+                          'START_BOLD_TEXT',
+                          'CLOSE_BOLD_TEXT',
+                        ]));
+              });
+
+              it('should extract translations with placeholders containing hyphens', () => {
+                /**
+                 * Source HTML:
+                 *
+                 * ```
+                 * <div i18n><app-my-component></app-my-component> Welcome</div>
+                 * ```
+                 */
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `      <trans-unit id="2877147807876214810" datatype="html">`,
+                  `        <source><x id="START_TAG_APP-MY-COMPONENT" ctype="x-app-my-component" equiv-text="&lt;app-my-component&gt;"/><x id="CLOSE_TAG_APP-MY-COMPONENT" ctype="x-app-my-component" equiv-text="&lt;/app-my-component&gt;"/> Welcome</source>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">src/app/app.component.html</context>`,
+                  `          <context context-type="linenumber">1</context>`,
+                  `        </context-group>`,
+                  `        <target><x id="START_TAG_APP-MY-COMPONENT" ctype="x-app-my-component" equiv-text="&lt;app-my-component&gt;"/><x id="CLOSE_TAG_APP-MY-COMPONENT" ctype="x-app-my-component" equiv-text="&lt;/app-my-component&gt;"/> Translate</target>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+                const id = ɵcomputeMsgId(
+                    '{$START_TAG_APP_MY_COMPONENT}{$CLOSE_TAG_APP_MY_COMPONENT} Welcome');
+                expect(result.translations[id])
+                    .toEqual(ɵmakeParsedTranslation(
+                        ['', '', ' Translate'],
+                        ['START_TAG_APP_MY_COMPONENT', 'CLOSE_TAG_APP_MY_COMPONENT']));
+              });
+
+              it('should extract translations with simple ICU expressions', () => {
+                /**
+                 * Source HTML:
+                 *
+                 * ```
+                 * <div i18n>{VAR_PLURAL, plural, =0 {<p>test</p>} }</div>
+                 * ```
+                 */
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `      <trans-unit id="2874455947211586270" datatype="html">`,
+                  `        <source>{VAR_PLURAL, plural, =0 {<x id="START_PARAGRAPH" ctype="x-p"/>test<x id="CLOSE_PARAGRAPH" ctype="x-p"/>} }</source>`,
+                  `        <target>{VAR_PLURAL, plural, =0 {<x id="START_PARAGRAPH" ctype="x-p"/>TEST<x id="CLOSE_PARAGRAPH" ctype="x-p"/>} }</target>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+
+                expect(result.translations[ɵcomputeMsgId(
+                           '{VAR_PLURAL, plural, =0 {{START_PARAGRAPH}test{CLOSE_PARAGRAPH}}}')])
+                    .toEqual(ɵmakeParsedTranslation(
+                        ['{VAR_PLURAL, plural, =0 {{START_PARAGRAPH}TEST{CLOSE_PARAGRAPH}}}'], []));
+              });
+
+              it('should extract translations with duplicate source messages', () => {
+                /**
+                 * Source HTML:
+                 *
+                 * ```
+                 * <div i18n>foo</div>
+                 * <div i18n="m|d@@i">foo</div>
+                 * <div i18=""m|d@@bar>foo</div>
+                 * ```
+                 */
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `      <trans-unit id="9205907420411818817" datatype="html">`,
+                  `        <source>foo</source>`,
+                  `        <target>oof</target>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">file.ts</context>`,
+                  `          <context context-type="linenumber">3</context>`,
+                  `        </context-group>`,
+                  `        <note priority="1" from="description">d</note>`,
+                  `        <note priority="1" from="meaning">m</note>`,
+                  `      </trans-unit>`,
+                  `      <trans-unit id="i" datatype="html">`,
+                  `        <source>foo</source>`,
+                  `        <target>toto</target>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">file.ts</context>`,
+                  `          <context context-type="linenumber">4</context>`,
+                  `        </context-group>`,
+                  `        <note priority="1" from="description">d</note>`,
+                  `        <note priority="1" from="meaning">m</note>`,
+                  `      </trans-unit>`,
+                  `      <trans-unit id="bar" datatype="html">`,
+                  `        <source>foo</source>`,
+                  `        <target>tata</target>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">file.ts</context>`,
+                  `          <context context-type="linenumber">5</context>`,
+                  `        </context-group>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+
+                expect(result.translations[ɵcomputeMsgId('foo')])
+                    .toEqual(ɵmakeParsedTranslation(['oof']));
+                expect(result.translations['i']).toEqual(ɵmakeParsedTranslation(['toto']));
+                expect(result.translations['bar']).toEqual(ɵmakeParsedTranslation(['tata']));
+              });
+
+              it('should extract translations with only placeholders, which are re-ordered', () => {
+                /**
+                 * Source HTML:
+                 *
+                 * ```
+                 * <div i18n><br><img/><img/></div>
+                 * ```
+                 */
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `      <trans-unit id="7118057989405618448" datatype="html">`,
+                  `      <ph id="1" equiv="TAG_IMG" type="image" disp="&lt;img/&gt;"/><ph id="2" equiv="TAG_IMG_1" type="image" disp="&lt;img/&gt;"/>`,
+                  `        <source><x id="LINE_BREAK" ctype="lb"/><x id="TAG_IMG" ctype="image"/><x id="TAG_IMG_1" ctype="image"/></source>`,
+                  `        <target><x id="TAG_IMG_1" ctype="image"/><x id="TAG_IMG" ctype="image"/><x id="LINE_BREAK" ctype="lb"/></target>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">file.ts</context>`,
+                  `          <context context-type="linenumber">6</context>`,
+                  `        </context-group>`,
+                  `        <note priority="1" from="description">ph names</note>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+
+                expect(result.translations[ɵcomputeMsgId('{$LINE_BREAK}{$TAG_IMG}{$TAG_IMG_1}')])
+                    .toEqual(ɵmakeParsedTranslation(
+                        ['', '', '', ''], ['TAG_IMG_1', 'TAG_IMG', 'LINE_BREAK']));
+              });
+
+              it('should extract translations with empty target', () => {
+                /**
+                 * Source HTML:
+                 *
+                 * ```
+                 * <div i18n>hello <span></span></div>
+                 * ```
+                 */
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `      <trans-unit id="2826198357052921524" datatype="html">`,
+                  `        <source>hello <x id="START_TAG_SPAN" ctype="x-span"/><x id="CLOSE_TAG_SPAN" ctype="x-span"/></source>`,
+                  `        <target/>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">file.ts</context>`,
+                  `          <context context-type="linenumber">6</context>`,
+                  `        </context-group>`,
+                  `        <note priority="1" from="description">ph names</note>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+
+                expect(
+                    result.translations[ɵcomputeMsgId('hello {$START_TAG_SPAN}{$CLOSE_TAG_SPAN}')])
+                    .toEqual(ɵmakeParsedTranslation(['']));
+              });
+
+              it('should extract translations with deeply nested ICUs', () => {
+                /**
+                 * Source HTML:
+                 *
+                 * ```
+                 * Test: { count, plural, =0 { { sex, select, other {<p>deeply nested</p>}} }
+                 * =other {a lot}}
+                 * ```
+                 *
+                 * Note that the message gets split into two translation units:
+                 *  * The first one contains the outer message with an `ICU` placeholder
+                 *  * The second one is the ICU expansion itself
+                 *
+                 * Note that special markers `VAR_PLURAL` and `VAR_SELECT` are added, which are then
+                 * replaced by IVY at runtime with the actual values being rendered by the ICU
+                 * expansion.
