Merge pull request #14 from jfcherng/add-renderer-option-resultForIdenticals

Add renderer option: resultForIdenticals

Author: jfcherng

README.md

@@ -92,6 +92,9 @@ $rendererOptions = [
     // internally, ops (tags) are all int type but this is not good for human reading.
     // set this to "true" to convert them into string form before outputting.
     'outputTagAsString' => true,
+    // change this value to a non-null one as the the returned diff
+    // if the two input strings are identical
+    'resultForIdenticals' => null,
     // extra HTML classes added to the DOM of the diff container
     'wrapperClasses' => ['diff-wrapper'],
 ];

example/demo.php

@@ -48,6 +48,9 @@
             // internally, ops (tags) are all int type but this is not good for human reading.
             // set this to "true" to convert them into string form before outputting.
             'outputTagAsString' => false,
+            // change this value to a non-null one as the the returned diff
+            // if the two input strings are identical
+            'resultForIdenticals' => null,
             // extra HTML classes added to the DOM of the diff container
             'wrapperClasses' => ['diff-wrapper'],
         ];

src/Renderer/AbstractRenderer.php

@@ -49,6 +49,9 @@ abstract class AbstractRenderer implements RendererInterface
         // internally, ops (tags) are all int type but this is not good for human reading.
         // set this to "true" to convert them into string form before outputting.
         'outputTagAsString' => false,
+        // change this value to a non-null one as the the returned diff
+        // if the two input strings are identical
+        'resultForIdenticals' => null,
         // extra HTML classes added to the DOM of the diff container
         'wrapperClasses' => ['diff-wrapper'],
     ];
@@ -104,12 +107,23 @@ public function getOptions(): array
 
     /**
      * {@inheritdoc}
+     *
+     * @final
+     *
+     * @todo mark this method with "final" in the next major release
      */
     public function getResultForIdenticals(): string
     {
-        return '';
+        return $this->options['resultForIdenticals'] ?? $this->getResultForIdenticalsDefault();
     }
 
+    /**
+     * Get the renderer default result when the old and the new are the same.
+     *
+     * @return string
+     */
+    abstract public function getResultForIdenticalsDefault(): string;
+
     /**
      * {@inheritdoc}
      */

src/Renderer/Html/AbstractHtml.php

@@ -32,6 +32,14 @@ abstract class AbstractHtml extends AbstractRenderer
         SequenceMatcher::OP_REP => 'rep',
     ];
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getResultForIdenticalsDefault(): string
+    {
+        return '';
+    }
+
     /**
      * Render and return an array structure suitable for generating HTML
      * based differences. Generally called by subclasses that generate a

src/Renderer/Html/Json.php

@@ -28,7 +28,7 @@ final class Json extends AbstractHtml
     /**
      * {@inheritdoc}
      */
-    public function getResultForIdenticals(): string
+    public function getResultForIdenticalsDefault(): string
     {
         return '[]';
     }

src/Renderer/Text/AbstractText.php

@@ -15,4 +15,12 @@ abstract class AbstractText extends AbstractRenderer
      * @var bool is this renderer pure text?
      */
     const IS_TEXT_RENDERER = true;
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getResultForIdenticalsDefault(): string
+    {
+        return '';
+    }
 }

tests/Renderer/RendererTest.php

@@ -44,4 +44,28 @@ public function testSetOptionsWithLanguageArray(): void
             'Rederer options: "language" array should work.'
         );
     }
+
+    /**
+     * Test the AbstractRenderer::setOptions with result for identicals.
+     *
+     * @covers \Jfcherng\Diff\Renderer\AbstractRenderer::setOptions
+     */
+    public function testSetOptionsWithResultForIdenticals(): void
+    {
+        $testMarker = '_TEST_MARKER_';
+
+        $diffResult = DiffHelper::calculate(
+            'we are the same',
+            'we are the same',
+            'Inline',
+            [],
+            ['resultForIdenticals' => $testMarker]
+        );
+
+        static::assertSame(
+            $testMarker,
+            $diffResult,
+            'Rederer options: result for identicals should work.'
+        );
+    }
 }