[ts 4.7] Support extends constraints for infer (#14476)

babel · May 17, 2022 · 59d24a4 · 59d24a4
1 parent d6ff919
commit 59d24a4
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Showing 17 changed files with 1,637 additions and 6 deletions.
diff --git a/packages/babel-generator/test/fixtures/typescript/infer-with-constraints/input.ts b/packages/babel-generator/test/fixtures/typescript/infer-with-constraints/input.ts
@@ -0,0 +1,5 @@
+type X3<T> = T extends [infer U extends number] ? MustBeNumber<U> : never;
+type X4<T> = T extends [infer U extends number, infer U extends number] ? MustBeNumber<U> : never;
+type X5<T> = T extends [infer U extends number, infer U] ? MustBeNumber<U> : never;
+type X6<T> = T extends [infer U, infer U extends number] ? MustBeNumber<U> : never;
+type X7<T> = T extends [infer U extends string, infer U extends number] ? U : never;
diff --git a/packages/babel-generator/test/fixtures/typescript/infer-with-constraints/output.js b/packages/babel-generator/test/fixtures/typescript/infer-with-constraints/output.js
@@ -0,0 +1,5 @@
+type X3<T> = T extends [infer U extends number] ? MustBeNumber<U> : never;
+type X4<T> = T extends [infer U extends number, infer U extends number] ? MustBeNumber<U> : never;
+type X5<T> = T extends [infer U extends number, infer U] ? MustBeNumber<U> : never;
+type X6<T> = T extends [infer U, infer U extends number] ? MustBeNumber<U> : never;
+type X7<T> = T extends [infer U extends string, infer U extends number] ? U : never;
diff --git a/packages/babel-parser/src/plugins/typescript/index.js b/packages/babel-parser/src/plugins/typescript/index.js
@@ -1271,18 +1271,37 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       this.expectContextual(tt._infer);
       const typeParameter = this.startNode();
       typeParameter.name = this.tsParseTypeParameterName();
+      typeParameter.constraint = this.tsTryParse(() =>
+        this.tsParseConstraintForInferType(),
+      );
       node.typeParameter = this.finishNode(typeParameter, "TSTypeParameter");
       return this.finishNode(node, "TSInferType");
     }
 
+    tsParseConstraintForInferType() {
+      if (this.eat(tt._extends)) {
+        const constraint = this.tsInDisallowConditionalTypesContext(() =>
+          this.tsParseType(),
+        );
+        if (
+          this.state.inDisallowConditionalTypesContext ||
+          !this.match(tt.question)
+        ) {
+          return constraint;
+        }
+      }
+    }
+
     tsParseTypeOperatorOrHigher(): N.TsType {
       const isTypeOperator =
         tokenIsTSTypeOperator(this.state.type) && !this.state.containsEsc;
       return isTypeOperator
         ? this.tsParseTypeOperator()
         : this.isContextual(tt._infer)
         ? this.tsParseInferType()
-        : this.tsParseArrayTypeOrHigher();
+        : this.tsInAllowConditionalTypesContext(() =>
+            this.tsParseArrayTypeOrHigher(),
+          );
     }
 
     tsParseUnionOrIntersectionType(
@@ -1516,16 +1535,31 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       // Need to set `state.inType` so that we don't parse JSX in a type context.
       assert(this.state.inType);
       const type = this.tsParseNonConditionalType();
-      if (this.hasPrecedingLineBreak() || !this.eat(tt._extends)) {
+
+      if (
+        this.state.inDisallowConditionalTypesContext ||
+        this.hasPrecedingLineBreak() ||
+        !this.eat(tt._extends)
+      ) {
         return type;
       }
       const node: N.TsConditionalType = this.startNodeAtNode(type);
       node.checkType = type;
-      node.extendsType = this.tsParseNonConditionalType();
+
+      node.extendsType = this.tsInDisallowConditionalTypesContext(() =>
+        this.tsParseNonConditionalType(),
+      );
+
       this.expect(tt.question);
-      node.trueType = this.tsParseType();
+      node.trueType = this.tsInAllowConditionalTypesContext(() =>
+        this.tsParseType(),
+      );
+
       this.expect(tt.colon);
-      node.falseType = this.tsParseType();
+      node.falseType = this.tsInAllowConditionalTypesContext(() =>
+        this.tsParseType(),
+      );
+
       return this.finishNode(node, "TSConditionalType");
     }
 