+                 */
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `      <trans-unit id="980940425376233536" datatype="html">`,
+                  `        <source>Test: <x id="ICU" equiv-text="{ count, plural, =0 {...} =other {...}}"/></source>`,
+                  `        <target>Le test: <x id="ICU" equiv-text="{ count, plural, =0 {...} =other {...}}"/></target>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">file.ts</context>`,
+                  `          <context context-type="linenumber">11</context>`,
+                  `        </context-group>`,
+                  `      </trans-unit>`,
+                  `      <trans-unit id="5207293143089349404" datatype="html">`,
+                  `        <source>{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {<x id="START_PARAGRAPH" ctype="x-p"/>deeply nested<x id="CLOSE_PARAGRAPH" ctype="x-p"/>}}} =other {a lot}}</source>`,
+                  `        <target>{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {<x id="START_PARAGRAPH" ctype="x-p"/>profondément imbriqué<x id="CLOSE_PARAGRAPH" ctype="x-p"/>}}} =other {beaucoup}}</target>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+
+                expect(result.translations[ɵcomputeMsgId('Test: {$ICU}')])
+                    .toEqual(ɵmakeParsedTranslation(['Le test: ', ''], ['ICU']));
+
+                expect(
+                    result.translations[ɵcomputeMsgId(
+                        '{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {{START_PARAGRAPH}deeply nested{CLOSE_PARAGRAPH}}}} =other {beaucoup}}')])
+                    .toEqual(ɵmakeParsedTranslation([
+                      '{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {{START_PARAGRAPH}profondément imbriqué{CLOSE_PARAGRAPH}}}} =other {beaucoup}}'
+                    ]));
+              });
+
+              it('should extract translations containing multiple lines', () => {
+                /**
+                 * Source HTML:
+                 *
+                 * ```
+                 * <div i18n>multi
+                 * lines</div>
+                 * ```
+                 */
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `      <trans-unit id="2340165783990709777" datatype="html">`,
+                  `        <source>multi\nlines</source>`,
+                  `        <target>multi\nlignes</target>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">file.ts</context>`,
+                  `          <context context-type="linenumber">12</context>`,
+                  `        </context-group>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+
+                expect(result.translations[ɵcomputeMsgId('multi\nlines')])
+                    .toEqual(ɵmakeParsedTranslation(['multi\nlignes']));
+              });
+
+              it('should extract translations with <mrk> elements', () => {
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `      <trans-unit id="mrk-test">`,
+                  `        <source>First sentence.</source>`,
+                  `        <seg-source>`,
+                  `          <invalid-tag>Should not be parsed</invalid-tag>`,
+                  `        </seg-source>`,
+                  `        <target>Translated <mrk mtype="seg" mid="1">first sentence</mrk>.</target>`,
+                  `      </trans-unit>`,
+                  `      <trans-unit id="mrk-test2">`,
+                  `        <source>First sentence. Second sentence.</source>`,
+                  `        <seg-source>`,
+                  `          <invalid-tag>Should not be parsed</invalid-tag>`,
+                  `        </seg-source>`,
+                  `        <target>Translated <mrk mtype="seg" mid="1"><mrk mtype="seg" mid="2">first</mrk> sentence</mrk>.</target>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+
+                expect(result.translations['mrk-test'])
+                    .toEqual(ɵmakeParsedTranslation(['Translated first sentence.']));
+
+                expect(result.translations['mrk-test2'])
+                    .toEqual(ɵmakeParsedTranslation(['Translated first sentence.']));
+              });
+
+              it('should ignore alt-trans targets', () => {
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                  `    <body>`,
+                  `      <trans-unit datatype="html" approved="no" id="registration.submit">`,
+                  `        <source>Continue</source>`,
+                  `        <target state="translated" xml:lang="de">Weiter</target>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">src/app/auth/registration-form/registration-form.component.html</context>`,
+                  `          <context context-type="linenumber">69</context>`,
+                  `        </context-group>`,
+                  `        <?sid 1110954287-0?>`,
+                  `        <alt-trans origin="autoFuzzy" tool="Swordfish" match-quality="71" ts="63">`,
+                  `          <source xml:lang="en">Content</source>`,
+                  `          <target state="translated" xml:lang="de">Content</target>`,
+                  `        </alt-trans>`,
+                  `    </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+
+                const result = doParse('/some/file.xlf', XLIFF);
+                expect(result.translations['registration.submit'])
+                    .toEqual(ɵmakeParsedTranslation(['Weiter']));
+              });
+
+              it('should merge messages from each `<file>` element', () => {
+                /**
+                 * Source HTML:
+                 *
+                 * ```
+                 * <div i18n>translatable attribute</div>
+                 * ```
+
+                 * ```
+                 * <div i18n>translatable element <b>with placeholders</b> {{ interpolation}}</div>
+                 * ```
+                 */
+                const XLIFF = [
+                  `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="file-1">`,
+                  `    <body>`,
+                  `      <trans-unit id="1933478729560469763" datatype="html">`,
+                  `        <source>translatable attribute</source>`,
+                  `        <target>etubirtta elbatalsnart</target>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">file.ts</context>`,
+                  `          <context context-type="linenumber">1</context>`,
+                  `        </context-group>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `  <file source-language="en" target-language="fr" datatype="plaintext" original="file-2">`,
+                  `    <body>`,
+                  `      <trans-unit id="5057824347511785081" datatype="html">`,
+                  `        <source>translatable element <x id="START_BOLD_TEXT" ctype="b"/>with placeholders<x id="CLOSE_BOLD_TEXT" ctype="b"/> <x id="INTERPOLATION"/></source>`,
+                  `        <target><x id="INTERPOLATION"/> tnemele elbatalsnart <x id="START_BOLD_TEXT" ctype="x-b"/>sredlohecalp htiw<x id="CLOSE_BOLD_TEXT" ctype="x-b"/></target>`,
+                  `        <context-group purpose="location">`,
+                  `          <context context-type="sourcefile">file.ts</context>`,
+                  `          <context context-type="linenumber">2</context>`,
+                  `        </context-group>`,
+                  `      </trans-unit>`,
+                  `    </body>`,
+                  `  </file>`,
+                  `</xliff>`,
+                ].join('\n');
+                const result = doParse('/some/file.xlf', XLIFF);
+                expect(result.translations[ɵcomputeMsgId('translatable attribute')])
+                    .toEqual(ɵmakeParsedTranslation(['etubirtta elbatalsnart']));
+                expect(
+                    result.translations[ɵcomputeMsgId(
+                        'translatable element {$START_BOLD_TEXT}with placeholders{$LOSE_BOLD_TEXT} {$INTERPOLATION}')])
+                    .toEqual(ɵmakeParsedTranslation(
+                        ['', ' tnemele elbatalsnart ', 'sredlohecalp htiw', ''],
+                        ['INTERPOLATION', 'START_BOLD_TEXT', 'CLOSE_BOLD_TEXT']));
+              });
+
+              describe('[structure errors]', () => {
+                it('should warn when a trans-unit has no translation target but does have a source',
+                   () => {
+                     const XLIFF = [
+                       `<?xml version="1.0" encoding="UTF-8" ?>`,
+                       `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                       `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                       `    <body>`,
+                       `      <trans-unit id="missingtarget">`,
+                       `        <source/>`,
+                       `      </trans-unit>`,
+                       `    </body>`,
+                       `  </file>`,
+                       `</xliff>`,
+                     ].join('\n');
+
+                     const result = doParse('/some/file.xlf', XLIFF);
+                     expect(result.diagnostics.messages.length).toEqual(1);
+                     expect(result.diagnostics.messages[0].message).toEqual([
+                       `Missing <target> element ("e-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                       `    <body>`,
+                       `      [WARNING ->]<trans-unit id="missingtarget">`,
+                       `        <source/>`,
+                       `      </trans-unit>`,
+                       `"): /some/file.xlf@4:6`,
+                     ].join('\n'));
+                   });
+
+                it('should fail when a trans-unit has no translation target nor source', () => {
+                  const XLIFF = [
+                    `<?xml version="1.0" encoding="UTF-8" ?>`,
+                    `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                    `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                    `    <body>`,
+                    `      <trans-unit id="missingtarget">`,
+                    `      </trans-unit>`,
+                    `    </body>`,
+                    `  </file>`,
+                    `</xliff>`,
+                  ].join('\n');
+
+                  expectToFail(
+                      '/some/file.xlf', XLIFF,
+                      /Missing required element: one of <target> or <source> is required/, [
+                        `Missing required element: one of <target> or <source> is required ("e-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                        `    <body>`,
+                        `      [ERROR ->]<trans-unit id="missingtarget">`,
+                        `      </trans-unit>`,
+                        `    </body>`,
+                        `"): /some/file.xlf@4:6`,
+                      ].join('\n'));
+                });
+
+                it('should fail when a trans-unit has no id attribute', () => {
+                  const XLIFF = [
+                    `<?xml version="1.0" encoding="UTF-8" ?>`,
+                    `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                    `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                    `    <body>`,
+                    `      <trans-unit datatype="html">`,
+                    `        <source/>`,
