Support TypeScript 4.3 get/set type members

packages/babel-generator/src/generators/typescript.ts

@@ -127,6 +127,11 @@ export function tsPrintPropertyOrMethodName(this: Printer, node) {
 }
 
 export function TSMethodSignature(this: Printer, node: t.TSMethodSignature) {
+  const { kind } = node;
+  if (kind === "set" || kind === "get") {
+    this.word(kind);
+    this.space();
+  }
   this.tsPrintPropertyOrMethodName(node);
   this.tsPrintSignatureDeclarationBase(node);
   this.token(";");

packages/babel-generator/test/fixtures/typescript/interface-method-kind/input.js

@@ -0,0 +1,4 @@
+interface Foo {
+  get foo();
+  set bar(v);
+}

packages/babel-generator/test/fixtures/typescript/interface-method-kind/output.js

@@ -0,0 +1,4 @@
+interface Foo {
+  get foo();
+  set bar(v);
+}

packages/babel-parser/src/parser/statement.js

@@ -2384,4 +2384,12 @@ export default class StatementParser extends ExpressionParser {
     this.checkLVal(specifier.local, "import specifier", BIND_LEXICAL);
     node.specifiers.push(this.finishNode(specifier, "ImportSpecifier"));
   }
+
+  // This is used in flow and typescript plugin
+  // Determine whether a parameter is a this param
+  isThisParam(
+    param: N.Pattern | N.Identifier | N.TSParameterProperty,
+  ): boolean {
+    return param.type === "Identifier" && param.name === "this";
+  }
 }

packages/babel-parser/src/plugins/flow/index.js

@@ -2392,11 +2392,6 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       return !this.match(tt.colon) && super.isNonstaticConstructor(method);
     }
 
-    // determine whether a parameter is a this param
-    isThisParam(param) {
-      return param.type === "Identifier" && param.name === "this";
-    }
-
     // parse type parameters for class methods
     pushClassMethod(
       classBody: N.ClassBody,

packages/babel-parser/src/plugins/typescript/index.js

@@ -70,6 +70,9 @@ const TSErrors = makeErrorTemplates(
   {
     AbstractMethodHasImplementation:
       "Method '%0' cannot have an implementation because it is marked abstract.",
+    AccesorCannotDeclareThisParameter:
+      "'get' and 'set' accessors cannot declare 'this' parameters.",
+    AccesorCannotHaveTypeParameters: "An accessor cannot have type parameters.",
     ClassMethodHasDeclare: "Class methods cannot have the 'declare' modifier.",
     ClassMethodHasReadonly:
       "Class methods cannot have the 'readonly' modifier.",
@@ -121,6 +124,12 @@ const TSErrors = makeErrorTemplates(
       "Private elements cannot have an accessibility modifier ('%0').",
     ReadonlyForMethodSignature:
       "'readonly' modifier can only appear on a property declaration or index signature.",
+    SetAccesorCannotHaveOptionalParameter:
+      "A 'set' accessor cannot have an optional parameter.",
+    SetAccesorCannotHaveRestParameter:
+      "A 'set' accessor cannot have rest parameter.",
+    SetAccesorCannotHaveReturnType:
+      "A 'set' accessor cannot have a return type annotation.",
     TypeAnnotationAfterAssign:
       "Type annotations must come before default assignments, e.g. instead of `age = 25: number` use `age: number = 25`.",
     TypeImportCannotSpecifyDefaultAndNamed:
@@ -192,12 +201,7 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       return this.match(tt.name);
     }
 
-    tsNextTokenCanFollowModifier() {
-      // Note: TypeScript's implementation is much more complicated because
-      // more things are considered modifiers there.
-      // This implementation only handles modifiers not handled by @babel/parser itself. And "static".
-      // TODO: Would be nice to avoid lookahead. Want a hasLineBreakUpNext() method...
-      this.next();
+    tsTokenCanFollowModifier() {
       return (
         (this.match(tt.bracketL) ||
           this.match(tt.braceL) ||
@@ -209,6 +213,15 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       );
     }
 
