Reinterpret << when parsing TS type arguments (#14145)

* refactor: split bitShift to bitShiftL and bitShiftR * fix: reinterpret bitShiftL to lt when parsing type arguments * test: update typescript allowlist * add Babel 8 test cases * test: simplify testcase * add more testcases
babel · Jan 24, 2022 · 5861002 · 5861002
1 parent 48cf642
commit 5861002
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Showing 44 changed files with 1,360 additions and 15 deletions.
diff --git a/packages/babel-parser/src/plugins/typescript/index.js b/packages/babel-parser/src/plugins/typescript/index.js
@@ -1974,6 +1974,15 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       );
     }
 
+    // Used when parsing type arguments from ES productions, where the first token
+    // has been created without state.inType. Thus we need to rescan the lt token.
+    tsParseTypeArgumentsInExpression(): N.TsTypeParameterInstantiation | void {
+      if (this.reScan_lt() !== tt.lt) {
+        return undefined;
+      }
+      return this.tsParseTypeArguments();
+    }
+
     tsParseTypeArguments(): N.TsTypeParameterInstantiation {
       const node = this.startNode();
       node.params = this.tsInType(() =>
@@ -2172,7 +2181,8 @@ export default (superClass: Class<Parser>): Class<Parser> =>
         this.next();
       }
 
-      if (this.match(tt.lt)) {
+      // handles 'f<<T>'
+      if (this.match(tt.lt) || this.match(tt.bitShiftL)) {
         let missingParenErrorLoc;
         // tsTryParseAndCatch is expensive, so avoid if not necessary.
         // There are number of things we are going to "maybe" parse, like type arguments on
@@ -2193,7 +2203,7 @@ export default (superClass: Class<Parser>): Class<Parser> =>
           const node: N.CallExpression = this.startNodeAt(startPos, startLoc);
           node.callee = base;
 
-          const typeArguments = this.tsParseTypeArguments();
+          const typeArguments = this.tsParseTypeArgumentsInExpression();
 
           if (typeArguments) {
             if (isOptionalCall && !this.match(tt.parenL)) {
@@ -2245,11 +2255,12 @@ export default (superClass: Class<Parser>): Class<Parser> =>
     }
 
     parseNewArguments(node: N.NewExpression): void {
-      if (this.match(tt.lt)) {
-        // tsTryParseAndCatch is expensive, so avoid if not necessary.
-        // 99% certain this is `new C<T>();`. But may be `new C < T;`, which is also legal.
+      // tsTryParseAndCatch is expensive, so avoid if not necessary.
+      // 99% certain this is `new C<T>();`. But may be `new C < T;`, which is also legal.
+      // Also handles `new C<<T>`
+      if (this.match(tt.lt) || this.match(tt.bitShiftL)) {
         const typeParameters = this.tsTryParseAndCatch(() => {
-          const args = this.tsParseTypeArguments();
+          const args = this.tsParseTypeArgumentsInExpression();
           if (!this.match(tt.parenL)) this.unexpected();
           return args;
         });
@@ -2832,8 +2843,9 @@ export default (superClass: Class<Parser>): Class<Parser> =>
 
     parseClassSuper(node: N.Class): void {
       super.parseClassSuper(node);
-      if (node.superClass && this.match(tt.lt)) {
-        node.superTypeParameters = this.tsParseTypeArguments();
+      // handle `extends f<<T>
+      if (node.superClass && (this.match(tt.lt) || this.match(tt.bitShiftL))) {
+        node.superTypeParameters = this.tsParseTypeArgumentsInExpression();
       }
       if (this.eatContextual(tt._implements)) {
         node.implements = this.tsParseHeritageClause("implements");
@@ -3146,8 +3158,9 @@ export default (superClass: Class<Parser>): Class<Parser> =>
     }
 
     parseMaybeDecoratorArguments(expr: N.Expression): N.Expression {
-      if (this.match(tt.lt)) {
-        const typeArguments = this.tsParseTypeArguments();
+      // handles `@f<<T>`
+      if (this.match(tt.lt) || this.match(tt.bitShiftL)) {
+        const typeArguments = this.tsParseTypeArgumentsInExpression();
 
         if (this.match(tt.parenL)) {
           const call = super.parseMaybeDecoratorArguments(expr);
@@ -3230,6 +3243,16 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       }
     }
 
