See #731 - adds granular control over level 2 optimizations.

Why: * So users can selectively disable certain optimizations if they want to.
clean-css · Jan 10, 2017 · 0b81de2 · 0b81de2
1 parent 47486aa
commit 0b81de2
Show file tree

Hide file tree

Showing 13 changed files with 195 additions and 24 deletions.
diff --git a/History.md b/History.md
@@ -19,6 +19,7 @@
 * Fixed issue [#685](https://github.com/jakubpawlowicz/clean-css/issues/685) - adds lowercasing hex colors optimization.
 * Fixed issue [#686](https://github.com/jakubpawlowicz/clean-css/issues/686) - adds rounding precision for all units.
 * Fixed issue [#703](https://github.com/jakubpawlowicz/clean-css/issues/703) - changes default IE compatibility to 10+.
+* Fixed issue [#731](https://github.com/jakubpawlowicz/clean-css/issues/731) - adds granular control over level 2 optimizations.
 * Fixed issue [#739](https://github.com/jakubpawlowicz/clean-css/issues/739) - error when a closing brace is missing.
 * Fixed issue [#750](https://github.com/jakubpawlowicz/clean-css/issues/750) - allows `width` overriding.
 * Fixed issue [#756](https://github.com/jakubpawlowicz/clean-css/issues/756) - adds disabling font-weight optimizations.

diff --git a/README.md b/README.md
@@ -129,10 +129,16 @@ Level 2 optimizations:
 ```bash
 cleancss -O2 one.css
 cleancss -O2 mediaMerging:off;restructuring:off;semanticMerging:on;shorthandCompacting:off one.css
-# `mediaMerging` controls `@media` merging behavior; defaults to `on` (alias to `true`)
-# `restructuring` controls content restructuring behavior; defaults `off` (alias to `false`)
-# `semanticMerging` controls semantic merging behavior; defaults to `off` (alias to `false`)
-# `shorthandCompacting` controls shorthand compacting behavior; defaults to `on` (alias to `true`)
+# `adjacentRulesMerging` controls adjacent rules merging; defaults to `on`
+# `duplicateFontRulesRemoving` controls duplicate `@font-face` removing; defaults to `on`
+# `duplicateMediaRemoving` controls duplicate `@media` removing; defaults to `on`
+# `duplicateRulesRemoving` controls duplicate rules removing; defaults to `on`
+# `mediaMerging` controls `@media` merging; defaults to `on`
+# `nonAdjacentRulesMerging` controls non-adjacent rule merging; defaults to `on`
+# `nonAdjacentRulesReducing` controls non-adjacent rule reducing; defaults to `on`
+# `restructuring` controls content restructuring; defaults to `off`
+# `semanticMerging` controls semantic merging; defaults to `off`
+# `shorthandCompacting` controls shorthand compacting; defaults to `on`
 ```
 
 ### How to use clean-css API?
@@ -194,10 +200,16 @@ new CleanCSS({
 new CleanCSS({
   level: {
     2: {
-      mediaMerging: true, // controls `@media` merging behavior; defaults to true
-      restructuring: false, // controls content restructuring behavior; defaults to false
-      semanticMerging: false, // controls semantic merging behavior; defaults to false
-      shorthandCompacting: true // controls shorthand compacting behavior; defaults to true
+      adjacentRulesMerging: true, // controls adjacent rules merging; defaults to true
+      duplicateFontRulesRemoving: true, // controls duplicate `@font-face` removing; defaults to true
+      duplicateMediaRemoving: true, // controls duplicate `@media` removing; defaults to true
+      duplicateRulesRemoving: true, // controls duplicate rules removing; defaults to true
+      mediaMerging: true, // controls `@media` merging; defaults to true
+      nonAdjacentRulesMerging: true, // controls non-adjacent rule merging; defaults to true
+      nonAdjacentRulesReducing: true, // controls non-adjacent rule reducing; defaults to true
+      restructuring: false, // controls content restructuring; defaults to false
+      semanticMerging: false, // controls semantic merging; defaults to false
+      shorthandCompacting: true, // controls shorthand compacting; defaults to true
     }
   }
 });