+    tsNextTokenCanFollowModifier() {
+      // Note: TypeScript's implementation is much more complicated because
+      // more things are considered modifiers there.
+      // This implementation only handles modifiers not handled by @babel/parser itself. And "static".
+      // TODO: Would be nice to avoid lookahead. Want a hasLineBreakUpNext() method...
+      this.next();
+      return this.tsTokenCanFollowModifier();
+    }
+
     /** Parses a modifier matching one the given modifier names. */
     tsParseModifier<T: TsModifier>(allowedModifiers: T[]): ?T {
       if (!this.match(tt.name)) {
@@ -546,8 +559,8 @@ export default (superClass: Class<Parser>): Class<Parser> =>
     }
 
     tsParseTypeMemberSemicolon(): void {
-      if (!this.eat(tt.comma)) {
-        this.semicolon();
+      if (!this.eat(tt.comma) && !this.isLineTerminator()) {
+        this.expect(tt.semi);
       }
     }
 
@@ -601,8 +614,57 @@ export default (superClass: Class<Parser>): Class<Parser> =>
           this.raise(node.start, TSErrors.ReadonlyForMethodSignature);
         }
         const method: N.TsMethodSignature = nodeAny;
+        if (method.kind && this.isRelational("<")) {
+          this.raise(this.state.pos, TSErrors.AccesorCannotHaveTypeParameters);
+        }
         this.tsFillSignature(tt.colon, method);
         this.tsParseTypeMemberSemicolon();
+        if (method.kind === "get") {
+          if (method.parameters.length > 0) {
+            this.raise(this.state.pos, Errors.BadGetterArity);
+            if (this.isThisParam(method.parameters[0])) {
+              this.raise(
+                this.state.pos,
+                TSErrors.AccesorCannotDeclareThisParameter,
+              );
+            }
+          }
+        } else if (method.kind === "set") {
+          if (method.parameters.length !== 1) {
+            this.raise(this.state.pos, Errors.BadSetterArity);
+          } else {
+            const firstParameter = method.parameters[0];
+            if (this.isThisParam(firstParameter)) {
+              this.raise(
+                this.state.pos,
+                TSErrors.AccesorCannotDeclareThisParameter,
+              );
+            }
+            if (
+              firstParameter.type === "Identifier" &&
+              firstParameter.optional
+            ) {
+              this.raise(
+                this.state.pos,
+                TSErrors.SetAccesorCannotHaveOptionalParameter,
+              );
+            }
+            if (firstParameter.type === "RestElement") {
+              this.raise(
+                this.state.pos,
+                TSErrors.SetAccesorCannotHaveRestParameter,
+              );
+            }
+          }
+          if (method.typeAnnotation) {
+            this.raise(
+              method.typeAnnotation.start,
+              TSErrors.SetAccesorCannotHaveReturnType,
+            );
+          }
+        } else {
+          method.kind = "method";
+        }
         return this.finishNode(method, "TSMethodSignature");
       } else {
         const property: N.TsPropertySignature = nodeAny;
@@ -656,6 +718,15 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       }
 
       this.parsePropertyName(node, /* isPrivateNameAllowed */ false);
+      if (
+        !node.computed &&
+        node.key.type === "Identifier" &&
+        (node.key.name === "get" || node.key.name === "set") &&
+        this.tsTokenCanFollowModifier()
+      ) {
+        node.kind = node.key.name;
+        this.parsePropertyName(node, /* isPrivateNameAllowed */ false);
+      }
       return this.tsParsePropertyOrMethodSignature(node, !!node.readonly);
     }
 

packages/babel-parser/src/types.js

@@ -1208,6 +1208,7 @@ export type TsPropertySignature = TsNamedTypeElementBase & {
 export type TsMethodSignature = TsSignatureDeclarationBase &
   TsNamedTypeElementBase & {
     type: "TSMethodSignature",
+    kind: "method" | "get" | "set",
   };
 