@@ -1668,6 +1702,30 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       }
     }
 
+    tsInDisallowConditionalTypesContext<T>(cb: () => T): T {
+      const oldInDisallowConditionalTypesContext =
+        this.state.inDisallowConditionalTypesContext;
+      this.state.inDisallowConditionalTypesContext = true;
+      try {
+        return cb();
+      } finally {
+        this.state.inDisallowConditionalTypesContext =
+          oldInDisallowConditionalTypesContext;
+      }
+    }
+
+    tsInAllowConditionalTypesContext<T>(cb: () => T): T {
+      const oldInDisallowConditionalTypesContext =
+        this.state.inDisallowConditionalTypesContext;
+      this.state.inDisallowConditionalTypesContext = false;
+      try {
+        return cb();
+      } finally {
+        this.state.inDisallowConditionalTypesContext =
+          oldInDisallowConditionalTypesContext;
+      }
+    }
+
     tsEatThenParseType(token: TokenType): N.TsType | typeof undefined {
       return !this.match(token) ? undefined : this.tsNextThenParseType();
     }

diff --git a/packages/babel-parser/src/tokenizer/state.js b/packages/babel-parser/src/tokenizer/state.js
@@ -75,6 +75,7 @@ export default class State {
   hasFlowComment: boolean = false;
   isAmbientContext: boolean = false;
   inAbstractClass: boolean = false;
+  inDisallowConditionalTypesContext: boolean = false;
 
   // For the Hack-style pipelines plugin
   topicContext: TopicContextState = {

diff --git a/packages/babel-parser/src/types.js b/packages/babel-parser/src/types.js
@@ -1476,7 +1476,7 @@ export type TsConditionalType = TsTypeBase & {
 
 export type TsInferType = TsTypeBase & {
   type: "TSInferType",
-  typeParameter: TypeParameter,
+  typeParameter: TsTypeParameter,
 };
 
