fix: handle escaping selectors (css-modules#10)

Author: evilebottnawi

src/index.js

@@ -51,6 +51,28 @@ function getSingleLocalNamesForComposes(root) {
   });
 }
 
+const whitespace = '[\\x20\\t\\r\\n\\f]';
+const unescapeRegExp = new RegExp(
+  '\\\\([\\da-f]{1,6}' + whitespace + '?|(' + whitespace + ')|.)',
+  'ig'
+);
+
+function unescape(str) {
+  return str.replace(unescapeRegExp, (_, escaped, escapedWhitespace) => {
+    const high = '0x' + escaped - 0x10000;
+
+    // NaN means non-codepoint
+    // Workaround erroneous numeric interpretation of +"0x"
+    return high !== high || escapedWhitespace
+      ? escaped
+      : high < 0
+        ? // BMP codepoint
+          String.fromCharCode(high + 0x10000)
+        : // Supplemental Plane codepoint (surrogate pair)
+          String.fromCharCode((high >> 10) | 0xd800, (high & 0x3ff) | 0xdc00);
+  });
+}
+
 const processor = postcss.plugin('postcss-modules-scope', function(options) {
   return css => {
     const generateScopedName =
@@ -64,10 +86,15 @@ const processor = postcss.plugin('postcss-modules-scope', function(options) {
         css.source.input.from,
         css.source.input.css
       );
+
       exports[name] = exports[name] || [];
-      if (exports[name].indexOf(scopedName) < 0) {
-        exports[name].push(scopedName);
+
+      const unescapedScopedName = unescape(scopedName);
+
+      if (exports[name].indexOf(unescapedScopedName) < 0) {
+        exports[name].push(unescapedScopedName);
       }
+
       return scopedName;
     }
 

test/test-cases/export-class/expected.css

@@ -10,6 +10,18 @@
   color: rebeccapurple;
 }
 
+._input__\31 a2b3c {
+  color: gainsboro;
+}
+
+._input__\32 {
+  color: aqua;
+}
+
+._input__𝌆 {
+  color: fuchsia;
+}
+
 @media (max-width: 520px) {
   /* selector doubled to increase specificity */
   ._input__exportName._input__exportName {
@@ -22,7 +34,10 @@
 }
 
 :export {
+  2: _input__2;
   exportName: _input__exportName;
-  ::::: _input__\:\:\:\:;
+  ::::: _input__::::;
+  1a2b3c: _input__1a2b3c;
+  𝌆: _input__𝌆;
   newExport: _input__newExport;
 }

test/test-cases/export-class/source.css

@@ -10,6 +10,18 @@
   color: rebeccapurple;
 }
 
+:local(.\31 a2b3c) {
+  color: gainsboro;
+}
+
+:local(.\32) {
+  color: aqua;
+}
+
+:local(.𝌆) {
+  color: fuchsia;
+}
+
 @media (max-width: 520px) {
   /* selector doubled to increase specificity */
   :local(.exportName):local(.exportName) {