 // *Not* a ClassMemberBase: Can't have accessibility, can't be abstract, can't be optional.

packages/babel-parser/test/fixtures/typescript/declare/pattern-parameters/output.json

@@ -43,7 +43,8 @@
                   "type": "TSVoidKeyword",
                   "start":34,"end":38,"loc":{"start":{"line":2,"column":12},"end":{"line":2,"column":16}}
                 }
-              }
+              },
+              "kind": "method"
             },
             {
               "type": "TSMethodSignature",
@@ -74,7 +75,8 @@
                   "type": "TSAnyKeyword",
                   "start":56,"end":59,"loc":{"start":{"line":3,"column":16},"end":{"line":3,"column":19}}
                 }
-              }
+              },
+              "kind": "method"
             },
             {
               "type": "TSMethodSignature",
@@ -126,7 +128,8 @@
                   "type": "TSVoidKeyword",
                   "start":95,"end":99,"loc":{"start":{"line":4,"column":34},"end":{"line":4,"column":38}}
                 }
-              }
+              },
+              "kind": "method"
             }
           ]
         },

packages/babel-parser/test/fixtures/typescript/interface/get-set-ambiguous/input.ts

@@ -0,0 +1,6 @@
+interface Foo {
+  get
+  foo(): string;
+  set
+  bar(v);
+}

packages/babel-parser/test/fixtures/typescript/interface/get-set-ambiguous/output.json

@@ -0,0 +1,86 @@
+{
+  "type": "File",
+  "start":0,"end":56,"loc":{"start":{"line":1,"column":0},"end":{"line":6,"column":1}},
+  "program": {
+    "type": "Program",
+    "start":0,"end":56,"loc":{"start":{"line":1,"column":0},"end":{"line":6,"column":1}},
+    "sourceType": "module",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "TSInterfaceDeclaration",
+        "start":0,"end":56,"loc":{"start":{"line":1,"column":0},"end":{"line":6,"column":1}},
+        "id": {
+          "type": "Identifier",
+          "start":10,"end":13,"loc":{"start":{"line":1,"column":10},"end":{"line":1,"column":13},"identifierName":"Foo"},
+          "name": "Foo"
+        },
+        "body": {
+          "type": "TSInterfaceBody",
+          "start":14,"end":56,"loc":{"start":{"line":1,"column":14},"end":{"line":6,"column":1}},
+          "body": [
+            {
+              "type": "TSPropertySignature",
+              "start":18,"end":21,"loc":{"start":{"line":2,"column":2},"end":{"line":2,"column":5}},
+              "key": {
+                "type": "Identifier",
+                "start":18,"end":21,"loc":{"start":{"line":2,"column":2},"end":{"line":2,"column":5},"identifierName":"get"},
+                "name": "get"
+              },
+              "computed": false
+            },
+            {
+              "type": "TSMethodSignature",
+              "start":24,"end":38,"loc":{"start":{"line":3,"column":2},"end":{"line":3,"column":16}},
+              "key": {
+                "type": "Identifier",
+                "start":24,"end":27,"loc":{"start":{"line":3,"column":2},"end":{"line":3,"column":5},"identifierName":"foo"},
+                "name": "foo"
+              },
+              "computed": false,
+              "parameters": [],
+              "typeAnnotation": {
+                "type": "TSTypeAnnotation",
+                "start":29,"end":37,"loc":{"start":{"line":3,"column":7},"end":{"line":3,"column":15}},
+                "typeAnnotation": {
+                  "type": "TSStringKeyword",
+                  "start":31,"end":37,"loc":{"start":{"line":3,"column":9},"end":{"line":3,"column":15}}
+                }
+              },
+              "kind": "method"
+            },
+            {
+              "type": "TSPropertySignature",
+              "start":41,"end":44,"loc":{"start":{"line":4,"column":2},"end":{"line":4,"column":5}},
+              "key": {
+                "type": "Identifier",
+                "start":41,"end":44,"loc":{"start":{"line":4,"column":2},"end":{"line":4,"column":5},"identifierName":"set"},
+                "name": "set"
+              },
+              "computed": false
+            },
+            {
+              "type": "TSMethodSignature",
+              "start":47,"end":54,"loc":{"start":{"line":5,"column":2},"end":{"line":5,"column":9}},
+              "key": {
+                "type": "Identifier",
+                "start":47,"end":50,"loc":{"start":{"line":5,"column":2},"end":{"line":5,"column":5},"identifierName":"bar"},
+                "name": "bar"
+              },
+              "computed": false,
+              "parameters": [
+                {
+                  "type": "Identifier",
+                  "start":51,"end":52,"loc":{"start":{"line":5,"column":6},"end":{"line":5,"column":7},"identifierName":"v"},
+                  "name": "v"
+                }
+              ],
+              "kind": "method"
+            }
+          ]
+        }
+      }
+    ],
+    "directives": []
+  }
+}

packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-optional-parameter/input.ts

@@ -0,0 +1,3 @@
+interface Foo {
+  set bar(foo?: string);
+}

packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-optional-parameter/output.json

@@ -0,0 +1,58 @@
+{
+  "type": "File",
+  "start":0,"end":42,"loc":{"start":{"line":1,"column":0},"end":{"line":3,"column":1}},
+  "errors": [
+    "SyntaxError: A 'set' accessor cannot have an optional parameter. (3:1)"
+  ],
+  "program": {
+    "type": "Program",
+    "start":0,"end":42,"loc":{"start":{"line":1,"column":0},"end":{"line":3,"column":1}},
+    "sourceType": "module",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "TSInterfaceDeclaration",
+        "start":0,"end":42,"loc":{"start":{"line":1,"column":0},"end":{"line":3,"column":1}},
+        "id": {
+          "type": "Identifier",
+          "start":10,"end":13,"loc":{"start":{"line":1,"column":10},"end":{"line":1,"column":13},"identifierName":"Foo"},
+          "name": "Foo"
+        },
+        "body": {
+          "type": "TSInterfaceBody",
+          "start":14,"end":42,"loc":{"start":{"line":1,"column":14},"end":{"line":3,"column":1}},
+          "body": [
+            {
+              "type": "TSMethodSignature",
+              "start":18,"end":40,"loc":{"start":{"line":2,"column":2},"end":{"line":2,"column":24}},
+              "key": {
+                "type": "Identifier",
+                "start":22,"end":25,"loc":{"start":{"line":2,"column":6},"end":{"line":2,"column":9},"identifierName":"bar"},
+                "name": "bar"
+              },
+              "computed": false,
+              "kind": "set",
+              "parameters": [
+                {
+                  "type": "Identifier",
+                  "start":26,"end":38,"loc":{"start":{"line":2,"column":10},"end":{"line":2,"column":22},"identifierName":"foo"},
+                  "name": "foo",
+                  "optional": true,
+                  "typeAnnotation": {
+                    "type": "TSTypeAnnotation",
+                    "start":30,"end":38,"loc":{"start":{"line":2,"column":14},"end":{"line":2,"column":22}},
+                    "typeAnnotation": {
+                      "type": "TSStringKeyword",
+                      "start":32,"end":38,"loc":{"start":{"line":2,"column":16},"end":{"line":2,"column":22}}
+                    }
+                  }
+                }
+              ]
+            }
+          ]
+        }
+      }
+    ],
+    "directives": []
+  }
+}

packages/babel-parser/test/fixtures/typescript/interface/get-set-invalid-parameters/input.ts

@@ -0,0 +1,4 @@
+interface Foo {
+  get foo(param): string;
+  set foo();
+}