+    reScan_lt() {
+      const { type } = this.state;
+      if (type === tt.bitShiftL) {
+        this.state.pos -= 2;
+        this.finishOp(tt.lt, 1);
+        return tt.lt;
+      }
+      return type;
+    }
+
     toAssignableList(exprList: N.Expression[]): $ReadOnlyArray<N.Pattern> {
       for (let i = 0; i < exprList.length; i++) {
         const expr = exprList[i];
@@ -3280,9 +3303,10 @@ export default (superClass: Class<Parser>): Class<Parser> =>
     jsxParseOpeningElementAfterName(
       node: N.JSXOpeningElement,
     ): N.JSXOpeningElement {
-      if (this.match(tt.lt)) {
+      // handles `<Component<<T>`
+      if (this.match(tt.lt) || this.match(tt.bitShiftL)) {
         const typeArguments = this.tsTryParseAndCatch(() =>
-          this.tsParseTypeArguments(),
+          this.tsParseTypeArgumentsInExpression(),
         );
         if (typeArguments) node.typeParameters = typeArguments;
       }

diff --git a/packages/babel-parser/src/tokenizer/index.js b/packages/babel-parser/src/tokenizer/index.js
@@ -755,7 +755,7 @@ export default class Tokenizer extends ParserErrors {
         this.finishOp(tt.assign, 3);
         return;
       }
-      this.finishOp(tt.bitShift, 2);
+      this.finishOp(tt.bitShiftL, 2);
       return;
     }
 
@@ -780,7 +780,7 @@ export default class Tokenizer extends ParserErrors {
         this.finishOp(tt.assign, size + 1);
         return;
       }
-      this.finishOp(tt.bitShift, size);
+      this.finishOp(tt.bitShiftR, size);
       return;
     }
 

diff --git a/packages/babel-parser/src/tokenizer/types.js b/packages/babel-parser/src/tokenizer/types.js
@@ -208,6 +208,8 @@ export const tt: { [name: string]: TokenType } = {
   gt: createBinop("</>/<=/>=", 7),
   relational: createBinop("</>/<=/>=", 7),
   bitShift: createBinop("<</>>/>>>", 8),
+  bitShiftL: createBinop("<</>>/>>>", 8),
+  bitShiftR: createBinop("<</>>/>>>", 8),
   plusMin: createToken("+/-", { beforeExpr, binop: 9, prefix, startsExpr }),
   // startsExpr: required by v8intrinsic plugin
   modulo: createToken("%", { binop: 10, startsExpr }),