+                    `        <target/>`,
+                    `      </trans-unit>`,
+                    `    </body>`,
+                    `  </file>`,
+                    `</xliff>`,
+                  ].join('\n');
+
+                  expectToFail('/some/file.xlf', XLIFF, /Missing required "id" attribute/, [
+                    `Missing required "id" attribute on <trans-unit> element. ("e-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                    `    <body>`,
+                    `      [ERROR ->]<trans-unit datatype="html">`,
+                    `        <source/>`,
+                    `        <target/>`,
+                    `"): /some/file.xlf@4:6`,
+                  ].join('\n'));
+                });
+
+                it('should fail on duplicate trans-unit id', () => {
+                  const XLIFF = [
+                    `<?xml version="1.0" encoding="UTF-8" ?>`,
+                    `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                    `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                    `    <body>`,
+                    `      <trans-unit id="deadbeef">`,
+                    `        <source/>`,
+                    `        <target/>`,
+                    `      </trans-unit>`,
+                    `      <trans-unit id="deadbeef">`,
+                    `        <source/>`,
+                    `        <target/>`,
+                    `      </trans-unit>`,
+                    `    </body>`,
+                    `  </file>`,
+                    `</xliff>`,
+                  ].join('\n');
+
+                  expectToFail(
+                      '/some/file.xlf', XLIFF, /Duplicated translations for message "deadbeef"/, [
+                        `Duplicated translations for message "deadbeef" ("`,
+                        `        <target/>`,
+                        `      </trans-unit>`,
+                        `      [ERROR ->]<trans-unit id="deadbeef">`,
+                        `        <source/>`,
+                        `        <target/>`,
+                        `"): /some/file.xlf@8:6`,
+                      ].join('\n'));
+                });
+              });
+
+              describe('[message errors]', () => {
+                it('should fail on unknown message tags', () => {
+                  const XLIFF = [
+                    `<?xml version="1.0" encoding="UTF-8" ?>`,
+                    `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                    `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                    `    <body>`,
+                    `      <trans-unit id="deadbeef" datatype="html">`,
+                    `        <source/>`,
+                    `        <target><b>msg should contain only ph tags</b></target>`,
+                    `      </trans-unit>`,
+                    `    </body>`,
+                    `  </file>`,
+                    `</xliff>`,
+                  ].join('\n');
+
+                  expectToFail('/some/file.xlf', XLIFF, /Invalid element found in message/, [
+                    `Error: Invalid element found in message.`,
+                    `At /some/file.xlf@6:16:`,
+                    `...`,
+                    `        <source/>`,
+                    `        <target>[ERROR ->]<b>msg should contain only ph tags</b></target>`,
+                    `      </trans-unit>`,
+                    `...`,
+                    ``,
+                  ].join('\n'));
+                });
+
+                it('should fail when a placeholder misses an id attribute', () => {
+                  const XLIFF = [
+                    `<?xml version="1.0" encoding="UTF-8" ?>`,
+                    `<xliff version="1.2" xmlns="urn:oasis:names:tc:xliff:document:1.2">`,
+                    `  <file source-language="en" target-language="fr" datatype="plaintext" original="ng2.template">`,
+                    `    <body>`,
+                    `      <trans-unit id="deadbeef" datatype="html">`,
+                    `        <source/>`,
+                    `        <target><x/></target>`,
+                    `      </trans-unit>`,
+                    `    </body>`,
+                    `  </file>`,
+                    `</xliff>`,
+                  ].join('\n');
+
+                  expectToFail('/some/file.xlf', XLIFF, /required "id" attribute/gi, [
+                    `Error: Missing required "id" attribute:`,
+                    `At /some/file.xlf@6:16:`,
+                    `...`,
+                    `        <source/>`,
+                    `        <target>[ERROR ->]<x/></target>`,
+                    `      </trans-unit>`,
+                    `...`,
+                    ``,
+                  ].join('\n'));
+                });
+              });
+            });
+      }
     });
-  }
-});
diff --git a/packages/localize/src/tools/test/translate/translation_files/translation_parsers/xliff2_translation_parser_spec.ts b/packages/localize/src/tools/test/translate/translation_files/translation_parsers/xliff2_translation_parser_spec.ts
index d9b412c8bc486..bb9000d09bd89 100644
--- a/packages/localize/src/tools/test/translate/translation_files/translation_parsers/xliff2_translation_parser_spec.ts
+++ b/packages/localize/src/tools/test/translate/translation_files/translation_parsers/xliff2_translation_parser_spec.ts
@@ -9,686 +9,711 @@ import {ɵcomputeMsgId, ɵmakeParsedTranslation} from '@angular/localize';
 import {ParseAnalysis, ParsedTranslationBundle} from '../../../../src/translate/translation_files/translation_parsers/translation_parser';
 import {Xliff2TranslationParser} from '../../../../src/translate/translation_files/translation_parsers/xliff2_translation_parser';
 
-describe(
-    'Xliff2TranslationParser', () => {
-      describe('canParse()', () => {
-        it('should return true if the file contains an <xliff> element with version="2.0" attribute',
-           () => {
-             const parser = new Xliff2TranslationParser();
-             expect(parser.canParse(
-                        '/some/file.xlf',
-                        '<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0">'))
-                 .toBeTruthy();
-             expect(parser.canParse(
-                        '/some/file.json',
-                        '<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0">'))
-                 .toBeTruthy();
-             expect(parser.canParse('/some/file.xliff', '<xliff version="2.0">')).toBeTruthy();
-             expect(parser.canParse('/some/file.json', '<xliff version="2.0">')).toBeTruthy();
-             expect(parser.canParse('/some/file.xlf', '<xliff>')).toBe(false);
-             expect(parser.canParse('/some/file.xlf', '<xliff version="1.2">')).toBe(false);
-             expect(parser.canParse('/some/file.xlf', '')).toBe(false);
-             expect(parser.canParse('/some/file.json', '')).toBe(false);
-           });
-      });
-
-      describe('analyze', () => {
-        it('should return a success object if the file contains an <xliff> element with version="2.0" attribute',
-           () => {
-             const parser = new Xliff2TranslationParser();
-             expect(parser.analyze(
-                        '/some/file.xlf',
-                        '<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0">'))
-                 .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
-             expect(parser.analyze(
-                        '/some/file.json',
-                        '<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0">'))
-                 .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
-             expect(parser.analyze('/some/file.xliff', '<xliff version="2.0">'))
-                 .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
-             expect(parser.analyze('/some/file.json', '<xliff version="2.0">'))
-                 .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
-           });
-
-        it('should return a failure object if the file cannot be parsed as XLIFF 2.0', () => {
-          const parser = new Xliff2TranslationParser();
-          expect(parser.analyze('/some/file.xlf', '<xliff>')).toEqual(jasmine.objectContaining({
-            canParse: false
-          }));
-          expect(parser.analyze('/some/file.xlf', '<xliff version="1.2">'))
-              .toEqual(jasmine.objectContaining({canParse: false}));
-          expect(parser.analyze('/some/file.xlf', '')).toEqual(jasmine.objectContaining({
-            canParse: false
-          }));
-          expect(parser.analyze('/some/file.json', '')).toEqual(jasmine.objectContaining({
-            canParse: false
-          }));
-        });
+describe('Xliff2TranslationParser', () => {
+  describe('canParse()', () => {
+    it('should return true if the file contains an <xliff> element with version="2.0" attribute',
+       () => {
+         const parser = new Xliff2TranslationParser();
+         expect(parser.canParse(
+                    '/some/file.xlf',
+                    '<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0">'))
+             .toBeTruthy();
+         expect(parser.canParse(
+                    '/some/file.json',
+                    '<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0">'))
+             .toBeTruthy();
+         expect(parser.canParse('/some/file.xliff', '<xliff version="2.0">')).toBeTruthy();
+         expect(parser.canParse('/some/file.json', '<xliff version="2.0">')).toBeTruthy();
+         expect(parser.canParse('/some/file.xlf', '<xliff>')).toBe(false);
+         expect(parser.canParse('/some/file.xlf', '<xliff version="1.2">')).toBe(false);
+         expect(parser.canParse('/some/file.xlf', '')).toBe(false);
+         expect(parser.canParse('/some/file.json', '')).toBe(false);
+       });
+  });
+
+  describe('analyze', () => {
+    it('should return a success object if the file contains an <xliff> element with version="2.0" attribute',
+       () => {
+         const parser = new Xliff2TranslationParser();
+         expect(parser.analyze(
+                    '/some/file.xlf',
+                    '<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0">'))
+             .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
+         expect(parser.analyze(
+                    '/some/file.json',
+                    '<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0">'))
+             .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
+         expect(parser.analyze('/some/file.xliff', '<xliff version="2.0">'))
+             .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
+         expect(parser.analyze('/some/file.json', '<xliff version="2.0">'))
+             .toEqual(jasmine.objectContaining({canParse: true, hint: jasmine.any(Object)}));
+       });
+
+    it('should return a failure object if the file cannot be parsed as XLIFF 2.0', () => {
+      const parser = new Xliff2TranslationParser();
+      expect(parser.analyze('/some/file.xlf', '<xliff>')).toEqual(jasmine.objectContaining({
+        canParse: false
+      }));
+      expect(parser.analyze('/some/file.xlf', '<xliff version="1.2">'))
+          .toEqual(jasmine.objectContaining({canParse: false}));
+      expect(parser.analyze('/some/file.xlf', '')).toEqual(jasmine.objectContaining({
