Merge pull request #151 from babel/fix-annex-b-reverse-solidus-c

annex-b: \ can be ClassAtomNoDash if followed by c
jviereck · Oct 25, 2024 · fd2bc4d · fd2bc4d
2 parents f2b6095 + 0868c5d
commit fd2bc4d
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diff --git a/parser.js b/parser.js
@@ -1386,13 +1386,19 @@
       // ClassAtomNoDash ::
       //      SourceCharacter but not one of \ or ] or -
       //      \ ClassEscape
+      //
+      // ClassAtomNoDash (Annex B)::
+      //      \ [lookahead = c] 
 
       var res;
       if (res = matchReg(/^[^\\\]-]/)) {
         return createCharacter(res[0]);
       } else if (match('\\')) {
         res = parseClassEscape();
         if (!res) {
+          if (!isUnicodeMode && lookahead() == 'c') {
+            return createCharacter('\\');
+          }
           bail('classEscape');
         }
 

diff --git a/test/test-data-unicode.json b/test/test-data-unicode.json
@@ -1872,5 +1872,11 @@
     "name": "SyntaxError",
     "message": "Expected atom at position 2\n    \\B{1}\n      ^",
     "input": "\\B{1}"
+  },
+  "[\\c]": {
+    "type": "error",
+    "name": "SyntaxError",
+    "message": "classEscape at position 2\n    [\\c]\n      ^",
+    "input": "[\\c]"
   }
 }
diff --git a/test/test-data.json b/test/test-data.json
@@ -38627,6 +38627,38 @@
     ],
     "raw": ".(?!.){2,3}"
   },
+  "[\\c]": {
+    "type": "characterClass",
+    "kind": "union",
+    "body": [
+      {
+        "type": "value",
+        "kind": "symbol",
+        "codePoint": 92,
+        "range": [
+          1,
+          2
+        ],
+        "raw": "\\"
+      },
+      {
+        "type": "value",
+        "kind": "symbol",
+        "codePoint": 99,
+        "range": [
+          2,
+          3
+        ],
+        "raw": "c"
+      }
+    ],
+    "negative": false,
+    "range": [
+      0,
+      4
+    ],
+    "raw": "[\\c]"
+  },
   "^*": {
     "type": "error",
     "name": "SyntaxError",