fix: triple __proto__ in object patterns should be allowed (#11009)

babel · Jan 16, 2020 · a1063d2 · a1063d2
1 parent 6363b59
commit a1063d2
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Showing 3 changed files with 267 additions and 3 deletions.
diff --git a/packages/babel-parser/src/parser/expression.js b/packages/babel-parser/src/parser/expression.js
@@ -88,10 +88,13 @@ export default class ExpressionParser extends LValParser {
     const name = key.type === "Identifier" ? key.name : String(key.value);
 
     if (name === "__proto__") {
-      // Store the first redefinition's position
       if (protoRef.used) {
-        if (refExpressionErrors && refExpressionErrors.doubleProto === -1) {
-          refExpressionErrors.doubleProto = key.start;
+        if (refExpressionErrors) {
+          // Store the first redefinition's position, otherwise ignore because
+          // we are parsing ambiguous pattern
+          if (refExpressionErrors.doubleProto === -1) {
+            refExpressionErrors.doubleProto = key.start;
+          }
         } else {
           this.raise(key.start, "Redefinition of __proto__ property");
         }

diff --git a/packages/babel-parser/test/fixtures/es2015/destructuring/duplicate-proto-4/input.js b/packages/babel-parser/test/fixtures/es2015/destructuring/duplicate-proto-4/input.js
@@ -0,0 +1 @@
+({ __proto__: x, __proto__: y, __proto__: z }) => {};
diff --git a/packages/babel-parser/test/fixtures/es2015/destructuring/duplicate-proto-4/output.json b/packages/babel-parser/test/fixtures/es2015/destructuring/duplicate-proto-4/output.json
@@ -0,0 +1,260 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 53,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 1,
+      "column": 53
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 53,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 1,
+        "column": 53
+      }
+    },
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 53,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 53
+          }
+        },
+        "expression": {
+          "type": "ArrowFunctionExpression",
+          "start": 0,
+          "end": 52,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 0
+            },
+            "end": {
+              "line": 1,
+              "column": 52
+            }
+          },
+          "id": null,
+          "generator": false,
+          "async": false,
+          "params": [
+            {
+              "type": "ObjectPattern",
+              "start": 1,
+              "end": 45,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 1
+                },
+                "end": {
+                  "line": 1,
+                  "column": 45
+                }
+              },
+              "properties": [
+                {
+                  "type": "ObjectProperty",
+                  "start": 3,
+                  "end": 15,
+                  "loc": {
+                    "start": {
+                      "line": 1,
+                      "column": 3
+                    },
+                    "end": {
+                      "line": 1,
+                      "column": 15
+                    }
+                  },
+                  "method": false,
+                  "key": {
+                    "type": "Identifier",
+                    "start": 3,
+                    "end": 12,
+                    "loc": {
+                      "start": {
+                        "line": 1,
+                        "column": 3
+                      },
+                      "end": {
+                        "line": 1,
+                        "column": 12
+                      },
+                      "identifierName": "__proto__"
+                    },
+                    "name": "__proto__"
+                  },
+                  "computed": false,
+                  "shorthand": false,
+                  "value": {
+                    "type": "Identifier",
+                    "start": 14,
+                    "end": 15,
+                    "loc": {
+                      "start": {
+                        "line": 1,
+                        "column": 14
+                      },
+                      "end": {
+                        "line": 1,
+                        "column": 15
+                      },
+                      "identifierName": "x"
+                    },
+                    "name": "x"
+                  }
+                },
+                {
+                  "type": "ObjectProperty",
+                  "start": 17,
+                  "end": 29,
+                  "loc": {
+                    "start": {
+                      "line": 1,
+                      "column": 17
+                    },
+                    "end": {
+                      "line": 1,
+                      "column": 29
+                    }
+                  },
+                  "method": false,
+                  "key": {
+                    "type": "Identifier",
+                    "start": 17,
+                    "end": 26,
+                    "loc": {
+                      "start": {
+                        "line": 1,
+                        "column": 17
+                      },
+                      "end": {
+                        "line": 1,
+                        "column": 26
+                      },
+                      "identifierName": "__proto__"
+                    },
+                    "name": "__proto__"
+                  },
+                  "computed": false,
+                  "shorthand": false,
+                  "value": {
+                    "type": "Identifier",
+                    "start": 28,
+                    "end": 29,
+                    "loc": {
+                      "start": {
+                        "line": 1,
+                        "column": 28
+                      },
+                      "end": {
+                        "line": 1,
+                        "column": 29
+                      },
+                      "identifierName": "y"
+                    },
+                    "name": "y"
+                  }
+                },
+                {
+                  "type": "ObjectProperty",
+                  "start": 31,
+                  "end": 43,
+                  "loc": {
+                    "start": {
+                      "line": 1,
+                      "column": 31
+                    },
+                    "end": {
+                      "line": 1,
+                      "column": 43
+                    }
+                  },
+                  "method": false,
+                  "key": {
+                    "type": "Identifier",
+                    "start": 31,
+                    "end": 40,
+                    "loc": {
+                      "start": {
+                        "line": 1,
+                        "column": 31
+                      },
+                      "end": {
+                        "line": 1,
+                        "column": 40
+                      },
+                      "identifierName": "__proto__"
+                    },
+                    "name": "__proto__"
+                  },
+                  "computed": false,
+                  "shorthand": false,
+                  "value": {
+                    "type": "Identifier",
+                    "start": 42,
+                    "end": 43,
+                    "loc": {
+                      "start": {
+                        "line": 1,
+                        "column": 42
+                      },
+                      "end": {
+                        "line": 1,
+                        "column": 43
+                      },
+                      "identifierName": "z"
+                    },
+                    "name": "z"
+                  }
+                }
+              ]
+            }
+          ],
+          "body": {
+            "type": "BlockStatement",
+            "start": 50,
+            "end": 52,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 50
+              },
+              "end": {
+                "line": 1,
+                "column": 52
+              }
+            },
+            "body": [],
+            "directives": []
+          }
+        }
+      }
+    ],
+    "directives": []
+  }
+}