+        canParse: false
+      }));
+      expect(parser.analyze('/some/file.json', '')).toEqual(jasmine.objectContaining({
+        canParse: false
+      }));
+    });
 
-        it('should return a diagnostics object when the file is not a valid format', () => {
-          let result: ParseAnalysis<any>;
-          const parser = new Xliff2TranslationParser();
-
-          result = parser.analyze('/some/file.xlf', '<moo>');
-          expect(result.diagnostics.messages).toEqual([
-            {type: 'warning', message: 'The XML file does not contain a <xliff> root node.'}
-          ]);
-
-          result = parser.analyze('/some/file.xlf', '<xliff version="1.2">');
-          expect(result.diagnostics.messages).toEqual([{
-            type: 'warning',
-            message:
-                'The <xliff> node does not have the required attribute: version="2.0". ("[WARNING ->]<xliff version="1.2">"): /some/file.xlf@0:0'
-          }]);
-
-          result = parser.analyze('/some/file.xlf', '<xliff version="2.0"></file>');
-          expect(result.diagnostics.messages).toEqual([{
-            type: 'error',
-            message:
-                'Unexpected closing tag "file". It may happen when the tag has already been closed by another tag. For more info see https://www.w3.org/TR/html5/syntax.html#closing-elements-that-have-implied-end-tags ("<xliff version="2.0">[ERROR ->]</file>"): /some/file.xlf@0:21'
-          }]);
-        });
-      });
-
-      for (const withHint of [true, false]) {
-        describe(
-            `parse() [${withHint ? 'with' : 'without'} hint]`, () => {
-              const doParse: (fileName: string, XLIFF: string) => ParsedTranslationBundle =
-                  withHint ? (fileName, XLIFF) => {
-                    const parser = new Xliff2TranslationParser();
-                    const hint = parser.canParse(fileName, XLIFF);
-                    if (!hint) {
-                      throw new Error('expected XLIFF to be valid');
-                    }
-                    return parser.parse(fileName, XLIFF, hint);
-                  } : (fileName, XLIFF) => {
-                    const parser = new Xliff2TranslationParser();
-                    return parser.parse(fileName, XLIFF);
+    it('should return a diagnostics object when the file is not a valid format', () => {
+      let result: ParseAnalysis<any>;
+      const parser = new Xliff2TranslationParser();
+
+      result = parser.analyze('/some/file.xlf', '<moo>');
+      expect(result.diagnostics.messages).toEqual([
+        {type: 'warning', message: 'The XML file does not contain a <xliff> root node.'}
+      ]);
+
+      result = parser.analyze('/some/file.xlf', '<xliff version="1.2">');
+      expect(result.diagnostics.messages).toEqual([{
+        type: 'warning',
+        message:
+            'The <xliff> node does not have the required attribute: version="2.0". ("[WARNING ->]<xliff version="1.2">"): /some/file.xlf@0:0'
+      }]);
+
+      result = parser.analyze('/some/file.xlf', '<xliff version="2.0"></file>');
+      expect(result.diagnostics.messages).toEqual([{
+        type: 'error',
+        message:
+            'Unexpected closing tag "file". It may happen when the tag has already been closed by another tag. For more info see https://www.w3.org/TR/html5/syntax.html#closing-elements-that-have-implied-end-tags ("<xliff version="2.0">[ERROR ->]</file>"): /some/file.xlf@0:21'
+      }]);
+    });
+  });
+
+  for (const withHint of [true, false]) {
+    describe(
+        `parse() [${withHint ? 'with' : 'without'} hint]`, () => {
+          const doParse: (fileName: string, XLIFF: string) => ParsedTranslationBundle =
+              withHint ? (fileName, XLIFF) => {
+                const parser = new Xliff2TranslationParser();
+                const hint = parser.canParse(fileName, XLIFF);
+                if (!hint) {
+                  throw new Error('expected XLIFF to be valid');
+                }
+                return parser.parse(fileName, XLIFF, hint);
+              } : (fileName, XLIFF) => {
+                const parser = new Xliff2TranslationParser();
+                return parser.parse(fileName, XLIFF);
+              };
+
+          const expectToFail:
+              (fileName: string, XLIFF: string, errorMatcher: RegExp, diagnosticMessage: string) =>
+                  void = withHint ? (fileName, XLIFF, _errorMatcher, diagnosticMessage) => {
+                    const result = doParse(fileName, XLIFF);
+                    expect(result.diagnostics.messages.length).toBeGreaterThan(0);
+                    expect(result.diagnostics.messages.pop()!.message).toEqual(diagnosticMessage);
+                  } : (fileName, XLIFF, errorMatcher, _diagnosticMessage) => {
+                    expect(() => doParse(fileName, XLIFF)).toThrowError(errorMatcher);
                   };
 
-              const expectToFail:
-                  (fileName: string, XLIFF: string, errorMatcher: RegExp,
-                   diagnosticMessage: string) => void =
-                      withHint ? (fileName, XLIFF, _errorMatcher, diagnosticMessage) => {
-                        const result = doParse(fileName, XLIFF);
-                        expect(result.diagnostics.messages.length).toEqual(1);
-                        expect(result.diagnostics.messages[0].message).toEqual(diagnosticMessage);
-                      } : (fileName, XLIFF, errorMatcher, _diagnosticMessage) => {
-                        expect(() => doParse(fileName, XLIFF)).toThrowError(errorMatcher);
-                      };
-
-              it('should extract the locale from the file contents', () => {
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                  `  <file original="ng.template" id="ngi18n">`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(result.locale).toEqual('fr');
-              });
-
-              it('should return undefined locale if there is no locale in the file', () => {
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en">`,
-                  `  <file original="ng.template" id="ngi18n">`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(result.locale).toBeUndefined();
-              });
-
-              it('should extract basic messages', () => {
-                /**
-                 * Source HTML:
-                 *
-                 * ```
-                 * <div i18n>translatable attribute</div>
-                 * ```
-                 */
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                  `  <file original="ng.template" id="ngi18n">`,
-                  `    <unit id="1933478729560469763">`,
-                  `      <notes>`,
-                  `        <note category="location">file.ts:2</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>translatable attribute</source>`,
-                  `        <target>etubirtta elbatalsnart</target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(result.translations[ɵcomputeMsgId('translatable attribute', '')])
-                    .toEqual(ɵmakeParsedTranslation(['etubirtta elbatalsnart']));
-              });
-
-              it('should extract translations with simple placeholders', () => {
-                /**
-                 * Source HTML:
-                 *
-                 * ```
-                 * <div i18n>translatable element <b>with placeholders</b> {{ interpolation}}</div>
-                 * ```
-                 */
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                  `  <file original="ng.template" id="ngi18n">`,
-                  `    <unit id="6949438802869886378">`,
-                  `      <notes>`,
-                  `        <note category="location">file.ts:3</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>translatable element <pc id="0" equivStart="START_BOLD_TEXT" equivEnd="CLOSE_BOLD_TEXT" type="fmt" dispStart="&lt;b&gt;" dispEnd="&lt;/b&gt;">with placeholders</pc> <ph id="1" equiv="INTERPOLATION" disp="{{ interpolation}}"/></source>`,
-                  `        <target><ph id="1" equiv="INTERPOLATION" disp="{{ interpolation}}"/> tnemele elbatalsnart <pc id="0" equivStart="START_BOLD_TEXT" equivEnd="CLOSE_BOLD_TEXT" type="fmt" dispStart="&lt;b&gt;" dispEnd="&lt;/b&gt;">sredlohecalp htiw</pc></target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(
-                    result.translations[ɵcomputeMsgId(
-                        'translatable element {$START_BOLD_TEXT}with placeholders{$CLOSE_BOLD_TEXT} {$INTERPOLATION}')])
-                    .toEqual(ɵmakeParsedTranslation(
-                        ['', ' tnemele elbatalsnart ', 'sredlohecalp htiw', ''],
-                        ['INTERPOLATION', 'START_BOLD_TEXT', 'CLOSE_BOLD_TEXT']));
-              });
-
-              it('should extract nested placeholder containers (i.e. nested HTML elements)', () => {
-                /**
-                 * Source HTML:
-                 *
-                 * ```
-                 * <div i18n>
-                 *   translatable <span>element <b>with placeholders</b></span> {{ interpolation}}
-                 * </div>
-                 * ```
-                 */
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                  `  <file original="ng.template" id="ngi18n">`,
-                  `    <unit id="9051630253697141670">`,
-                  `      <notes>`,
-                  `        <note category="location">file.ts:3</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>translatable <pc id="0" equivStart="START_TAG_SPAN" equivEnd="CLOSE_TAG_SPAN" type="other"` +
-                      ` dispStart="&lt;span&gt;" dispEnd="&lt;/span&gt;">element <pc id="1" equivStart="START_BOLD_TEXT" equivEnd=` +
-                      `"CLOSE_BOLD_TEXT" type="fmt" dispStart="&lt;b&gt;" dispEnd="&lt;/b&gt;">with placeholders</pc></pc>` +
-                      ` <ph id="2" equiv="INTERPOLATION" disp="{{ interpolation}}"/></source>`,
-                  `        <target><pc id="0" equivStart="START_TAG_SPAN" equivEnd="CLOSE_TAG_SPAN" type="fmt" dispStart="&lt;` +
-                      `span&gt;" dispEnd="&lt;/span&gt;"><ph id="2" equiv="INTERPOLATION" disp="{{ interpolation}}"/> tnemele</pc>` +
-                      ` elbatalsnart <pc id="1" equivStart="START_BOLD_TEXT" equivEnd="CLOSE_BOLD_TEXT" type="fmt" dispStart=` +
-                      `"&lt;b&gt;" dispEnd="&lt;/b&gt;">sredlohecalp htiw</pc></target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(
-                    result.translations[ɵcomputeMsgId(
-                        'translatable {$START_TAG_SPAN}element {$START_BOLD_TEXT}with placeholders' +
-                        '{$CLOSE_BOLD_TEXT}{$CLOSE_TAG_SPAN} {$INTERPOLATION}')])
-                    .toEqual(ɵmakeParsedTranslation(
-                        ['', '', ' tnemele', ' elbatalsnart ', 'sredlohecalp htiw', ''], [
-                          'START_TAG_SPAN',
-                          'INTERPOLATION',
-                          'CLOSE_TAG_SPAN',
-                          'START_BOLD_TEXT',
-                          'CLOSE_BOLD_TEXT',
-                        ]));
-              });
-
-              it('should extract translations with simple ICU expressions', () => {
-                /**
-                 * Source HTML:
-                 *
-                 * ```
