fix(postcss-merge-longhand): add revert to unmergeable values (#1211)

Fix #1204
cssnano · Oct 19, 2021 · b67cdc4 · b67cdc4
1 parent bb0a76a
commit b67cdc4
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Showing 2 changed files with 15 additions and 12 deletions.
diff --git a/packages/postcss-merge-longhand/src/__tests__/boxBase.js b/packages/postcss-merge-longhand/src/__tests__/boxBase.js
@@ -321,6 +321,11 @@ addTests(
       'h1{box-bottom:INHERIT;box-top:INHERIT;box-left:INHERIT;box-right:INHERIT}',
     expected: 'h1{box:INHERIT}',
   },
+  {
+    message: 'should not merge box props when one has a revert property',
+    fixture: 'h1{box:10px;box-left:revert}',
+    expected: (prop) => `h1{${prop.toLowerCase()}:10px;${prop}-left:revert}`,
+  },
   {
     message: 'should handle empty box properties',
     fixture: 'h1{box:;}',

diff --git a/packages/postcss-merge-longhand/src/lib/canMerge.js b/packages/postcss-merge-longhand/src/lib/canMerge.js
@@ -3,21 +3,19 @@ import isCustomProp from './isCustomProp';
 const important = (node) => node.important;
 const unimportant = (node) => !node.important;
 
-const hasInherit = (node) => node.value.toLowerCase() === 'inherit';
-const hasInitial = (node) => node.value.toLowerCase() === 'initial';
-const hasUnset = (node) => node.value.toLowerCase() === 'unset';
+/* Cannot be combined with other values in shorthand 
+  https://www.w3.org/TR/css-cascade-5/#shorthand */
+const cssWideKeywords = ['inherit', 'initial', 'unset', 'revert'];
 
 export default (props, includeCustomProps = true) => {
-  if (props.some(hasInherit) && !props.every(hasInherit)) {
-    return false;
-  }
-
-  if (props.some(hasInitial) && !props.every(hasInitial)) {
-    return false;
-  }
+  const uniqueProps = new Set(props.map((node) => node.value.toLowerCase()));
 
-  if (props.some(hasUnset) && !props.every(hasUnset)) {
-    return false;
+  if (uniqueProps.size > 1) {
+    for (const unmergeable of cssWideKeywords) {
+      if (uniqueProps.has(unmergeable)) {
+        return false;
+      }
+    }
   }
 
   if (