diff --git a/...t/fixtures/typescript/type-arguments-bit-shift-left-like-babel-7/after-bit-shift/input.ts b/...t/fixtures/typescript/type-arguments-bit-shift-left-like-babel-7/after-bit-shift/input.ts
@@ -0,0 +1 @@
+f<<<T>(x)
diff --git a/...ixtures/typescript/type-arguments-bit-shift-left-like-babel-7/after-bit-shift/output.json b/...ixtures/typescript/type-arguments-bit-shift-left-like-babel-7/after-bit-shift/output.json
@@ -0,0 +1,49 @@
+{
+  "type": "File",
+  "start":0,"end":9,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":9}},
+  "program": {
+    "type": "Program",
+    "start":0,"end":9,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":9}},
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start":0,"end":9,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":9}},
+        "expression": {
+          "type": "BinaryExpression",
+          "start":0,"end":9,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":9}},
+          "left": {
+            "type": "Identifier",
+            "start":0,"end":1,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":1},"identifierName":"f"},
+            "name": "f"
+          },
+          "operator": "<<",
+          "right": {
+            "type": "TSTypeAssertion",
+            "start":3,"end":9,"loc":{"start":{"line":1,"column":3},"end":{"line":1,"column":9}},
+            "typeAnnotation": {
+              "type": "TSTypeReference",
+              "start":4,"end":5,"loc":{"start":{"line":1,"column":4},"end":{"line":1,"column":5}},
+              "typeName": {
+                "type": "Identifier",
+                "start":4,"end":5,"loc":{"start":{"line":1,"column":4},"end":{"line":1,"column":5},"identifierName":"T"},
+                "name": "T"
+              }
+            },
+            "expression": {
+              "type": "Identifier",
+              "start":7,"end":8,"loc":{"start":{"line":1,"column":7},"end":{"line":1,"column":8},"identifierName":"x"},
+              "name": "x",
+              "extra": {
+                "parenthesized": true,
+                "parenStart": 6
+              }
+            }
+          }
+        }
+      }
+    ],
+    "directives": []
+  }
+}
diff --git a/...t/fixtures/typescript/type-arguments-bit-shift-left-like-babel-7/call-expression/input.ts b/...t/fixtures/typescript/type-arguments-bit-shift-left-like-babel-7/call-expression/input.ts
@@ -0,0 +1 @@
+f<<T>(v: T) => void>();
diff --git a/...ixtures/typescript/type-arguments-bit-shift-left-like-babel-7/call-expression/output.json b/...ixtures/typescript/type-arguments-bit-shift-left-like-babel-7/call-expression/output.json
@@ -0,0 +1,76 @@
+{
+  "type": "File",
+  "start":0,"end":23,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":23}},
+  "program": {
+    "type": "Program",
+    "start":0,"end":23,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":23}},
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start":0,"end":23,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":23}},
+        "expression": {
+          "type": "CallExpression",
+          "start":0,"end":22,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":22}},
+          "callee": {
+            "type": "Identifier",
+            "start":0,"end":1,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":1},"identifierName":"f"},
+            "name": "f"
+          },
+          "arguments": [],
+          "typeParameters": {
+            "type": "TSTypeParameterInstantiation",
+            "start":1,"end":20,"loc":{"start":{"line":1,"column":1},"end":{"line":1,"column":20}},
+            "params": [
+              {
+                "type": "TSFunctionType",
+                "start":2,"end":19,"loc":{"start":{"line":1,"column":2},"end":{"line":1,"column":19}},
+                "typeParameters": {
+                  "type": "TSTypeParameterDeclaration",
+                  "start":2,"end":5,"loc":{"start":{"line":1,"column":2},"end":{"line":1,"column":5}},
+                  "params": [
+                    {
+                      "type": "TSTypeParameter",
+                      "start":3,"end":4,"loc":{"start":{"line":1,"column":3},"end":{"line":1,"column":4}},
+                      "name": "T"
+                    }
+                  ]
+                },
+                "parameters": [
+                  {
+                    "type": "Identifier",
+                    "start":6,"end":10,"loc":{"start":{"line":1,"column":6},"end":{"line":1,"column":10},"identifierName":"v"},
+                    "name": "v",
+                    "typeAnnotation": {
+                      "type": "TSTypeAnnotation",
+                      "start":7,"end":10,"loc":{"start":{"line":1,"column":7},"end":{"line":1,"column":10}},
+                      "typeAnnotation": {
+                        "type": "TSTypeReference",
+                        "start":9,"end":10,"loc":{"start":{"line":1,"column":9},"end":{"line":1,"column":10}},
+                        "typeName": {
+                          "type": "Identifier",
+                          "start":9,"end":10,"loc":{"start":{"line":1,"column":9},"end":{"line":1,"column":10},"identifierName":"T"},
+                          "name": "T"
+                        }
