fix(postcss-convert-values): preserve percent sign in percentage values in at-rules with double quotes (#1695)

Author: aramikuto

CONTRIBUTORS.md

@@ -72,3 +72,4 @@ Thanks goes to these wonderful people:
 - Xiaojun Zhou
 - Seth Falco
 - Seiya
+- Aleksandr Kondrashov

packages/postcss-convert-values/src/index.js

@@ -157,7 +157,7 @@ function shouldKeepZeroUnit(decl, browsers) {
         (node) =>
           node.type === 'decl' &&
           node.prop.toLowerCase() === 'syntax' &&
-          node.value === "'<percentage>'"
+          (node.value === "'<percentage>'" || node.value === '"<percentage>"')
       )) ||
     keepWhenZero.has(lowerCasedProp)
   );

packages/postcss-convert-values/test/index.js

@@ -504,6 +504,14 @@ test(
   )
 );
 
+test(
+  `should not strip the percentage from 0 in @property, for initial-value (syntax string in double quotes)`,
+  processCSS(
+    `@property --percent{syntax:"<percentage>";inherits:false;initial-value:0%;}`,
+    `@property --percent{syntax:"<percentage>";inherits:false;initial-value:0%;}`
+  )
+);
+
 test(
   'should not strip the percentage from background-color',
   passthroughCSS('background-color:color-mix(#000, #FFF 0%);')

packages/postcss-minify-selectors/test/index.js

@@ -109,7 +109,7 @@ test(
   processCSS(
     '.item1, .item2, .item10, .item11{color:blue}',
     '.item1,.item2,.item10,.item11{color:blue}',
-    { sort: false },
+    { sort: false }
   )
 );