-                 * <div i18n>{VAR_PLURAL, plural, =0 {<p>test</p>} }</div>
-                 * ```
-                 */
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                  `  <file original="ng.template" id="ngi18n">`,
-                  `    <unit id="2874455947211586270">`,
-                  `      <notes>`,
-                  `        <note category="location">file.ts:4</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>{VAR_PLURAL, plural, =0 {<pc id="0" equivStart="START_PARAGRAPH" equivEnd="CLOSE_PARAGRAPH" type="other" dispStart="&lt;p&gt;" dispEnd="&lt;/p&gt;">test</pc>} }</source>`,
-                  `        <target>{VAR_PLURAL, plural, =0 {<pc id="0" equivStart="START_PARAGRAPH" equivEnd="CLOSE_PARAGRAPH" type="other" dispStart="&lt;p&gt;" dispEnd="&lt;/p&gt;">TEST</pc>} }</target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(result.translations[ɵcomputeMsgId(
-                           '{VAR_PLURAL, plural, =0 {{START_PARAGRAPH}test{CLOSE_PARAGRAPH}}}')])
-                    .toEqual(ɵmakeParsedTranslation(
-                        ['{VAR_PLURAL, plural, =0 {{START_PARAGRAPH}TEST{CLOSE_PARAGRAPH}}}'], []));
-              });
-
-              it('should extract translations with duplicate source messages', () => {
-                /**
-                 * Source HTML:
-                 *
-                 * ```
-                 * <div i18n>foo</div>
-                 * <div i18n="m|d@@i">foo</div>
-                 * <div i18=""m|d@@bar>foo</div>
-                 * ```
-                 */
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                  `  <file original="ng.template" id="ngi18n">`,
-                  `    <unit id="9205907420411818817">`,
-                  `      <notes>`,
-                  `        <note category="description">d</note>`,
-                  `        <note category="meaning">m</note>`,
-                  `        <note category="location">file.ts:5</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>foo</source>`,
-                  `        <target>oof</target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `    <unit id="i">`,
-                  `      <notes>`,
-                  `        <note category="description">d</note>`,
-                  `        <note category="meaning">m</note>`,
-                  `        <note category="location">file.ts:5</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>foo</source>`,
-                  `        <target>toto</target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `    <unit id="bar">`,
-                  `      <notes>`,
-                  `        <note category="description">d</note>`,
-                  `        <note category="meaning">m</note>`,
-                  `        <note category="location">file.ts:5</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>foo</source>`,
-                  `        <target>tata</target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(result.translations[ɵcomputeMsgId('foo')])
-                    .toEqual(ɵmakeParsedTranslation(['oof']));
-                expect(result.translations['i']).toEqual(ɵmakeParsedTranslation(['toto']));
-                expect(result.translations['bar']).toEqual(ɵmakeParsedTranslation(['tata']));
-              });
-
-              it('should extract translations with only placeholders, which are re-ordered', () => {
-                /**
-                 * Source HTML:
-                 *
-                 * ```
-                 * <div i18n><br><img/><img/></div>
-                 * ```
-                 */
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                  `  <file original="ng.template" id="ngi18n">`,
-                  `    <unit id="7118057989405618448">`,
-                  `      <notes>`,
-                  `        <note category="description">ph names</note>`,
-                  `        <note category="location">file.ts:7</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source><ph id="0" equiv="LINE_BREAK" type="fmt" disp="&lt;br/&gt;"/><ph id="1" equiv="TAG_IMG" type="image" disp="&lt;img/&gt;"/><ph id="2" equiv="TAG_IMG_1" type="image" disp="&lt;img/&gt;"/></source>`,
-                  `        <target><ph id="2" equiv="TAG_IMG_1" type="image" disp="&lt;img/&gt;"/><ph id="1" equiv="TAG_IMG" type="image" disp="&lt;img/&gt;"/><ph id="0" equiv="LINE_BREAK" type="fmt" disp="&lt;br/&gt;"/></target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(result.translations[ɵcomputeMsgId('{$LINE_BREAK}{$TAG_IMG}{$TAG_IMG_1}')])
-                    .toEqual(ɵmakeParsedTranslation(
-                        ['', '', '', ''], ['TAG_IMG_1', 'TAG_IMG', 'LINE_BREAK']));
-              });
-
-              it('should extract translations with empty target', () => {
-                /**
-                 * Source HTML:
-                 *
-                 * ```
-                 * <div i18n>hello <span></span></div>
-                 * ```
-                 */
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                  `  <file original="ng.template" id="ngi18n">`,
-                  `    <unit id="2826198357052921524">`,
-                  `      <notes>`,
-                  `        <note category="description">empty element</note>`,
-                  `        <note category="location">file.ts:8</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>hello <pc id="0" equivStart="START_TAG_SPAN" equivEnd="CLOSE_TAG_SPAN" type="other" dispStart="&lt;span&gt;" dispEnd="&lt;/span&gt;"></pc></source>`,
-                  `        <target></target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(
-                    result.translations[ɵcomputeMsgId('hello {$START_TAG_SPAN}{$CLOSE_TAG_SPAN}')])
-                    .toEqual(ɵmakeParsedTranslation(['']));
-              });
-
-              it('should extract translations with deeply nested ICUs', () => {
-                /**
-                 * Source HTML:
-                 *
-                 * ```
-                 * Test: { count, plural, =0 { { sex, select, other {<p>deeply nested</p>}} }
-                 * =other {a lot}}
-                 * ```
-                 *
-                 * Note that the message gets split into two translation units:
-                 *  * The first one contains the outer message with an `ICU` placeholder
-                 *  * The second one is the ICU expansion itself
-                 *
-                 * Note that special markers `VAR_PLURAL` and `VAR_SELECT` are added, which are then
-                 * replaced by IVY at runtime with the actual values being rendered by the ICU
-                 * expansion.
-                 */
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                  `  <file original="ng.template" id="ngi18n">`,
-                  `    <unit id="980940425376233536">`,
-                  `      <notes>`,
-                  `        <note category="location">file.ts:10</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>Test: <ph id="0" equiv="ICU" disp="{ count, plural, =0 {...} =other {...}}"/></source>`,
-                  `        <target>Le test: <ph id="0" equiv="ICU" disp="{ count, plural, =0 {...} =other {...}}"/></target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `    <unit id="5207293143089349404">`,
-                  `      <notes>`,
-                  `        <note category="location">file.ts:10</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {<pc id="0" equivStart="START_PARAGRAPH" equivEnd="CLOSE_PARAGRAPH" type="other" dispStart="&lt;p&gt;" dispEnd="&lt;/p&gt;">deeply nested</pc>}}} =other {a lot}}</source>`,
-                  `        <target>{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {<pc id="0" equivStart="START_PARAGRAPH" equivEnd="CLOSE_PARAGRAPH" type="other" dispStart="&lt;p&gt;" dispEnd="&lt;/p&gt;">profondément imbriqué</pc>}}} =other {beaucoup}}</target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(result.translations[ɵcomputeMsgId('Test: {$ICU}')])
-                    .toEqual(ɵmakeParsedTranslation(['Le test: ', ''], ['ICU']));
-                expect(
-                    result.translations[ɵcomputeMsgId(
-                        '{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {{START_PARAGRAPH}deeply nested{CLOSE_PARAGRAPH}}}} =other {beaucoup}}')])
-                    .toEqual(ɵmakeParsedTranslation([
-                      '{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {{START_PARAGRAPH}profondément imbriqué{CLOSE_PARAGRAPH}}}} =other {beaucoup}}'
+          it('should extract the locale from the file contents', () => {
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+              `  <file original="ng.template" id="ngi18n">`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(result.locale).toEqual('fr');
+          });
+
+          it('should return undefined locale if there is no locale in the file', () => {
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en">`,
+              `  <file original="ng.template" id="ngi18n">`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(result.locale).toBeUndefined();
+          });
+
+          it('should extract basic messages', () => {
+            /**
+             * Source HTML:
+             *
+             * ```
+             * <div i18n>translatable attribute</div>
+             * ```
+             */
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+              `  <file original="ng.template" id="ngi18n">`,
+              `    <unit id="1933478729560469763">`,
+              `      <notes>`,
+              `        <note category="location">file.ts:2</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>translatable attribute</source>`,
+              `        <target>etubirtta elbatalsnart</target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(result.translations[ɵcomputeMsgId('translatable attribute', '')])
+                .toEqual(ɵmakeParsedTranslation(['etubirtta elbatalsnart']));
+          });
+
+          it('should extract translations with simple placeholders', () => {
+            /**
+             * Source HTML:
+             *
+             * ```
+             * <div i18n>translatable element <b>with placeholders</b> {{ interpolation}}</div>
+             * ```
+             */
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+              `  <file original="ng.template" id="ngi18n">`,
+              `    <unit id="6949438802869886378">`,
+              `      <notes>`,
+              `        <note category="location">file.ts:3</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>translatable element <pc id="0" equivStart="START_BOLD_TEXT" equivEnd="CLOSE_BOLD_TEXT" type="fmt" dispStart="&lt;b&gt;" dispEnd="&lt;/b&gt;">with placeholders</pc> <ph id="1" equiv="INTERPOLATION" disp="{{ interpolation}}"/></source>`,
+              `        <target><ph id="1" equiv="INTERPOLATION" disp="{{ interpolation}}"/> tnemele elbatalsnart <pc id="0" equivStart="START_BOLD_TEXT" equivEnd="CLOSE_BOLD_TEXT" type="fmt" dispStart="&lt;b&gt;" dispEnd="&lt;/b&gt;">sredlohecalp htiw</pc></target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(
+                result.translations[ɵcomputeMsgId(
+                    'translatable element {$START_BOLD_TEXT}with placeholders{$CLOSE_BOLD_TEXT} {$INTERPOLATION}')])
