[decorators] Support async and generator methods (#8742)

packages/babel-plugin-proposal-decorators/src/transformer.js

@@ -7,8 +7,11 @@ function prop(key, value) {
   return t.objectProperty(t.identifier(key), value);
 }
 
-function value(body, params = []) {
+function value(body, params = [], async, generator) {
-  return t.objectMethod("method", t.identifier("value"), params, body);
+  const method = t.objectMethod("method", t.identifier("value"), params, body);
+  method.async = !!async;
+  method.generator = !!generator;
+  return method;
 }
 
 function hasDecorators({ node }) {
@@ -77,7 +80,7 @@ function getSingleElementDefinition(path, superRef, classRef, file) {
     prop("static", node.static && t.booleanLiteral(true)),
     prop("key", getKey(node)),
     isMethod
-      ? value(node.body, node.params)
+      ? value(node.body, node.params, node.async, node.generator)
       : node.value
         ? value(template.ast`{ return ${node.value} }`)
         : prop("value", scope.buildUndefinedNode()),

packages/babel-plugin-proposal-decorators/test/fixtures/transformation/async-generator-method/input.js

@@ -0,0 +1,8 @@
+@decorator
+class Foo {
+  async f1() {}
+
+  *f2() {}
+
+  async *f3() {}
+}

packages/babel-plugin-proposal-decorators/test/fixtures/transformation/async-generator-method/options.json

@@ -0,0 +1,8 @@
+{
+  "plugins": [
+    ["proposal-decorators", { "decoratorsBeforeExport": false }],
+    "proposal-class-properties",
+    "syntax-async-generators",
+    ["external-helpers", { "helperVersion": "7.0.2" }]
+  ]
+}

packages/babel-plugin-proposal-decorators/test/fixtures/transformation/async-generator-method/output.js

@@ -0,0 +1,33 @@
+let Foo = babelHelpers.decorate([decorator], function (_initialize) {
+  "use strict";
+
+  class Foo {
+    constructor() {
+      _initialize(this);
+    }
+
+  }
+
+  return {
+    F: Foo,
+    d: [{
+      kind: "method",
+      key: "f1",
+
+      async value() {}
+
+    }, {
+      kind: "method",
+      key: "f2",
+
+      *value() {}
+
+    }, {
+      kind: "method",
+      key: "f3",
+
+      async *value() {}
+
+    }]
+  };
+});