fix: duplicate __proto__ keys should be allowed in patterns

babel · Jan 11, 2020 · 880891a · 880891a
1 parent 046c18c
commit 880891a
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Showing 9 changed files with 483 additions and 17 deletions.
diff --git a/packages/babel-parser/src/parser/expression.js b/packages/babel-parser/src/parser/expression.js
@@ -70,7 +70,8 @@ export default class ExpressionParser extends LValParser {
 
   checkDuplicatedProto(
     prop: N.ObjectMember | N.SpreadElement,
-    protoRef: { used: boolean, start?: number },
+    protoRef: { used: boolean },
+    refExpressionErrors: ?ExpressionErrors,
   ): void {
     if (
       prop.type === "SpreadElement" ||
@@ -88,8 +89,12 @@ export default class ExpressionParser extends LValParser {
 
     if (name === "__proto__") {
       // Store the first redefinition's position
-      if (protoRef.used && !protoRef.start) {
-        protoRef.start = key.start;
+      if (protoRef.used) {
+        if (refExpressionErrors && refExpressionErrors.doubleProto === -1) {
+          refExpressionErrors.doubleProto = key.start;
+        } else {
+          this.raise(key.start, "Redefinition of __proto__ property");
+        }
       }
 
       protoRef.used = true;
@@ -203,9 +208,12 @@ export default class ExpressionParser extends LValParser {
       if (operator === "||=" || operator === "&&=") {
         this.expectPlugin("logicalAssignment");
       }
-      node.left = this.match(tt.eq)
-        ? this.toAssignable(left, undefined, "assignment expression")
-        : left;
+      if (this.match(tt.eq)) {
+        node.left = this.toAssignable(left, undefined, "assignment expression");
+        refExpressionErrors.doubleProto = -1; // reset because double __proto__ is valid in assignment expression
+      } else {
+        node.left = left;
+      }
 
       if (refExpressionErrors.shorthandAssign >= node.left.start) {
         refExpressionErrors.shorthandAssign = -1; // reset because shorthand default was used correctly
@@ -1513,8 +1521,10 @@ export default class ExpressionParser extends LValParser {
       }
 
       const prop = this.parseObjectMember(isPattern, refExpressionErrors);
-      // $FlowIgnore RestElement will never be returned if !isPattern
-      if (!isPattern) this.checkDuplicatedProto(prop, propHash);
+      if (!isPattern) {
+        // $FlowIgnore RestElement will never be returned if !isPattern
+        this.checkDuplicatedProto(prop, propHash, refExpressionErrors);
+      }
 
       // $FlowIgnore
       if (prop.shorthand) {
@@ -1524,10 +1534,6 @@ export default class ExpressionParser extends LValParser {
       node.properties.push(prop);
     }
 
-    if (!this.match(tt.eq) && propHash.start !== undefined) {
-      this.raise(propHash.start, "Redefinition of __proto__ property");
-    }
-
     return this.finishNode(
       node,
       isPattern ? "ObjectPattern" : "ObjectExpression",

diff --git a/packages/babel-parser/src/parser/util.js b/packages/babel-parser/src/parser/util.js
@@ -274,11 +274,14 @@ export default class UtilParser extends Tokenizer {
     andThrow: boolean,
   ) {
     if (!refExpressionErrors) return false;
-    const { shorthandAssign } = refExpressionErrors;
-    if (!andThrow) return shorthandAssign >= 0;
+    const { shorthandAssign, doubleProto } = refExpressionErrors;
+    if (!andThrow) return shorthandAssign >= 0 || doubleProto >= 0;
     if (shorthandAssign >= 0) {
       this.unexpected(shorthandAssign);
     }
+    if (doubleProto >= 0) {
+      this.raise(doubleProto, "Redefinition of __proto__ property");
+    }
   }
 }
 
@@ -290,4 +293,5 @@ export default class UtilParser extends Tokenizer {
  */
 export class ExpressionErrors {
   shorthandAssign = -1;
+  doubleProto = -1;
 }
diff --git a/packages/babel-parser/src/plugins/estree.js b/packages/babel-parser/src/plugins/estree.js
@@ -149,7 +149,8 @@ export default (superClass: Class<Parser>): Class<Parser> =>
 
     checkDuplicatedProto(
       prop: N.ObjectMember | N.SpreadElement,
-      protoRef: { used: boolean, start?: number },
+      protoRef: { used: boolean },
+      refExpressionErrors: ?ExpressionErrors,
     ): void {
       if (
         prop.type === "SpreadElement" ||
@@ -167,8 +168,12 @@ export default (superClass: Class<Parser>): Class<Parser> =>
 
       if (name === "__proto__" && prop.kind === "init") {
         // Store the first redefinition's position
-        if (protoRef.used && !protoRef.start) {
-          protoRef.start = key.start;
+        if (protoRef.used) {
+          if (refExpressionErrors && refExpressionErrors.doubleProto === -1) {
+            refExpressionErrors.doubleProto = key.start;
+          } else {
+            this.raise(key.start, "Redefinition of __proto__ property");
+          }
         }
 
         protoRef.used = true;