diff --git a/bin/cleancss b/bin/cleancss
@@ -45,10 +45,16 @@ commands.on('--help', function () {
   console.log('  Level 2 optimizations:');
   console.log('    %> cleancss -O2 one.css');
   console.log('    %> cleancss -O2 mediaMerging:off;restructuring:off;semanticMerging:on;shorthandCompacting:off one.css');
-  console.log('    %> # `mediaMerging` controls `@media` merging behavior; defaults to `on` (alias to `true`)');
-  console.log('    %> # `restructuring` controls content restructuring behavior; defaults to `off` (alias to `false`)');
-  console.log('    %> # `semanticMerging` controls semantic merging behavior; defaults to `off` (alias to `false`)');
-  console.log('    %> # `shorthandCompacting` controls shorthand compacting behavior; defaults to `on` (alias to `true`)');
+  console.log('    %> # `adjacentRulesMerging` controls adjacent rules merging; defaults to `on`');
+  console.log('    %> # `duplicateFontRulesRemoving` controls duplicate `@font-face` removing; defaults to `on`');
+  console.log('    %> # `duplicateMediaRemoving` controls duplicate `@media` removing; defaults to `on`');
+  console.log('    %> # `duplicateRulesRemoving` controls duplicate rules removing; defaults to `on`');
+  console.log('    %> # `mediaMerging` controls `@media` merging; defaults to `on`');
+  console.log('    %> # `nonAdjacentRulesMerging` controls non-adjacent rule merging; defaults to `on`');
+  console.log('    %> # `nonAdjacentRulesReducing` controls non-adjacent rule reducing; defaults to `on`');
+  console.log('    %> # `restructuring` controls content restructuring; defaults to `off`');
+  console.log('    %> # `semanticMerging` controls semantic merging; defaults to `off`');
+  console.log('    %> # `shorthandCompacting` controls shorthand compacting; defaults to `on`');
 
   process.exit();
 });

diff --git a/lib/optimizer/level-2/optimize.js b/lib/optimizer/level-2/optimize.js
@@ -65,27 +65,53 @@ function recursivelyOptimizeProperties(tokens, context) {
 }
 
 function level2Optimize(tokens, context, withRestructuring) {
+  var levelOptions = context.options.level[OptimizationLevel.Two];
+  var reduced;
+  var i;
+
   recursivelyOptimizeBlocks(tokens, context);
   recursivelyOptimizeProperties(tokens, context);
 
-  removeDuplicates(tokens, context);
-  mergeAdjacent(tokens, context);
-  reduceNonAdjacent(tokens, context);
+  if (levelOptions.duplicateRulesRemoving) {
+    removeDuplicates(tokens, context);
+  }
+
+  if (levelOptions.adjacentRulesMerging) {
+    mergeAdjacent(tokens, context);
+  }
+
+  if (levelOptions.nonAdjacentRulesReducing) {
+    reduceNonAdjacent(tokens, context);
+  }
+
+  if (levelOptions.nonAdjacentRulesMerging && levelOptions.nonAdjacentRulesMerging != 'body') {
+    mergeNonAdjacentBySelector(tokens, context);
+  }
 
-  mergeNonAdjacentBySelector(tokens, context);
-  mergeNonAdjacentByBody(tokens, context);
+  if (levelOptions.nonAdjacentRulesMerging && levelOptions.nonAdjacentRulesMerging != 'selector') {
+    mergeNonAdjacentByBody(tokens, context);
+  }
 
-  if (context.options.level[OptimizationLevel.Two].restructuring && withRestructuring) {
+  if (levelOptions.restructuring && levelOptions.adjacentRulesMerging && withRestructuring) {
     restructure(tokens, context);
     mergeAdjacent(tokens, context);
   }
 
-  removeDuplicateFontAtRules(tokens, context);
+  if (levelOptions.restructuring && !levelOptions.adjacentRulesMerging && withRestructuring) {
+    restructure(tokens, context);
+  }
+
+  if (levelOptions.duplicateFontRulesRemoving) {
+    removeDuplicateFontAtRules(tokens, context);
+  }
 