+                .toEqual(ɵmakeParsedTranslation(
+                    ['', ' tnemele elbatalsnart ', 'sredlohecalp htiw', ''],
+                    ['INTERPOLATION', 'START_BOLD_TEXT', 'CLOSE_BOLD_TEXT']));
+          });
+
+          it('should extract nested placeholder containers (i.e. nested HTML elements)', () => {
+            /**
+             * Source HTML:
+             *
+             * ```
+             * <div i18n>
+             *   translatable <span>element <b>with placeholders</b></span> {{ interpolation}}
+             * </div>
+             * ```
+             */
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+              `  <file original="ng.template" id="ngi18n">`,
+              `    <unit id="9051630253697141670">`,
+              `      <notes>`,
+              `        <note category="location">file.ts:3</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>translatable <pc id="0" equivStart="START_TAG_SPAN" equivEnd="CLOSE_TAG_SPAN" type="other"` +
+                  ` dispStart="&lt;span&gt;" dispEnd="&lt;/span&gt;">element <pc id="1" equivStart="START_BOLD_TEXT" equivEnd=` +
+                  `"CLOSE_BOLD_TEXT" type="fmt" dispStart="&lt;b&gt;" dispEnd="&lt;/b&gt;">with placeholders</pc></pc>` +
+                  ` <ph id="2" equiv="INTERPOLATION" disp="{{ interpolation}}"/></source>`,
+              `        <target><pc id="0" equivStart="START_TAG_SPAN" equivEnd="CLOSE_TAG_SPAN" type="fmt" dispStart="&lt;` +
+                  `span&gt;" dispEnd="&lt;/span&gt;"><ph id="2" equiv="INTERPOLATION" disp="{{ interpolation}}"/> tnemele</pc>` +
+                  ` elbatalsnart <pc id="1" equivStart="START_BOLD_TEXT" equivEnd="CLOSE_BOLD_TEXT" type="fmt" dispStart=` +
+                  `"&lt;b&gt;" dispEnd="&lt;/b&gt;">sredlohecalp htiw</pc></target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(result.translations[ɵcomputeMsgId(
+                       'translatable {$START_TAG_SPAN}element {$START_BOLD_TEXT}with placeholders' +
+                       '{$CLOSE_BOLD_TEXT}{$CLOSE_TAG_SPAN} {$INTERPOLATION}')])
+                .toEqual(ɵmakeParsedTranslation(
+                    ['', '', ' tnemele', ' elbatalsnart ', 'sredlohecalp htiw', ''], [
+                      'START_TAG_SPAN',
+                      'INTERPOLATION',
+                      'CLOSE_TAG_SPAN',
+                      'START_BOLD_TEXT',
+                      'CLOSE_BOLD_TEXT',
                     ]));
-              });
-
-              it('should extract translations containing multiple lines', () => {
-                /**
-                 * Source HTML:
-                 *
-                 * ```
-                 * <div i18n>multi
-                 * lines</div>
-                 * ```
-                 */
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                  `  <file original="ng.template" id="ngi18n">`,
-                  `    <unit id="2340165783990709777">`,
-                  `      <notes>`,
-                  `        <note category="location">file.ts:11,12</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>multi\nlines</source>`,
-                  `        <target>multi\nlignes</target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(result.translations[ɵcomputeMsgId('multi\nlines')])
-                    .toEqual(ɵmakeParsedTranslation(['multi\nlignes']));
-              });
-
-              it('should extract translations with <mrk> elements', () => {
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                  `  <file original="ng.template" id="ngi18n">`,
-                  `    <unit id="mrk-test">`,
-                  `      <segment>`,
-                  `        <source>First sentence.</source>`,
-                  `        <target>Translated <mrk id="m1" type="comment" ref="#n1">first sentence</mrk>.</target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `    <unit id="mrk-test2">`,
-                  `      <segment>`,
-                  `        <source>First sentence. Second sentence.</source>`,
-                  `        <target>Translated <mrk id="m1" type="comment" ref="#n1"><mrk id="m2" type="comment" ref="#n1">first</mrk> sentence</mrk>.</target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(result.translations['mrk-test'])
-                    .toEqual(ɵmakeParsedTranslation(['Translated first sentence.']));
-                expect(result.translations['mrk-test2'])
-                    .toEqual(ɵmakeParsedTranslation(['Translated first sentence.']));
-              });
-
-              it('should merge messages from each `<file>` element', () => {
-                /**
-                 * Source HTML:
-                 *
-                 * ```
-                 * <div i18n>translatable attribute</div>
-                 * ```
-                 *
-                 * ```
-                 * <div i18n>translatable element <b>with placeholders</b> {{ interpolation}}</div>
-                 * ```
-                 */
-                const XLIFF = [
-                  `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                  `  <file original="ng.template" id="file-1">`,
-                  `    <unit id="1933478729560469763">`,
-                  `      <notes>`,
-                  `        <note category="location">file.ts:2</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>translatable attribute</source>`,
-                  `        <target>etubirtta elbatalsnart</target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `  </file>`,
-                  `  <file original="ng.template" id="file-2">`,
-                  `    <unit id="5057824347511785081">`,
-                  `      <notes>`,
-                  `        <note category="location">file.ts:3</note>`,
-                  `      </notes>`,
-                  `      <segment>`,
-                  `        <source>translatable element <pc id="0" equivStart="START_BOLD_TEXT" equivEnd="CLOSE_BOLD_TEXT" type="fmt" dispStart="&lt;b&gt;" dispEnd="&lt;/b&gt;">with placeholders</pc> <ph id="1" equiv="INTERPOLATION" disp="{{ interpolation}}"/></source>`,
-                  `        <target><ph id="1" equiv="INTERPOLATION" disp="{{ interpolation}}"/> tnemele elbatalsnart <pc id="0" equivStart="START_BOLD_TEXT" equivEnd="CLOSE_BOLD_TEXT" type="fmt" dispStart="&lt;b&gt;" dispEnd="&lt;/b&gt;">sredlohecalp htiw</pc></target>`,
-                  `      </segment>`,
-                  `    </unit>`,
-                  `  </file>`,
-                  `</xliff>`,
-                ].join('\n');
-                const result = doParse('/some/file.xlf', XLIFF);
-                expect(result.translations[ɵcomputeMsgId('translatable attribute', '')])
-                    .toEqual(ɵmakeParsedTranslation(['etubirtta elbatalsnart']));
-                expect(
-                    result.translations[ɵcomputeMsgId(
-                        'translatable element {$START_BOLD_TEXT}with placeholders{$LOSE_BOLD_TEXT} {$INTERPOLATION}')])
-                    .toEqual(ɵmakeParsedTranslation(
-                        ['', ' tnemele elbatalsnart ', 'sredlohecalp htiw', ''],
-                        ['INTERPOLATION', 'START_BOLD_TEXT', 'CLOSE_BOLD_TEXT']));
-              });
-
-              describe('[structure errors]', () => {
-                it('should provide a diagnostic error when a trans-unit has no translation', () => {
-                  const XLIFF = [
-                    `<?xml version="1.0" encoding="UTF-8" ?>`,
-                    `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                    `  <file original="ng.template" id="ngi18n">`,
-                    `    <unit id="missingtarget">`,
-                    `      <segment>`,
-                    `        <source/>`,
-                    `      </segment>`,
-                    `    </unit>`,
-                    `  </file>`,
-                    `</xliff>`,
-                  ].join('\n');
-
-                  expectToFail('/some/file.xlf', XLIFF, /Missing required <target> element/, [
-                    `Missing required <target> element ("`,
-                    `  <file original="ng.template" id="ngi18n">`,
-                    `    <unit id="missingtarget">`,
-                    `      [ERROR ->]<segment>`,
-                    `        <source/>`,
-                    `      </segment>`,
-                    `"): /some/file.xlf@4:6`,
-                  ].join('\n'));
-                });
-
+          });
+
+          it('should extract translations with simple ICU expressions', () => {
+            /**
+             * Source HTML:
+             *
+             * ```
+             * <div i18n>{VAR_PLURAL, plural, =0 {<p>test</p>} }</div>
+             * ```
+             */
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+              `  <file original="ng.template" id="ngi18n">`,
+              `    <unit id="2874455947211586270">`,
+              `      <notes>`,
+              `        <note category="location">file.ts:4</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>{VAR_PLURAL, plural, =0 {<pc id="0" equivStart="START_PARAGRAPH" equivEnd="CLOSE_PARAGRAPH" type="other" dispStart="&lt;p&gt;" dispEnd="&lt;/p&gt;">test</pc>} }</source>`,
+              `        <target>{VAR_PLURAL, plural, =0 {<pc id="0" equivStart="START_PARAGRAPH" equivEnd="CLOSE_PARAGRAPH" type="other" dispStart="&lt;p&gt;" dispEnd="&lt;/p&gt;">TEST</pc>} }</target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(result.translations[ɵcomputeMsgId(
+                       '{VAR_PLURAL, plural, =0 {{START_PARAGRAPH}test{CLOSE_PARAGRAPH}}}')])
+                .toEqual(ɵmakeParsedTranslation(
+                    ['{VAR_PLURAL, plural, =0 {{START_PARAGRAPH}TEST{CLOSE_PARAGRAPH}}}'], []));
+          });
+
+          it('should extract translations with duplicate source messages', () => {
+            /**
+             * Source HTML:
+             *
+             * ```
+             * <div i18n>foo</div>
+             * <div i18n="m|d@@i">foo</div>
+             * <div i18=""m|d@@bar>foo</div>
+             * ```
+             */
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+              `  <file original="ng.template" id="ngi18n">`,
+              `    <unit id="9205907420411818817">`,
+              `      <notes>`,
+              `        <note category="description">d</note>`,
+              `        <note category="meaning">m</note>`,
+              `        <note category="location">file.ts:5</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>foo</source>`,
+              `        <target>oof</target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `    <unit id="i">`,
+              `      <notes>`,
+              `        <note category="description">d</note>`,
+              `        <note category="meaning">m</note>`,
+              `        <note category="location">file.ts:5</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>foo</source>`,
+              `        <target>toto</target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `    <unit id="bar">`,
+              `      <notes>`,
+              `        <note category="description">d</note>`,
+              `        <note category="meaning">m</note>`,
+              `        <note category="location">file.ts:5</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>foo</source>`,