+                      }
+                    }
+                  }
+                ],
+                "typeAnnotation": {
+                  "type": "TSTypeAnnotation",
+                  "start":12,"end":19,"loc":{"start":{"line":1,"column":12},"end":{"line":1,"column":19}},
+                  "typeAnnotation": {
+                    "type": "TSVoidKeyword",
+                    "start":15,"end":19,"loc":{"start":{"line":1,"column":15},"end":{"line":1,"column":19}}
+                  }
+                }
+              }
+            ]
+          }
+        }
+      }
+    ],
+    "directives": []
+  }
+}
diff --git a/...st/fixtures/typescript/type-arguments-bit-shift-left-like-babel-7/class-heritage/input.ts b/...st/fixtures/typescript/type-arguments-bit-shift-left-like-babel-7/class-heritage/input.ts
@@ -0,0 +1 @@
+(class extends f<<T>(v: T) => void> {});
diff --git a/...fixtures/typescript/type-arguments-bit-shift-left-like-babel-7/class-heritage/output.json b/...fixtures/typescript/type-arguments-bit-shift-left-like-babel-7/class-heritage/output.json
@@ -0,0 +1,85 @@
+{
+  "type": "File",
+  "start":0,"end":40,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":40}},
+  "program": {
+    "type": "Program",
+    "start":0,"end":40,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":40}},
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ExpressionStatement",
+        "start":0,"end":40,"loc":{"start":{"line":1,"column":0},"end":{"line":1,"column":40}},
+        "expression": {
+          "type": "ClassExpression",
+          "start":1,"end":38,"loc":{"start":{"line":1,"column":1},"end":{"line":1,"column":38}},
+          "id": null,
+          "superClass": {
+            "type": "Identifier",
+            "start":15,"end":16,"loc":{"start":{"line":1,"column":15},"end":{"line":1,"column":16},"identifierName":"f"},
+            "name": "f"
+          },
+          "superTypeParameters": {
+            "type": "TSTypeParameterInstantiation",
+            "start":16,"end":35,"loc":{"start":{"line":1,"column":16},"end":{"line":1,"column":35}},
+            "params": [
+              {
+                "type": "TSFunctionType",
+                "start":17,"end":34,"loc":{"start":{"line":1,"column":17},"end":{"line":1,"column":34}},
+                "typeParameters": {
+                  "type": "TSTypeParameterDeclaration",
+                  "start":17,"end":20,"loc":{"start":{"line":1,"column":17},"end":{"line":1,"column":20}},
+                  "params": [
+                    {
+                      "type": "TSTypeParameter",
+                      "start":18,"end":19,"loc":{"start":{"line":1,"column":18},"end":{"line":1,"column":19}},
+                      "name": "T"
+                    }
+                  ]
+                },
+                "parameters": [
+                  {
+                    "type": "Identifier",
+                    "start":21,"end":25,"loc":{"start":{"line":1,"column":21},"end":{"line":1,"column":25},"identifierName":"v"},
+                    "name": "v",
+                    "typeAnnotation": {
+                      "type": "TSTypeAnnotation",
+                      "start":22,"end":25,"loc":{"start":{"line":1,"column":22},"end":{"line":1,"column":25}},
+                      "typeAnnotation": {
+                        "type": "TSTypeReference",
+                        "start":24,"end":25,"loc":{"start":{"line":1,"column":24},"end":{"line":1,"column":25}},
+                        "typeName": {
+                          "type": "Identifier",
+                          "start":24,"end":25,"loc":{"start":{"line":1,"column":24},"end":{"line":1,"column":25},"identifierName":"T"},
+                          "name": "T"
+                        }
+                      }
+                    }
+                  }
+                ],
+                "typeAnnotation": {
+                  "type": "TSTypeAnnotation",
+                  "start":27,"end":34,"loc":{"start":{"line":1,"column":27},"end":{"line":1,"column":34}},
+                  "typeAnnotation": {
+                    "type": "TSVoidKeyword",
+                    "start":30,"end":34,"loc":{"start":{"line":1,"column":30},"end":{"line":1,"column":34}}
+                  }
+                }
+              }
+            ]
+          },
+          "body": {
+            "type": "ClassBody",
+            "start":36,"end":38,"loc":{"start":{"line":1,"column":36},"end":{"line":1,"column":38}},
+            "body": []
+          },
+          "extra": {
+            "parenthesized": true,
+            "parenStart": 0
+          }
+        }
+      }
+    ],
+    "directives": []
+  }
+}
diff --git a/.../typescript/type-arguments-bit-shift-left-like-babel-7/decorator-call-expression/input.ts b/.../typescript/type-arguments-bit-shift-left-like-babel-7/decorator-call-expression/input.ts
@@ -0,0 +1 @@
+(@f<<T>(v: T) => void>() class {});
diff --git a/...escript/type-arguments-bit-shift-left-like-babel-7/decorator-call-expression/options.json b/...escript/type-arguments-bit-shift-left-like-babel-7/decorator-call-expression/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": [["decorators", { "decoratorsBeforeExport": true }], "typescript"]
+}