fix(compiler): don't report parse error for interpolation inside stri…

…ng in property binding

Currently we check whether a property binding contains an interpolation using a regex so
that we can throw an error. The problem is that the regex doesn't account for quotes
which means that something like `[prop]="'{{ foo }}'"` will be considered an error, even
though it's not actually an interpolation.

These changes build on top of the logic from angular#39826 to account for interpolation
characters inside quotes.

Fixes angular#39601.

packages/compiler/src/expression_parser/parser.ts

@@ -8,7 +8,6 @@
 
 import * as chars from '../chars';
 import {DEFAULT_INTERPOLATION_CONFIG, InterpolationConfig} from '../ml_parser/interpolation_config';
-import {escapeRegExp} from '../util';
 
 import {AbsoluteSourceSpan, AST, AstVisitor, ASTWithSource, Binary, BindingPipe, Chain, Conditional, EmptyExpr, ExpressionBinding, FunctionCall, ImplicitReceiver, Interpolation, KeyedRead, KeyedWrite, LiteralArray, LiteralMap, LiteralMapKey, LiteralPrimitive, MethodCall, NonNullAssert, ParserError, ParseSpan, PrefixNot, PropertyRead, PropertyWrite, Quote, RecursiveAstVisitor, SafeMethodCall, SafePropertyRead, TemplateBinding, TemplateBindingIdentifier, ThisReceiver, Unary, VariableBinding} from './ast';
 import {EOF, isIdentifier, isQuote, Lexer, Token, TokenType} from './lexer';
@@ -30,20 +29,6 @@ export class TemplateBindingParseResult {
       public errors: ParserError[]) {}
 }
 
-const defaultInterpolateRegExp = _createInterpolateRegExp(DEFAULT_INTERPOLATION_CONFIG);
-function _getInterpolateRegExp(config: InterpolationConfig): RegExp {
-  if (config === DEFAULT_INTERPOLATION_CONFIG) {
-    return defaultInterpolateRegExp;
-  } else {
-    return _createInterpolateRegExp(config);
-  }
-}
-
-function _createInterpolateRegExp(config: InterpolationConfig): RegExp {
-  const pattern = escapeRegExp(config.start) + '([\\s\\S]*?)' + escapeRegExp(config.end);
-  return new RegExp(pattern, 'g');
-}
-
 export class Parser {
   private errors: ParserError[] = [];
 
@@ -247,7 +232,7 @@ export class Parser {
         // parse from starting {{ to ending }} while ignoring content inside quotes.
         const fullStart = i;
         const exprStart = fullStart + interpStart.length;
-        const exprEnd = this._getExpressiondEndIndex(input, interpEnd, exprStart);
+        const exprEnd = this._getInterpolationEndIndex(input, interpEnd, exprStart);
         if (exprEnd === -1) {
           // Could not find the end of the interpolation; do not parse an expression.
           // Instead we should extend the content on the last raw string.
@@ -315,59 +300,76 @@ export class Parser {
     return null;
   }
 
-  private _checkNoInterpolation(
-      input: string, location: string, interpolationConfig: InterpolationConfig): void {
-    const regexp = _getInterpolateRegExp(interpolationConfig);
-    const parts = input.split(regexp);
-    if (parts.length > 1) {
+  private _checkNoInterpolation(input: string, location: string, {start, end}: InterpolationConfig):
+      void {
+    let startIndex = -1;
+    let endIndex = -1;
+
+    this._forEachUnquotedChar(input, 0, charIndex => {
+      if (startIndex === -1) {
+        startIndex = input.indexOf(start, charIndex);
+        return false;
+      } else {
+        endIndex = this._getInterpolationEndIndex(input, end, charIndex);
+        return endIndex > -1;
+      }
+    });
+
+    if (startIndex > -1 && endIndex > -1) {
       this._reportError(
-          `Got interpolation (${interpolationConfig.start}${
-              interpolationConfig.end}) where expression was expected`,
-          input,
-          `at column ${this._findInterpolationErrorColumn(parts, 1, interpolationConfig)} in`,
-          location);
+          `Got interpolation (${start}${end}) where expression was expected`, input,
+          `at column ${startIndex} in`, location);
     }
   }
 