+              `        <target>tata</target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(result.translations[ɵcomputeMsgId('foo')])
+                .toEqual(ɵmakeParsedTranslation(['oof']));
+            expect(result.translations['i']).toEqual(ɵmakeParsedTranslation(['toto']));
+            expect(result.translations['bar']).toEqual(ɵmakeParsedTranslation(['tata']));
+          });
+
+          it('should extract translations with only placeholders, which are re-ordered', () => {
+            /**
+             * Source HTML:
+             *
+             * ```
+             * <div i18n><br><img/><img/></div>
+             * ```
+             */
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+              `  <file original="ng.template" id="ngi18n">`,
+              `    <unit id="7118057989405618448">`,
+              `      <notes>`,
+              `        <note category="description">ph names</note>`,
+              `        <note category="location">file.ts:7</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source><ph id="0" equiv="LINE_BREAK" type="fmt" disp="&lt;br/&gt;"/><ph id="1" equiv="TAG_IMG" type="image" disp="&lt;img/&gt;"/><ph id="2" equiv="TAG_IMG_1" type="image" disp="&lt;img/&gt;"/></source>`,
+              `        <target><ph id="2" equiv="TAG_IMG_1" type="image" disp="&lt;img/&gt;"/><ph id="1" equiv="TAG_IMG" type="image" disp="&lt;img/&gt;"/><ph id="0" equiv="LINE_BREAK" type="fmt" disp="&lt;br/&gt;"/></target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(result.translations[ɵcomputeMsgId('{$LINE_BREAK}{$TAG_IMG}{$TAG_IMG_1}')])
+                .toEqual(ɵmakeParsedTranslation(
+                    ['', '', '', ''], ['TAG_IMG_1', 'TAG_IMG', 'LINE_BREAK']));
+          });
+
+          it('should extract translations with empty target', () => {
+            /**
+             * Source HTML:
+             *
+             * ```
+             * <div i18n>hello <span></span></div>
+             * ```
+             */
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+              `  <file original="ng.template" id="ngi18n">`,
+              `    <unit id="2826198357052921524">`,
+              `      <notes>`,
+              `        <note category="description">empty element</note>`,
+              `        <note category="location">file.ts:8</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>hello <pc id="0" equivStart="START_TAG_SPAN" equivEnd="CLOSE_TAG_SPAN" type="other" dispStart="&lt;span&gt;" dispEnd="&lt;/span&gt;"></pc></source>`,
+              `        <target></target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(result.translations[ɵcomputeMsgId('hello {$START_TAG_SPAN}{$CLOSE_TAG_SPAN}')])
+                .toEqual(ɵmakeParsedTranslation(['']));
+          });
+
+          it('should extract translations with deeply nested ICUs', () => {
+            /**
+             * Source HTML:
+             *
+             * ```
+             * Test: { count, plural, =0 { { sex, select, other {<p>deeply nested</p>}} }
+             * =other {a lot}}
+             * ```
+             *
+             * Note that the message gets split into two translation units:
+             *  * The first one contains the outer message with an `ICU` placeholder
+             *  * The second one is the ICU expansion itself
+             *
+             * Note that special markers `VAR_PLURAL` and `VAR_SELECT` are added, which are then
+             * replaced by IVY at runtime with the actual values being rendered by the ICU
+             * expansion.
+             */
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+              `  <file original="ng.template" id="ngi18n">`,
+              `    <unit id="980940425376233536">`,
+              `      <notes>`,
+              `        <note category="location">file.ts:10</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>Test: <ph id="0" equiv="ICU" disp="{ count, plural, =0 {...} =other {...}}"/></source>`,
+              `        <target>Le test: <ph id="0" equiv="ICU" disp="{ count, plural, =0 {...} =other {...}}"/></target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `    <unit id="5207293143089349404">`,
+              `      <notes>`,
+              `        <note category="location">file.ts:10</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {<pc id="0" equivStart="START_PARAGRAPH" equivEnd="CLOSE_PARAGRAPH" type="other" dispStart="&lt;p&gt;" dispEnd="&lt;/p&gt;">deeply nested</pc>}}} =other {a lot}}</source>`,
+              `        <target>{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {<pc id="0" equivStart="START_PARAGRAPH" equivEnd="CLOSE_PARAGRAPH" type="other" dispStart="&lt;p&gt;" dispEnd="&lt;/p&gt;">profondément imbriqué</pc>}}} =other {beaucoup}}</target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(result.translations[ɵcomputeMsgId('Test: {$ICU}')])
+                .toEqual(ɵmakeParsedTranslation(['Le test: ', ''], ['ICU']));
+            expect(
+                result.translations[ɵcomputeMsgId(
+                    '{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {{START_PARAGRAPH}deeply nested{CLOSE_PARAGRAPH}}}} =other {beaucoup}}')])
+                .toEqual(ɵmakeParsedTranslation([
+                  '{VAR_PLURAL, plural, =0 {{VAR_SELECT, select, other {{START_PARAGRAPH}profondément imbriqué{CLOSE_PARAGRAPH}}}} =other {beaucoup}}'
+                ]));
+          });
+
+          it('should extract translations containing multiple lines', () => {
+            /**
+             * Source HTML:
+             *
+             * ```
+             * <div i18n>multi
+             * lines</div>
+             * ```
+             */
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+              `  <file original="ng.template" id="ngi18n">`,
+              `    <unit id="2340165783990709777">`,
+              `      <notes>`,
+              `        <note category="location">file.ts:11,12</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>multi\nlines</source>`,
+              `        <target>multi\nlignes</target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(result.translations[ɵcomputeMsgId('multi\nlines')])
+                .toEqual(ɵmakeParsedTranslation(['multi\nlignes']));
+          });
+
+          it('should extract translations with <mrk> elements', () => {
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+              `  <file original="ng.template" id="ngi18n">`,
+              `    <unit id="mrk-test">`,
+              `      <segment>`,
+              `        <source>First sentence.</source>`,
+              `        <target>Translated <mrk id="m1" type="comment" ref="#n1">first sentence</mrk>.</target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `    <unit id="mrk-test2">`,
+              `      <segment>`,
+              `        <source>First sentence. Second sentence.</source>`,
+              `        <target>Translated <mrk id="m1" type="comment" ref="#n1"><mrk id="m2" type="comment" ref="#n1">first</mrk> sentence</mrk>.</target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(result.translations['mrk-test'])
+                .toEqual(ɵmakeParsedTranslation(['Translated first sentence.']));
+            expect(result.translations['mrk-test2'])
+                .toEqual(ɵmakeParsedTranslation(['Translated first sentence.']));
+          });
+
+          it('should merge messages from each `<file>` element', () => {
+            /**
+             * Source HTML:
+             *
+             * ```
+             * <div i18n>translatable attribute</div>
+             * ```
+             *
+             * ```
+             * <div i18n>translatable element <b>with placeholders</b> {{ interpolation}}</div>
+             * ```
+             */
+            const XLIFF = [
+              `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+              `  <file original="ng.template" id="file-1">`,
+              `    <unit id="1933478729560469763">`,
+              `      <notes>`,
+              `        <note category="location">file.ts:2</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>translatable attribute</source>`,
+              `        <target>etubirtta elbatalsnart</target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `  </file>`,
+              `  <file original="ng.template" id="file-2">`,
+              `    <unit id="5057824347511785081">`,
+              `      <notes>`,
+              `        <note category="location">file.ts:3</note>`,
+              `      </notes>`,
+              `      <segment>`,
+              `        <source>translatable element <pc id="0" equivStart="START_BOLD_TEXT" equivEnd="CLOSE_BOLD_TEXT" type="fmt" dispStart="&lt;b&gt;" dispEnd="&lt;/b&gt;">with placeholders</pc> <ph id="1" equiv="INTERPOLATION" disp="{{ interpolation}}"/></source>`,
+              `        <target><ph id="1" equiv="INTERPOLATION" disp="{{ interpolation}}"/> tnemele elbatalsnart <pc id="0" equivStart="START_BOLD_TEXT" equivEnd="CLOSE_BOLD_TEXT" type="fmt" dispStart="&lt;b&gt;" dispEnd="&lt;/b&gt;">sredlohecalp htiw</pc></target>`,
+              `      </segment>`,
+              `    </unit>`,
+              `  </file>`,
+              `</xliff>`,
+            ].join('\n');
+            const result = doParse('/some/file.xlf', XLIFF);
+            expect(result.translations[ɵcomputeMsgId('translatable attribute', '')])
+                .toEqual(ɵmakeParsedTranslation(['etubirtta elbatalsnart']));
+            expect(
+                result.translations[ɵcomputeMsgId(
+                    'translatable element {$START_BOLD_TEXT}with placeholders{$LOSE_BOLD_TEXT} {$INTERPOLATION}')])
+                .toEqual(ɵmakeParsedTranslation(
+                    ['', ' tnemele elbatalsnart ', 'sredlohecalp htiw', ''],
+                    ['INTERPOLATION', 'START_BOLD_TEXT', 'CLOSE_BOLD_TEXT']));
+          });
+
+          describe('[structure errors]', () => {
+            it('should provide a diagnostic warning when a trans-unit has no translation target but does have a source',
+               () => {
+                 const XLIFF = [
+                   `<?xml version="1.0" encoding="UTF-8" ?>`,
+                   `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+                   `  <file original="ng.template" id="ngi18n">`,
+                   `    <unit id="missingtarget">`,
+                   `      <segment>`,
+                   `        <source/>`,
+                   `      </segment>`,
+                   `    </unit>`,
+                   `  </file>`,
+                   `</xliff>`,
+                 ].join('\n');
+
+                 const result = doParse('/some/file.xlf', XLIFF);
+                 expect(result.diagnostics.messages.length).toEqual(1);
+                 expect(result.diagnostics.messages[0].message).toEqual([
+                   `Missing <target> element ("`,
+                   `  <file original="ng.template" id="ngi18n">`,
+                   `    <unit id="missingtarget">`,
+                   `      [WARNING ->]<segment>`,
+                   `        <source/>`,
+                   `      </segment>`,
+                   `"): /some/file.xlf@4:6`,
+                 ].join('\n'));
+               });
+