 export type TsParenthesizedType = TsTypeBase & {

diff --git a/...t/fixtures/typescript/types/infer-with-constraints-and-conditional-types-babel-7/input.ts b/...t/fixtures/typescript/types/infer-with-constraints-and-conditional-types-babel-7/input.ts
@@ -0,0 +1 @@
+type X<U, T> = T extends [infer U extends T ? U : T] ? U : T;
diff --git a/...xtures/typescript/types/infer-with-constraints-and-conditional-types-babel-7/options.json b/...xtures/typescript/types/infer-with-constraints-and-conditional-types-babel-7/options.json
@@ -0,0 +1,3 @@
+{
+  "BABEL_8_BREAKING": false
+}
diff --git a/...ixtures/typescript/types/infer-with-constraints-and-conditional-types-babel-7/output.json b/...ixtures/typescript/types/infer-with-constraints-and-conditional-types-babel-7/output.json
@@ -0,0 +1,115 @@
+{
+  "type": "File",
+  "start":0,"end":61,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":61,"index":61}},
+  "program": {
+    "type": "Program",
+    "start":0,"end":61,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":61,"index":61}},
+    "sourceType": "module",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "TSTypeAliasDeclaration",
+        "start":0,"end":61,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":61,"index":61}},
+        "id": {
+          "type": "Identifier",
+          "start":5,"end":6,"loc":{"start":{"line":1,"column":5,"index":5},"end":{"line":1,"column":6,"index":6},"identifierName":"X"},
+          "name": "X"
+        },
+        "typeParameters": {
+          "type": "TSTypeParameterDeclaration",
+          "start":6,"end":12,"loc":{"start":{"line":1,"column":6,"index":6},"end":{"line":1,"column":12,"index":12}},
+          "params": [
+            {
+              "type": "TSTypeParameter",
+              "start":7,"end":8,"loc":{"start":{"line":1,"column":7,"index":7},"end":{"line":1,"column":8,"index":8}},
+              "name": "U"
+            },
+            {
+              "type": "TSTypeParameter",
+              "start":10,"end":11,"loc":{"start":{"line":1,"column":10,"index":10},"end":{"line":1,"column":11,"index":11}},
+              "name": "T"
+            }
+          ]
+        },
+        "typeAnnotation": {
+          "type": "TSConditionalType",
+          "start":15,"end":60,"loc":{"start":{"line":1,"column":15,"index":15},"end":{"line":1,"column":60,"index":60}},
+          "checkType": {
+            "type": "TSTypeReference",
+            "start":15,"end":16,"loc":{"start":{"line":1,"column":15,"index":15},"end":{"line":1,"column":16,"index":16}},
+            "typeName": {
+              "type": "Identifier",
+              "start":15,"end":16,"loc":{"start":{"line":1,"column":15,"index":15},"end":{"line":1,"column":16,"index":16},"identifierName":"T"},
+              "name": "T"
+            }
+          },
+          "extendsType": {
+            "type": "TSTupleType",
+            "start":25,"end":52,"loc":{"start":{"line":1,"column":25,"index":25},"end":{"line":1,"column":52,"index":52}},
+            "elementTypes": [
+              {
+                "type": "TSConditionalType",
+                "start":26,"end":51,"loc":{"start":{"line":1,"column":26,"index":26},"end":{"line":1,"column":51,"index":51}},
+                "checkType": {
+                  "type": "TSInferType",
+                  "start":26,"end":33,"loc":{"start":{"line":1,"column":26,"index":26},"end":{"line":1,"column":33,"index":33}},
+                  "typeParameter": {
+                    "type": "TSTypeParameter",
+                    "start":32,"end":33,"loc":{"start":{"line":1,"column":32,"index":32},"end":{"line":1,"column":33,"index":33}},
+                    "name": "U"
+                  }
+                },
+                "extendsType": {
+                  "type": "TSTypeReference",
+                  "start":42,"end":43,"loc":{"start":{"line":1,"column":42,"index":42},"end":{"line":1,"column":43,"index":43}},
+                  "typeName": {
+                    "type": "Identifier",
+                    "start":42,"end":43,"loc":{"start":{"line":1,"column":42,"index":42},"end":{"line":1,"column":43,"index":43},"identifierName":"T"},
+                    "name": "T"
+                  }
+                },
+                "trueType": {
+                  "type": "TSTypeReference",
+                  "start":46,"end":47,"loc":{"start":{"line":1,"column":46,"index":46},"end":{"line":1,"column":47,"index":47}},
+                  "typeName": {
+                    "type": "Identifier",
+                    "start":46,"end":47,"loc":{"start":{"line":1,"column":46,"index":46},"end":{"line":1,"column":47,"index":47},"identifierName":"U"},