-  if (context.options.level[OptimizationLevel.Two].mediaMerging) {
+  if (levelOptions.duplicateMediaRemoving) {
     removeDuplicateMediaQueries(tokens, context);
-    var reduced = mergeMediaQueries(tokens, context);
-    for (var i = reduced.length - 1; i >= 0; i--) {
+  }
+
+  if (levelOptions.mediaMerging) {
+    reduced = mergeMediaQueries(tokens, context);
+    for (i = reduced.length - 1; i >= 0; i--) {
       level2Optimize(reduced[i][2], context, false);
     }
   }

diff --git a/lib/options/optimization-level.js b/lib/options/optimization-level.js
@@ -15,7 +15,13 @@ DEFAULTS[OptimizationLevel.One] = {
   specialComments: 'all'
 };
 DEFAULTS[OptimizationLevel.Two] = {
+  adjacentRulesMerging: true,
+  duplicateFontRulesRemoving: true,
+  duplicateMediaRemoving: true,
+  duplicateRulesRemoving: true,
   mediaMerging: true,
+  nonAdjacentRulesMerging: true,
+  nonAdjacentRulesReducing: true,
   restructuring: false,
   semanticMerging: false,
   shorthandCompacting: true

diff --git a/test/optimizer/level-2/merge-adjacent-test.js b/test/optimizer/level-2/merge-adjacent-test.js
@@ -98,6 +98,14 @@ vows.describe('remove duplicates')
       ],
     }, { level: { 2: { restructuring: true } } })
   )
+  .addBatch(
+    optimizerContext('with level 2 off but only adjacentRuleMerging on', {
+      'same context': [
+        'a{background:url(image.png)}a{display:block;width:75px;background-repeat:no-repeat}',
+        'a{background:url(image.png);display:block;width:75px;background-repeat:no-repeat}',
+      ],
+    }, { level: { 2: { all: false, adjacentRulesMerging: true } } })
+  )
   .addBatch(
     optimizerContext('with level 2 off', {
       'same context': [

diff --git a/test/optimizer/level-2/merge-non-adjacent-by-body-test.js b/test/optimizer/level-2/merge-non-adjacent-by-body-test.js
@@ -34,6 +34,22 @@ vows.describe('merge non djacent by body')
       ]
     }, { level: 2 })
   )
+  .addBatch(
+    optimizerContext('with level 2 off but nonAdjacentRulesMerging on', {
+      'of element selectors': [
+        'p{color:red}div{display:block}span{color:red}',
+        'p,span{color:red}div{display:block}'
+      ]
+    }, { level: { 2: { all: false, nonAdjacentRulesMerging: true } } })
+  )
+  .addBatch(
+    optimizerContext('with level 2 off but nonAdjacentRulesMerging set to selector', {
+      'of element selectors': [
+        'p{color:red}div{display:block}span{color:red}',
+        'p{color:red}div{display:block}span{color:red}'
+      ]
+    }, { level: { 2: { all: false, nonAdjacentRulesMerging: 'selector' } } })
+  )
   .addBatch(
     optimizerContext('with level 2 off', {
       'with repeated selectors': [

diff --git a/test/optimizer/level-2/merge-non-adjacent-by-selector-test.js b/test/optimizer/level-2/merge-non-adjacent-by-selector-test.js
@@ -18,6 +18,22 @@ vows.describe('merge non djacent by selector')
       // ]
     }, { level: 2 })
   )
+  .addBatch(
+    optimizerContext('with level 2 off but nonAdjacentRulesMerging on', {
+      'of element selectors': [
+        '.one{color:red}.two{color:#fff}.one{font-weight:400}',
+        '.one{color:red;font-weight:400}.two{color:#fff}'
+      ]
+    }, { level: { 2: { all: false, nonAdjacentRulesMerging: true } } })
+  )
+  .addBatch(
+    optimizerContext('with level 2 off but nonAdjacentRulesMerging set to body', {
+      'of element selectors': [
+        '.one{color:red}.two{color:#fff}.one{font-weight:400}',
+        '.one{color:red}.two{color:#fff}.one{font-weight:400}'
+      ]
+    }, { level: { 2: { all: false, nonAdjacentRulesMerging: 'body' } } })
+  )
   .addBatch(
     optimizerContext('level 2 off', {
       'up': [