+            it('should provide a diagnostic error when a trans-unit has no translation target nor source',
+               () => {
+                 const XLIFF = [
+                   `<?xml version="1.0" encoding="UTF-8" ?>`,
+                   `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+                   `  <file original="ng.template" id="ngi18n">`,
+                   `    <unit id="missingtarget">`,
+                   `      <segment>`,
+                   `      </segment>`,
+                   `    </unit>`,
+                   `  </file>`,
+                   `</xliff>`,
+                 ].join('\n');
+
+                 expectToFail(
+                     '/some/file.xlf', XLIFF,
+                     /Missing required element: one of <target> or <source> is required/, [
+                       `Missing required element: one of <target> or <source> is required ("`,
+                       `  <file original="ng.template" id="ngi18n">`,
+                       `    <unit id="missingtarget">`,
+                       `      [ERROR ->]<segment>`,
+                       `      </segment>`,
+                       `    </unit>`,
+                       `"): /some/file.xlf@4:6`,
+                     ].join('\n'));
+               });
+
+
+            it('should provide a diagnostic error when a trans-unit has no id attribute', () => {
+              const XLIFF = [
+                `<?xml version="1.0" encoding="UTF-8" ?>`,
+                `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+                `  <file original="ng.template" id="ngi18n">`,
+                `    <unit>`,
+                `      <segment>`,
+                `        <source/>`,
+                `        <target/>`,
+                `      </segment>`,
+                `    </unit>`,
+                `  </file>`,
+                `</xliff>`,
+              ].join('\n');
+
+              expectToFail('/some/file.xlf', XLIFF, /Missing required "id" attribute/, [
+                `Missing required "id" attribute on <trans-unit> element. ("s:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+                `  <file original="ng.template" id="ngi18n">`,
+                `    [ERROR ->]<unit>`,
+                `      <segment>`,
+                `        <source/>`,
+                `"): /some/file.xlf@3:4`,
+              ].join('\n'));
+            });
 
-                it('should provide a diagnostic error when a trans-unit has no id attribute', () => {
-                  const XLIFF = [
-                    `<?xml version="1.0" encoding="UTF-8" ?>`,
-                    `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                    `  <file original="ng.template" id="ngi18n">`,
-                    `    <unit>`,
-                    `      <segment>`,
-                    `        <source/>`,
-                    `        <target/>`,
+            it('should provide a diagnostic error on duplicate trans-unit id', () => {
+              const XLIFF = [
+                `<?xml version="1.0" encoding="UTF-8" ?>`,
+                `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+                `  <file original="ng.template" id="ngi18n">`,
+                `    <unit id="deadbeef">`,
+                `      <segment>`,
+                `        <source/>`,
+                `        <target/>`,
+                `      </segment>`,
+                `    </unit>`,
+                `    <unit id="deadbeef">`,
+                `      <segment>`,
+                `        <source/>`,
+                `        <target/>`,
+                `      </segment>`,
+                `    </unit>`,
+                `  </file>`,
+                `</xliff>`,
+              ].join('\n');
+
+              expectToFail(
+                  '/some/file.xlf', XLIFF, /Duplicated translations for message "deadbeef"/, [
+                    `Duplicated translations for message "deadbeef" ("`,
                     `      </segment>`,
                     `    </unit>`,
-                    `  </file>`,
-                    `</xliff>`,
-                  ].join('\n');
-
-                  expectToFail('/some/file.xlf', XLIFF, /Missing required "id" attribute/, [
-                    `Missing required "id" attribute on <trans-unit> element. ("s:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                    `  <file original="ng.template" id="ngi18n">`,
-                    `    [ERROR ->]<unit>`,
+                    `    [ERROR ->]<unit id="deadbeef">`,
                     `      <segment>`,
                     `        <source/>`,
-                    `"): /some/file.xlf@3:4`,
+                    '"): /some/file.xlf@9:4',
                   ].join('\n'));
-                });
-
-                it('should provide a diagnostic error on duplicate trans-unit id', () => {
-                  const XLIFF = [
-                    `<?xml version="1.0" encoding="UTF-8" ?>`,
-                    `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                    `  <file original="ng.template" id="ngi18n">`,
-                    `    <unit id="deadbeef">`,
-                    `      <segment>`,
-                    `        <source/>`,
-                    `        <target/>`,
-                    `      </segment>`,
-                    `    </unit>`,
-                    `    <unit id="deadbeef">`,
-                    `      <segment>`,
-                    `        <source/>`,
-                    `        <target/>`,
-                    `      </segment>`,
-                    `    </unit>`,
-                    `  </file>`,
-                    `</xliff>`,
-                  ].join('\n');
-
-                  expectToFail(
-                      '/some/file.xlf', XLIFF, /Duplicated translations for message "deadbeef"/, [
-                        `Duplicated translations for message "deadbeef" ("`,
-                        `      </segment>`,
-                        `    </unit>`,
-                        `    [ERROR ->]<unit id="deadbeef">`,
-                        `      <segment>`,
-                        `        <source/>`,
-                        '"): /some/file.xlf@9:4',
-                      ].join('\n'));
-                });
-              });
-
-              describe('[message errors]', () => {
-                it('should provide a diagnostic error on unknown message tags', () => {
-                  const XLIFF = [
-                    `<?xml version="1.0" encoding="UTF-8" ?>`,
-                    `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                    `  <file original="ng.template" id="ngi18n">`,
-                    `    <unit id="deadbeef">`,
-                    `      <segment>`,
-                    `        <source/>`,
-                    `        <target><b>msg should contain only ph and pc tags</b></target>`,
-                    `      </segment>`,
-                    `    </unit>`,
-                    `  </file>`,
-                    `</xliff>`,
-                  ].join('\n');
-
-                  expectToFail('/some/file.xlf', XLIFF, /Invalid element found in message/, [
-                    `Error: Invalid element found in message.`,
-                    `At /some/file.xlf@6:16:`,
-                    `...`,
-                    `        <source/>`,
-                    `        <target>[ERROR ->]<b>msg should contain only ph and pc tags</b></target>`,
-                    `      </segment>`,
-                    `...`,
-                    ``,
-                  ].join('\n'));
-                });
+            });
+          });
+
+          describe('[message errors]', () => {
+            it('should provide a diagnostic error on unknown message tags', () => {
+              const XLIFF = [
+                `<?xml version="1.0" encoding="UTF-8" ?>`,
+                `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+                `  <file original="ng.template" id="ngi18n">`,
+                `    <unit id="deadbeef">`,
+                `      <segment>`,
+                `        <source/>`,
+                `        <target><b>msg should contain only ph and pc tags</b></target>`,
+                `      </segment>`,
+                `    </unit>`,
+                `  </file>`,
+                `</xliff>`,
+              ].join('\n');
+
+              expectToFail('/some/file.xlf', XLIFF, /Invalid element found in message/, [
+                `Error: Invalid element found in message.`,
+                `At /some/file.xlf@6:16:`,
+                `...`,
+                `        <source/>`,
+                `        <target>[ERROR ->]<b>msg should contain only ph and pc tags</b></target>`,
+                `      </segment>`,
+                `...`,
+                ``,
+              ].join('\n'));
+            });
 
-                it('should provide a diagnostic error when a placeholder misses an id attribute',
-                   () => {
-                     const XLIFF = [
-                       `<?xml version="1.0" encoding="UTF-8" ?>`,
-                       `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
-                       `  <file original="ng.template" id="ngi18n">`,
-                       `    <unit id="deadbeef">`,
-                       `      <segment>`,
-                       `        <source/>`,
-                       `        <target><ph/></target>`,
-                       `      </segment>`,
-                       `    </unit>`,
-                       `  </file>`,
-                       `</xliff>`,
-                     ].join('\n');
-
-                     expectToFail('/some/file.xlf', XLIFF, /Missing required "equiv" attribute/, [
-                       `Error: Missing required "equiv" attribute:`,
-                       `At /some/file.xlf@6:16:`,
-                       `...`,
-                       `        <source/>`,
-                       `        <target>[ERROR ->]<ph/></target>`,
-                       `      </segment>`,
-                       `...`,
-                       ``,
-                     ].join('\n'));
-                   });
-              });
+            it('should provide a diagnostic error when a placeholder misses an id attribute', () => {
+              const XLIFF = [
+                `<?xml version="1.0" encoding="UTF-8" ?>`,
+                `<xliff version="2.0" xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en" trgLang="fr">`,
+                `  <file original="ng.template" id="ngi18n">`,
+                `    <unit id="deadbeef">`,
+                `      <segment>`,
+                `        <source/>`,
+                `        <target><ph/></target>`,
+                `      </segment>`,
+                `    </unit>`,
+                `  </file>`,
+                `</xliff>`,
+              ].join('\n');
+
+              expectToFail('/some/file.xlf', XLIFF, /Missing required "equiv" attribute/, [
+                `Error: Missing required "equiv" attribute:`,
+                `At /some/file.xlf@6:16:`,
+                `...`,
+                `        <source/>`,
+                `        <target>[ERROR ->]<ph/></target>`,
+                `      </segment>`,
+                `...`,
+                ``,
+              ].join('\n'));
             });
-      }
-    });
+          });
+        });
+  }
+});