+                    "name": "U"
+                  }
+                },
+                "falseType": {
+                  "type": "TSTypeReference",
+                  "start":50,"end":51,"loc":{"start":{"line":1,"column":50,"index":50},"end":{"line":1,"column":51,"index":51}},
+                  "typeName": {
+                    "type": "Identifier",
+                    "start":50,"end":51,"loc":{"start":{"line":1,"column":50,"index":50},"end":{"line":1,"column":51,"index":51},"identifierName":"T"},
+                    "name": "T"
+                  }
+                }
+              }
+            ]
+          },
+          "trueType": {
+            "type": "TSTypeReference",
+            "start":55,"end":56,"loc":{"start":{"line":1,"column":55,"index":55},"end":{"line":1,"column":56,"index":56}},
+            "typeName": {
+              "type": "Identifier",
+              "start":55,"end":56,"loc":{"start":{"line":1,"column":55,"index":55},"end":{"line":1,"column":56,"index":56},"identifierName":"U"},
+              "name": "U"
+            }
+          },
+          "falseType": {
+            "type": "TSTypeReference",
+            "start":59,"end":60,"loc":{"start":{"line":1,"column":59,"index":59},"end":{"line":1,"column":60,"index":60}},
+            "typeName": {
+              "type": "Identifier",
+              "start":59,"end":60,"loc":{"start":{"line":1,"column":59,"index":59},"end":{"line":1,"column":60,"index":60},"identifierName":"T"},
+              "name": "T"
+            }
+          }
+        }
+      }
+    ],
+    "directives": []
+  }
+}
diff --git a/...rser/test/fixtures/typescript/types/infer-with-constraints-and-conditional-types/input.ts b/...rser/test/fixtures/typescript/types/infer-with-constraints-and-conditional-types/input.ts
@@ -0,0 +1 @@
+type X<U, T> = T extends [infer U extends T ? U : T] ? U : T;
diff --git a/.../test/fixtures/typescript/types/infer-with-constraints-and-conditional-types/options.json b/.../test/fixtures/typescript/types/infer-with-constraints-and-conditional-types/options.json
@@ -0,0 +1,3 @@
+{
+  "BABEL_8_BREAKING": true
+}
diff --git a/...r/test/fixtures/typescript/types/infer-with-constraints-and-conditional-types/output.json b/...r/test/fixtures/typescript/types/infer-with-constraints-and-conditional-types/output.json
@@ -0,0 +1,127 @@
+{
+  "type": "File",
+  "start":0,"end":61,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":61,"index":61}},
+  "program": {
+    "type": "Program",
+    "start":0,"end":61,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":61,"index":61}},
+    "sourceType": "module",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "TSTypeAliasDeclaration",
+        "start":0,"end":61,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":61,"index":61}},
+        "id": {
+          "type": "Identifier",
+          "start":5,"end":6,"loc":{"start":{"line":1,"column":5,"index":5},"end":{"line":1,"column":6,"index":6},"identifierName":"X"},
+          "name": "X"
+        },
+        "typeParameters": {
+          "type": "TSTypeParameterDeclaration",
+          "start":6,"end":12,"loc":{"start":{"line":1,"column":6,"index":6},"end":{"line":1,"column":12,"index":12}},
+          "params": [
+            {
+              "type": "TSTypeParameter",
+              "start":7,"end":8,"loc":{"start":{"line":1,"column":7,"index":7},"end":{"line":1,"column":8,"index":8}},
+              "name": {
+                "type": "Identifier",
+                "start":7,"end":8,"loc":{"start":{"line":1,"column":7,"index":7},"end":{"line":1,"column":8,"index":8},"identifierName":"U"},
+                "name": "U"
+              }
+            },
+            {
+              "type": "TSTypeParameter",
+              "start":10,"end":11,"loc":{"start":{"line":1,"column":10,"index":10},"end":{"line":1,"column":11,"index":11}},
+              "name": {
+                "type": "Identifier",
+                "start":10,"end":11,"loc":{"start":{"line":1,"column":10,"index":10},"end":{"line":1,"column":11,"index":11},"identifierName":"T"},
+                "name": "T"
+              }
+            }
+          ]
+        },
+        "typeAnnotation": {
+          "type": "TSConditionalType",
+          "start":15,"end":60,"loc":{"start":{"line":1,"column":15,"index":15},"end":{"line":1,"column":60,"index":60}},
+          "checkType": {
+            "type": "TSTypeReference",
+            "start":15,"end":16,"loc":{"start":{"line":1,"column":15,"index":15},"end":{"line":1,"column":16,"index":16}},
+            "typeName": {
+              "type": "Identifier",