diff --git a/...15/destructuring/duplicate-proto/input.js → .../destructuring/duplicate-proto-1/input.js b/...15/destructuring/duplicate-proto/input.js → .../destructuring/duplicate-proto-1/input.js
diff --git a/...destructuring/duplicate-proto/output.json → ...structuring/duplicate-proto-1/output.json b/...destructuring/duplicate-proto/output.json → ...structuring/duplicate-proto-1/output.json
diff --git a/packages/babel-parser/test/fixtures/es2015/destructuring/duplicate-proto-2/input.js b/packages/babel-parser/test/fixtures/es2015/destructuring/duplicate-proto-2/input.js
@@ -0,0 +1 @@
+([{ __proto__: x, __proto__: y }] = [{}]);
diff --git a/packages/babel-parser/test/fixtures/es2015/destructuring/duplicate-proto-2/output.json b/packages/babel-parser/test/fixtures/es2015/destructuring/duplicate-proto-2/output.json
@@ -0,0 +1,241 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 42,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 1,
+      "column": 42
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 42,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 1,
+        "column": 42
+      }
+    },
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start": 0,
+        "end": 42,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 42
+          }
+        },
+        "expression": {
+          "type": "AssignmentExpression",
+          "start": 1,
+          "end": 40,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 1
+            },
+            "end": {
+              "line": 1,
+              "column": 40
+            }
+          },
+          "operator": "=",
+          "left": {
+            "type": "ArrayPattern",
+            "start": 1,
+            "end": 33,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 1
+              },
+              "end": {
+                "line": 1,
+                "column": 33
+              }
+            },
+            "elements": [
+              {
+                "type": "ObjectPattern",
+                "start": 2,
+                "end": 32,
+                "loc": {
+                  "start": {
+                    "line": 1,
+                    "column": 2
+                  },
+                  "end": {
+                    "line": 1,
+                    "column": 32
+                  }
+                },
+                "properties": [
+                  {
+                    "type": "ObjectProperty",
+                    "start": 4,
+                    "end": 16,
+                    "loc": {
+                      "start": {
+                        "line": 1,
+                        "column": 4
+                      },
+                      "end": {
+                        "line": 1,
+                        "column": 16
+                      }
+                    },
+                    "method": false,
+                    "key": {
+                      "type": "Identifier",
+                      "start": 4,
+                      "end": 13,
+                      "loc": {
+                        "start": {
+                          "line": 1,
+                          "column": 4
+                        },
+                        "end": {
+                          "line": 1,
+                          "column": 13
+                        },
+                        "identifierName": "__proto__"
+                      },
+                      "name": "__proto__"
+                    },
+                    "computed": false,
+                    "shorthand": false,
+                    "value": {
+                      "type": "Identifier",
+                      "start": 15,
+                      "end": 16,
+                      "loc": {
+                        "start": {
+                          "line": 1,
+                          "column": 15
+                        },
+                        "end": {
+                          "line": 1,
+                          "column": 16
+                        },
+                        "identifierName": "x"
+                      },
+                      "name": "x"
+                    }
+                  },
+                  {
+                    "type": "ObjectProperty",
+                    "start": 18,
+                    "end": 30,
+                    "loc": {
+                      "start": {
+                        "line": 1,
+                        "column": 18
+                      },
+                      "end": {
+                        "line": 1,
+                        "column": 30
+                      }
+                    },
+                    "method": false,
+                    "key": {
+                      "type": "Identifier",
+                      "start": 18,
+                      "end": 27,
+                      "loc": {
+                        "start": {
+                          "line": 1,
+                          "column": 18
+                        },
+                        "end": {
+                          "line": 1,
+                          "column": 27
+                        },
+                        "identifierName": "__proto__"
+                      },
+                      "name": "__proto__"
+                    },
+                    "computed": false,
+                    "shorthand": false,
+                    "value": {
+                      "type": "Identifier",
+                      "start": 29,
+                      "end": 30,
+                      "loc": {
+                        "start": {
+                          "line": 1,
+                          "column": 29
+                        },
+                        "end": {
+                          "line": 1,
+                          "column": 30
+                        },
+                        "identifierName": "y"
+                      },
+                      "name": "y"
+                    }
+                  }
+                ]
+              }
+            ]
+          },
+          "right": {
+            "type": "ArrayExpression",
+            "start": 36,
+            "end": 40,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 36
+              },
+              "end": {
+                "line": 1,
+                "column": 40
+              }
+            },
+            "elements": [
+              {
+                "type": "ObjectExpression",
+                "start": 37,
+                "end": 39,
+                "loc": {
+                  "start": {
+                    "line": 1,
+                    "column": 37
+                  },
+                  "end": {
+                    "line": 1,
+                    "column": 39
+                  }
+                },
+                "properties": []
+              }
+            ]
+          },
+          "extra": {
+            "parenthesized": true,
+            "parenStart": 0
+          }
+        }
+      }
+    ],
+    "directives": []
+  }
+}
diff --git a/packages/babel-parser/test/fixtures/es2015/destructuring/duplicate-proto-3/input.js b/packages/babel-parser/test/fixtures/es2015/destructuring/duplicate-proto-3/input.js
@@ -0,0 +1 @@
+({ __proto__: x, __proto__: y }) => {};