Allow context type annotation on getters/setters

babel · Mar 6, 2019 · 238598c · 238598c
1 parent 349c0d4
commit 238598c
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Showing 5 changed files with 429 additions and 2 deletions.
diff --git a/packages/babel-parser/src/parser/expression.js b/packages/babel-parser/src/parser/expression.js
@@ -1552,15 +1552,25 @@ export default class ExpressionParser extends LValParser {
   checkGetterSetterParams(method: N.ObjectMethod | N.ClassMethod): void {
     const paramCount = method.kind === "get" ? 0 : 1;
     const start = method.start;
-    if (method.params.length !== paramCount) {
+    // Allow `this` type annotation in TypeScript
+    if (
+      method.params.length === paramCount + 1 &&
+      method.params[0].type === "Identifier" &&
+      method.params[0].name === "this"
+    ) {
+      this.expectPlugin("typescript");
+    } else if (method.params.length !== paramCount) {
       if (method.kind === "get") {
         this.raise(start, "getter must not have any formal parameters");
       } else {
         this.raise(start, "setter must have exactly one formal parameter");
       }
     }
 
-    if (method.kind === "set" && method.params[0].type === "RestElement") {
+    if (
+      method.kind === "set" &&
+      method.params[method.params.length - 1].type === "RestElement"
+    ) {
       this.raise(
         start,
         "setter function argument must not be a rest parameter",

diff --git a/packages/babel-parser/test/fixtures/typescript/function/getter-setter/input.js b/packages/babel-parser/test/fixtures/typescript/function/getter-setter/input.js
@@ -0,0 +1,6 @@
+const g = {
+  get m(this: {}) {}
+};
+const s = {
+  set m(this: {}, value) {}
+};