-  private _findInterpolationErrorColumn(
-      parts: string[], partInErrIdx: number, interpolationConfig: InterpolationConfig): number {
-    let errLocation = '';
-    for (let j = 0; j < partInErrIdx; j++) {
-      errLocation += j % 2 === 0 ?
-          parts[j] :
-          `${interpolationConfig.start}${parts[j]}${interpolationConfig.end}`;
-    }
+  /**
+   * Finds the index of the end of an interpolation expression
+   * while ignoring comments and quoted content.
+   */
+  private _getInterpolationEndIndex(input: string, expressionEnd: string, start: number): number {
+    let result = -1;
+
+    this._forEachUnquotedChar(input, start, charIndex => {
+      if (input.startsWith(expressionEnd, charIndex)) {
+        result = charIndex;
+        return true;
+      }
+      // Nothing else in the expression matters after we've
+      // hit a comment so look directly for the end token.
+      if (input.startsWith('//', charIndex)) {
+        result = input.indexOf(expressionEnd, charIndex);
+        return true;
+      }
+      return false;
+    });
 
-    return errLocation.length;
+    return result;
   }
 
   /**
-   * Finds the index of the end of an interpolation expression
-   * while ignoring comments and quoted content.
+   * Invokes a callback function for each character of a string that is outside
+   * of a quote.
+   * @param input String to loop through.
+   * @param start Index within the string at which to start.
+   * @param callback Callback to be invoked for each index. If the callback
+   *     returns `true`, the loop will be broken off.
    */
-  private _getExpressiondEndIndex(input: string, expressionEnd: string, start: number): number {
+  private _forEachUnquotedChar(input: string, start: number, callback: (index: number) => boolean):
+      void {
     let currentQuote: string|null = null;
     let escapeCount = 0;
     for (let i = start; i < input.length; i++) {
       const char = input[i];
-      // Skip the characters inside quotes. Note that we only care about the
-      // outer-most quotes matching up and we need to account for escape characters.
+      // Skip the characters inside quotes. Note that we only care about the outer-most
+      // quotes matching up and we need to account for escape characters.
       if (isQuote(input.charCodeAt(i)) && (currentQuote === null || currentQuote === char) &&
           escapeCount % 2 === 0) {
         currentQuote = currentQuote === null ? char : null;
-      } else if (currentQuote === null) {
-        if (input.startsWith(expressionEnd, i)) {
-          return i;
-        }
-        // Nothing else in the expression matters after we've
-        // hit a comment so look directly for the end token.
-        if (input.startsWith('//', i)) {
-          return input.indexOf(expressionEnd, i);
-        }
+      } else if (currentQuote === null && callback(i)) {
+        break;
       }
       escapeCount = char === '\\' ? escapeCount + 1 : 0;
     }
-    return -1;
   }
 }
 

packages/compiler/test/expression_parser/parser_spec.ts

@@ -314,6 +314,10 @@ describe('parser', () => {
     it('should report when encountering interpolation', () => {
       expectActionError('{{a()}}', 'Got interpolation ({{}}) where expression was expected');
     });
+
+    it('should not report interpolation inside a string', () => {
+      expect(parseAction('"{{a()}}"').errors).toEqual([]);
+    });
   });
 
   describe('parse spans', () => {
@@ -486,6 +490,10 @@ describe('parser', () => {
       expectBindingError('{{a.b}}', 'Got interpolation ({{}}) where expression was expected');
     });
 
+    it('should not report interpolation inside a string', () => {
+      expect(parseBinding('"{{exp}}"').errors).toEqual([]);
+    });
+
     it('should parse conditional expression', () => {
       checkBinding('a < b ? a : b');
     });
@@ -952,6 +960,10 @@ describe('parser', () => {
           'Got interpolation ({{}}) where expression was expected');
     });
 
+    it('should not report interpolation inside a string', () => {
+      expect(parseSimpleBinding('"{{exp}}"').errors).toEqual([]);
+    });
+
     it('should report when encountering field write', () => {
       expectError(validate(parseSimpleBinding('a = b')), 'Bindings cannot contain assignments');
     });

packages/core/test/acceptance/property_binding_spec.ts

@@ -623,4 +623,15 @@ describe('property bindings', () => {
          fixture.detectChanges();
        }).not.toThrow();
      });
+
+  it('should allow quoted binding syntax inside property binding', () => {
+    @Component({template: `<span [id]="'{{ id }}'"></span>`})
+    class Comp {
+    }
+
+    TestBed.configureTestingModule({declarations: [Comp]});
+    const fixture = TestBed.createComponent(Comp);
+    fixture.detectChanges();
+    expect(fixture.nativeElement.querySelector('span').id).toBe('{{ id }}');
+  });
 });