+              "start":15,"end":16,"loc":{"start":{"line":1,"column":15,"index":15},"end":{"line":1,"column":16,"index":16},"identifierName":"T"},
+              "name": "T"
+            }
+          },
+          "extendsType": {
+            "type": "TSTupleType",
+            "start":25,"end":52,"loc":{"start":{"line":1,"column":25,"index":25},"end":{"line":1,"column":52,"index":52}},
+            "elementTypes": [
+              {
+                "type": "TSConditionalType",
+                "start":26,"end":51,"loc":{"start":{"line":1,"column":26,"index":26},"end":{"line":1,"column":51,"index":51}},
+                "checkType": {
+                  "type": "TSInferType",
+                  "start":26,"end":33,"loc":{"start":{"line":1,"column":26,"index":26},"end":{"line":1,"column":33,"index":33}},
+                  "typeParameter": {
+                    "type": "TSTypeParameter",
+                    "start":32,"end":33,"loc":{"start":{"line":1,"column":32,"index":32},"end":{"line":1,"column":33,"index":33}},
+                    "name": {
+                      "type": "Identifier",
+                      "start":32,"end":33,"loc":{"start":{"line":1,"column":32,"index":32},"end":{"line":1,"column":33,"index":33},"identifierName":"U"},
+                      "name": "U"
+                    }
+                  }
+                },
+                "extendsType": {
+                  "type": "TSTypeReference",
+                  "start":42,"end":43,"loc":{"start":{"line":1,"column":42,"index":42},"end":{"line":1,"column":43,"index":43}},
+                  "typeName": {
+                    "type": "Identifier",
+                    "start":42,"end":43,"loc":{"start":{"line":1,"column":42,"index":42},"end":{"line":1,"column":43,"index":43},"identifierName":"T"},
+                    "name": "T"
+                  }
+                },
+                "trueType": {
+                  "type": "TSTypeReference",
+                  "start":46,"end":47,"loc":{"start":{"line":1,"column":46,"index":46},"end":{"line":1,"column":47,"index":47}},
+                  "typeName": {
+                    "type": "Identifier",
+                    "start":46,"end":47,"loc":{"start":{"line":1,"column":46,"index":46},"end":{"line":1,"column":47,"index":47},"identifierName":"U"},
+                    "name": "U"
+                  }
+                },
+                "falseType": {
+                  "type": "TSTypeReference",
+                  "start":50,"end":51,"loc":{"start":{"line":1,"column":50,"index":50},"end":{"line":1,"column":51,"index":51}},
+                  "typeName": {
+                    "type": "Identifier",
+                    "start":50,"end":51,"loc":{"start":{"line":1,"column":50,"index":50},"end":{"line":1,"column":51,"index":51},"identifierName":"T"},
+                    "name": "T"
+                  }
+                }
+              }
+            ]
+          },
+          "trueType": {
+            "type": "TSTypeReference",
+            "start":55,"end":56,"loc":{"start":{"line":1,"column":55,"index":55},"end":{"line":1,"column":56,"index":56}},
+            "typeName": {
+              "type": "Identifier",
+              "start":55,"end":56,"loc":{"start":{"line":1,"column":55,"index":55},"end":{"line":1,"column":56,"index":56},"identifierName":"U"},
+              "name": "U"
+            }
+          },
+          "falseType": {
+            "type": "TSTypeReference",
+            "start":59,"end":60,"loc":{"start":{"line":1,"column":59,"index":59},"end":{"line":1,"column":60,"index":60}},
+            "typeName": {
+              "type": "Identifier",
+              "start":59,"end":60,"loc":{"start":{"line":1,"column":59,"index":59},"end":{"line":1,"column":60,"index":60},"identifierName":"T"},
+              "name": "T"
+            }
+          }
+        }
+      }
+    ],
+    "directives": []
+  }
+}
diff --git a/packages/babel-parser/test/fixtures/typescript/types/infer-with-constraints-babel-7/input.ts b/packages/babel-parser/test/fixtures/typescript/types/infer-with-constraints-babel-7/input.ts
@@ -0,0 +1,7 @@
+type X3<T> = T extends [infer U extends number] ? MustBeNumber<U> : never;
+type X4<T> = T extends [infer U extends number, infer U extends number] ? MustBeNumber<U> : never;
+type X5<T> = T extends [infer U extends number, infer U] ? MustBeNumber<U> : never;
+type X6<T> = T extends [infer U, infer U extends number] ? MustBeNumber<U> : never;
+type X7<T> = T extends [infer U extends string, infer U extends number] ? U : never;
+type X8<U, T> = T extends infer U extends number ? U : T;
+type X9<U, T> = T extends (infer U extends number ? U : T) ? U : T;