Add Combined renderer option: mergeThreshold

this option is currently only for the Combined renderer.
it determines whether a replace-type block should be merged or not
depending on the content changed ratio, which values between 0 and 1.

Signed-off-by: Jack Cherng <jfcherng@gmail.com>

Author: jfcherng

README.md

@@ -100,6 +100,10 @@ $rendererOptions = [
     'spacesToNbsp' => false,
     // HTML renderer tab width (negative = do not convert into spaces)
     'tabSize' => 4,
+    // this option is currently only for the Combined renderer.
+    // it determines whether a replace-type block should be merged or not
+    // depending on the content changed ratio, which values between 0 and 1.
+    'mergeThreshold' => 0.8,
     // this option is currently only for the Json renderer.
     // 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.

example/demo.php

@@ -68,6 +68,10 @@
             'spacesToNbsp' => false,
             // HTML renderer tab width (negative = do not convert into spaces)
             'tabSize' => 4,
+            // this option is currently only for the Combined renderer.
+            // it determines whether a replace-type block should be merged or not
+            // depending on the content changed ratio, which values between 0 and 1.
+            'mergeThreshold' => 0.8,
             // this option is currently only for the Json renderer.
             // 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.

src/Renderer/AbstractRenderer.php

@@ -39,15 +39,19 @@ abstract class AbstractRenderer implements RendererInterface
         // renderer language: eng, cht, chs, jpn, ...
         // or an array which has the same keys with a language file
         'language' => 'eng',
-        // HTML renderer tab width (negative = do not convert into spaces)
-        'tabSize' => 4,
-        // show a separator between different diff hunks in HTML renderers
-        'separateBlock' => true,
         // show line numbers in HTML renderers
         'lineNumbers' => true,
+        // show a separator between different diff hunks in HTML renderers
+        'separateBlock' => true,
         // the frontend HTML could use CSS "white-space: pre;" to visualize consecutive whitespaces
         // but if you want to visualize them in the backend with " ", you can set this to true
         'spacesToNbsp' => false,
+        // HTML renderer tab width (negative = do not convert into spaces)
+        'tabSize' => 4,
+        // this option is currently only for the Combined renderer.
+        // it determines whether a replace-type block should be merged or not
+        // depending on the content changed ratio, which values between 0 and 1.
+        'mergeThreshold' => 0.8,
         // this option is currently only for the Json renderer.
         // 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.

src/Renderer/Html/Combined.php

@@ -409,7 +409,7 @@ protected function isLinesMergeable(string $oldLine, string $newLine, string $cl
         /** @var float the changed ratio, 0 <= range < 1 */
         $changedRatio = ($sumLength - (\strlen($cleanLine) << 1)) / ($sumLength + 1);
 
-        return $changedRatio < 0.8;
+        return $changedRatio <= $this->options['mergeThreshold'];
     }
 
     /**