port isDateTime placeholder from XMLUnit.NET, addresses #174

RELEASE_NOTES.md

@@ -20,6 +20,12 @@ element/attribute. This allows placeholders like
   PR [#178](https://github.com/xmlunit/xmlunit/issues/178) by
   [@Jazzyekim](https://github.com/Jazzyekim).
 
+* add a new `${xmlunit.isDateTime}` placeholder
+  inspired by [#xmlunit.net/31](https://github.com/xmlunit/xmlunit.net/pull/31) and
+  [#xmlunit.net/32](https://github.com/xmlunit/xmlunit.net/pull/32) by
+  [MilkyWare](https://github.com/MilkyWare)
+  Issue [#174](https://github.com/xmlunit/xmlunit/issues/174)
+
 ## XMLUnit for Java 2.6.4 - /Released 2020-03-08/
 
 * the dependencies on JAXB implementation and its transitive

xmlunit-placeholders/src/main/java/org/xmlunit/placeholder/IsDateTimePlaceholderHandler.java

@@ -0,0 +1,83 @@
+/*
+  This file is licensed to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+package org.xmlunit.placeholder;
+
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import org.xmlunit.diff.ComparisonResult;
+
+/**
+ * Handler for the {@code isDateTime} placeholder keyword.
+ * @since 2.7.0
+ */
+public class IsDateTimePlaceholderHandler implements PlaceholderHandler {
+    private static final String PLACEHOLDER_NAME = "isDateTime";
+
+    private static final List<String> ISO_PATTERNS = Collections.unmodifiableList(Arrays.asList(
+        "yyyy-MM-dd",
+        "yyyy-MM-dd'T'HH:mm:ss",
+        "yyyy-MM-dd'T'HH:mm:ss.SSS",
+        "yyyy-MM-dd'T'HH:mm:ssZ",
+        "yyyy-MM-dd'T'HH:mm:ss.SSSZ",
+        "yyyy-MM-dd'T'HH:mm:ssXXX",
+        "yyyy-MM-dd'T'HH:mm:ss.SSSXXX",
+        "yyyy-MM-dd HH:mm:ss",
+        "yyyy-MM-dd HH:mm:ss.SSS",
+        "yyyy-MM-dd HH:mm:ssZ",
+        "yyyy-MM-dd HH:mm:ss.SSSZ",
+        "yyyy-MM-dd HH:mm:ssXXX",
+        "yyyy-MM-dd HH:mm:ss.SSSXXX"
+     ));
+
+    @Override
+    public String getKeyword() {
+        return PLACEHOLDER_NAME;
+    }
+
+    @Override
+    public ComparisonResult evaluate(final String testText, final String... param) {
+        return canParse(testText)
+            ? ComparisonResult.EQUAL
+            : ComparisonResult.DIFFERENT;
+    }
+
+    private boolean canParse(final String testText) {
+        if (testText == null || "".equals(testText)) {
+            return false;
+        }
+        if (canParse(DateFormat.getDateInstance(DateFormat.SHORT), testText) ||
+            canParse(DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.SHORT), testText)) {
+            return true;
+        }
+        for (final String pattern : ISO_PATTERNS) {
+            if (canParse(new SimpleDateFormat(pattern), testText)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private boolean canParse(final DateFormat fmt, final String testText) {
+        try {
+            return null != fmt.parse(testText);
+        } catch (ParseException ex) {
+            return false;
+        }
+    }
+}

xmlunit-placeholders/src/main/resources/META-INF/services/org.xmlunit.placeholder.PlaceholderHandler

@@ -1,3 +1,4 @@
 org.xmlunit.placeholder.IgnorePlaceholderHandler
 org.xmlunit.placeholder.IsNumberPlaceholderHandler
-org.xmlunit.placeholder.MatchesRegexPlaceholderHandler
+org.xmlunit.placeholder.MatchesRegexPlaceholderHandler
+org.xmlunit.placeholder.IsDateTimePlaceholderHandler

xmlunit-placeholders/src/test/java/org/xmlunit/placeholder/IsDateTimePlaceholderHandlerTest.java