diff --git a/test/optimizer/level-2/reduce-non-adjacent-test.js b/test/optimizer/level-2/reduce-non-adjacent-test.js
@@ -126,6 +126,14 @@ vows.describe('remove duplicates')
       ]
     }, { aggressiveMerging: false, level: { 2: { restructuring: true } } })
   )
+  .addBatch(
+    optimizerContext('level 2 off but nonAdjacentRulesReducing on', {
+      'non-adjacent with multi selectors': [
+        'a{padding:10px;margin:0;color:red}.one{color:red}a,p{color:red;padding:0}',
+        'a{margin:0;color:red}.one{color:red}a,p{color:red;padding:0}'
+      ]
+    }, { level: { 2: { all: false, nonAdjacentRulesReducing: true } } })
+  )
   .addBatch(
     optimizerContext('level 2 off', {
       'non-adjacent': [

diff --git a/test/optimizer/level-2/remove-duplicate-font-at-rules-test.js b/test/optimizer/level-2/remove-duplicate-font-at-rules-test.js
@@ -18,6 +18,14 @@ vows.describe('remove duplicate @font-face at-rules')
       ]
     }, { level: 2 })
   )
+  .addBatch(
+    optimizerContext('level 2 off but duplicateFontRulesRemoving on', {
+      'non-adjacent': [
+        '@font-face{font-family:test;src:url(fonts/test.woff2)}.one{color:red}@font-face{font-family:test;src:url(fonts/test.woff2)}',
+        '@font-face{font-family:test;src:url(fonts/test.woff2)}.one{color:red}'
+      ]
+    }, { level: { 2: { all: false, duplicateFontRulesRemoving: true } } })
+  )
   .addBatch(
     optimizerContext('level 2 off', {
       'keeps content same': [

diff --git a/test/optimizer/level-2/remove-duplicate-media-queries-test.js b/test/optimizer/level-2/remove-duplicate-media-queries-test.js
@@ -22,6 +22,14 @@ vows.describe('remove duplicate media queries')
       ]
     }, { level: 2 })
   )
+  .addBatch(
+    optimizerContext('level 2 off but duplicateMediaRemoving on', {
+      'non-adjacent': [
+        '@media screen{a{color:red}}@media print{a{color:#fff}}@media screen{a{color:red}}',
+        '@media print{a{color:#fff}}@media screen{a{color:red}}'
+      ]
+    }, { level: { 2: { all: false, duplicateMediaRemoving: true } } })
+  )
   .addBatch(
     optimizerContext('level 2 off', {
       'keeps content same': [
@@ -33,8 +41,8 @@ vows.describe('remove duplicate media queries')
   .addBatch(
     optimizerContext('media merging off', {
       'keeps content same': [
-        '@media screen{a{color:red}}@media screen{a{color:red}}',
-        '@media screen{a{color:red}}@media screen{a{color:red}}'
+        '@media screen{a{color:red}}@media screen{div{color:red}}',
+        '@media screen{a{color:red}}@media screen{div{color:red}}'
       ]
     }, { level: { 2: { mediaMerging: false } } })
   )

diff --git a/test/optimizer/level-2/remove-duplicates-test.js b/test/optimizer/level-2/remove-duplicates-test.js
@@ -42,6 +42,14 @@ vows.describe('remove duplicates')
       ]
     }, { level: 2 })
   )
+  .addBatch(
+    optimizerContext('level 2 off but removing duplicates on', {
+      'same context': [
+        'a{color:red}div{color:blue}a{color:red}',
+        'div{color:#00f}a{color:red}'
+      ]
+    }, { level: { 2: { all: false, duplicateRulesRemoving: true } } })
+  )
   .addBatch(
     optimizerContext('level 2 off', {
       'same context': [

diff --git a/test/options/optimization-level-test.js b/test/options/optimization-level-test.js
@@ -70,7 +70,13 @@ vows.describe(optimizationLevelFrom)
       },
       'has level 2 options': function (levelOptions) {
         assert.deepEqual(levelOptions['2'], {
+          adjacentRulesMerging: true,
+          duplicateFontRulesRemoving: true,
+          duplicateMediaRemoving: true,
+          duplicateRulesRemoving: true,
           mediaMerging: true,
+          nonAdjacentRulesMerging: true,
+          nonAdjacentRulesReducing: true,
           restructuring: false,
           semanticMerging: false,
           shorthandCompacting: true
@@ -106,7 +112,13 @@ vows.describe(optimizationLevelFrom)
       },
       'has level 2 options': function (levelOptions) {
         assert.deepEqual(levelOptions['2'], {
+          adjacentRulesMerging: true,
+          duplicateFontRulesRemoving: true,
+          duplicateMediaRemoving: true,
+          duplicateRulesRemoving: true,
           mediaMerging: true,
+          nonAdjacentRulesMerging: true,
+          nonAdjacentRulesReducing: true,
           restructuring: false,
           semanticMerging: false,
           shorthandCompacting: true
@@ -131,7 +143,13 @@ vows.describe(optimizationLevelFrom)
       },
       'has level 2 options': function (levelOptions) {
         assert.deepEqual(levelOptions['2'], {
+          adjacentRulesMerging: false,
+          duplicateFontRulesRemoving: false,
+          duplicateMediaRemoving: false,
+          duplicateRulesRemoving: false,
           mediaMerging: true,
+          nonAdjacentRulesMerging: false,
+          nonAdjacentRulesReducing: false,
           restructuring: false,
           semanticMerging: false,
           shorthandCompacting: false
@@ -156,7 +174,13 @@ vows.describe(optimizationLevelFrom)
       },
       'has level 2 options': function (levelOptions) {
         assert.deepEqual(levelOptions['2'], {
+          adjacentRulesMerging: false,
+          duplicateFontRulesRemoving: false,
+          duplicateMediaRemoving: false,
+          duplicateRulesRemoving: false,
           mediaMerging: true,
+          nonAdjacentRulesMerging: false,
+          nonAdjacentRulesReducing: false,
           restructuring: false,
           semanticMerging: false,
           shorthandCompacting: false
@@ -198,7 +222,13 @@ vows.describe(optimizationLevelFrom)
       },
       'has level 2 options': function (levelOptions) {
         assert.deepEqual(levelOptions['2'], {
+          adjacentRulesMerging: true,
+          duplicateFontRulesRemoving: true,
+          duplicateMediaRemoving: true,
+          duplicateRulesRemoving: true,
           mediaMerging: false,
+          nonAdjacentRulesMerging: true,
+          nonAdjacentRulesReducing: true,
           restructuring: false,
           semanticMerging: true,
           shorthandCompacting: true
@@ -223,7 +253,13 @@ vows.describe(optimizationLevelFrom)
       },
       'has level 2 options': function (levelOptions) {
         assert.deepEqual(levelOptions['2'], {
+          adjacentRulesMerging: true,
+          duplicateFontRulesRemoving: true,
+          duplicateMediaRemoving: true,
+          duplicateRulesRemoving: true,
           mediaMerging: false,
+          nonAdjacentRulesMerging: true,
+          nonAdjacentRulesReducing: true,
           restructuring: false,
           semanticMerging: true,
           shorthandCompacting: true
@@ -248,7 +284,13 @@ vows.describe(optimizationLevelFrom)
       },
       'has level 2 options': function (levelOptions) {
         assert.deepEqual(levelOptions['2'], {
+          adjacentRulesMerging: false,
+          duplicateFontRulesRemoving: false,
+          duplicateMediaRemoving: false,
+          duplicateRulesRemoving: false,
           mediaMerging: true,
+          nonAdjacentRulesMerging: false,
+          nonAdjacentRulesReducing: false,
           restructuring: false,
           semanticMerging: true,
           shorthandCompacting: false
@@ -273,7 +315,13 @@ vows.describe(optimizationLevelFrom)
       },
       'has level 2 options': function (levelOptions) {
         assert.deepEqual(levelOptions['2'], {
+          adjacentRulesMerging: false,
+          duplicateFontRulesRemoving: false,
+          duplicateMediaRemoving: false,
+          duplicateRulesRemoving: false,
           mediaMerging: true,
+          nonAdjacentRulesMerging: false,
+          nonAdjacentRulesReducing: false,
           restructuring: false,
           semanticMerging: true,
           shorthandCompacting: false