@@ -0,0 +1,68 @@
+/*
+  This file is licensed to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+package org.xmlunit.placeholder;
+
+import java.util.Locale;
+
+import org.junit.Test;
+import org.xmlunit.diff.ComparisonResult;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.junit.Assert.assertThat;
+
+public class IsDateTimePlaceholderHandlerTest {
+
+    private PlaceholderHandler placeholderHandler = new IsDateTimePlaceholderHandler();
+
+    @Test
+    public void shouldGetKeyword() {
+        String expected = "isDateTime";
+        String keyword = placeholderHandler.getKeyword();
+
+        assertThat(keyword, equalTo(expected));
+    }
+
+    @Test
+    public void shouldAcceptABunchOfStrings() {
+        final Locale l = Locale.getDefault();
+        try {
+            Locale.setDefault(Locale.US);
+            for (final String s : new String[] {
+                    "2020-01-01",
+                    "01/01/2020",
+                    "01/01/2020",
+                    "2020-01-01T15:00",
+                    "2020-01-01 15:00:00Z",
+                    "01/01/2020 15:00",
+                }) {
+                final ComparisonResult comparisonResult = placeholderHandler.evaluate(s);
+                assertThat(comparisonResult, equalTo(ComparisonResult.EQUAL));
+            }
+        } finally {
+            Locale.setDefault(l);
+        }
+    }
+
+    @Test
+    public void shouldRejectNullAndEmpty() {
+        assertThat(placeholderHandler.evaluate(null), equalTo(ComparisonResult.DIFFERENT));
+        assertThat(placeholderHandler.evaluate(""), equalTo(ComparisonResult.DIFFERENT));
+    }
+
+    @Test
+    public void shouldRejectExtraContent() {
+        assertThat(placeholderHandler.evaluate("This is a test date 2020-01-01"),
+                   equalTo(ComparisonResult.DIFFERENT));
+    }
+}

xmlunit-placeholders/src/test/java/org/xmlunit/placeholder/PlaceholderDifferenceEvaluatorTest.java

@@ -415,4 +415,40 @@ public void hasMalformedPlaceholder_Attribute() {
 
         assertTrue(diff.hasDifferences());
     }
+
+    @Test
+    public void isDateTimePlaceholder_Attribute_NotDateTime() {
+        String control = "<elem1 attr='${xmlunit.isDateTime}'/>";
+        String test = "<elem1 attr='abc'/>";
+        Diff diff = PlaceholderSupport.withPlaceholderSupport(DiffBuilder.compare(control).withTest(test)).build();
+
+        assertTrue(diff.hasDifferences());
+    }
+
+    @Test
+    public void isDateTimePlaceholder_Attribute_IsDateTime() {
+        String control = "<elem1 attr='${xmlunit.isDateTime}'/>";
+        String test = "<elem1 attr='2020-01-01 15:00:00Z'/>";
+        Diff diff = PlaceholderSupport.withPlaceholderSupport(DiffBuilder.compare(control).withTest(test)).build();
+
+        assertFalse(diff.hasDifferences());
+    }
+
+    @Test
+    public void isDateTimePlaceholder_Element_NotDateTime() {
+        String control = "<elem1>${xmlunit.isDateTime}</elem1>";
+        String test = "<elem1>abc</elem1>";
+        Diff diff = PlaceholderSupport.withPlaceholderSupport(DiffBuilder.compare(control).withTest(test)).build();
+
+        assertTrue(diff.hasDifferences());
+    }
+
+    @Test
+    public void isDateTimePlaceholder_Element_IsDateTime() {
+        String control = "<elem1>${xmlunit.isDateTime}</elem1>";
+        String test = "<elem1>2020-01-01 15:00:00Z</elem1>";
+        Diff diff = PlaceholderSupport.withPlaceholderSupport(DiffBuilder.compare(control).withTest(test)).build();
+
+        assertFalse(diff.hasDifferences());
+    }
 }