Decorators misc fixes (#14339)

* fix: ensure initializer is invoked without parameters

* fix: assert class decorators return a callable or undefined

* fix: accessor decorator returns { initialize?: (initialValue: unknown) => unknown };

* fix: assert accessor decorator returns callable get/set/initialize

* add getter/setter test cases

* add accessor-initializers ordering test

* address review comments

* remove unused param base

* add leaked context addInitializer test

packages/babel-helpers/src/helpers/applyDecs.js

@@ -14,6 +14,8 @@
   SETTER = 4;
 
   STATIC = 5;
+
+  CLASS = 10; // only used in assertValidReturnValue
 */
 
 function createMetadataMethodsForProperty(metadataMap, kind, property) {
@@ -120,13 +122,12 @@ function convertMetadataMapToFinal(obj, metadataMap) {
 
 function createAddInitializerMethod(initializers) {
   return function addInitializer(initializer) {
-    assertValidInitializer(initializer);
+    assertCallable(initializer, "An initializer");
     initializers.push(initializer);
   };
 }
 
 function memberDecCtx(
-  base,
   name,
   desc,
   metadataMap,
@@ -207,9 +208,9 @@ function memberDecCtx(
   );
 }
 
-function assertValidInitializer(initializer) {
-  if (typeof initializer !== "function") {
-    throw new Error("initializers must be functions");
+function assertCallable(fn, hint) {
+  if (typeof fn !== "function") {
+    throw new TypeError(hint + " must be a function");
   }
 }
 
@@ -218,18 +219,29 @@ function assertValidReturnValue(kind, value) {
 
   if (kind === 1 /* ACCESSOR */) {
     if (type !== "object" || value === null) {
-      throw new Error(
+      throw new TypeError(
         "accessor decorators must return an object with get, set, or initializer properties or void 0"
       );
     }
+    if (value.get !== undefined) {
+      assertCallable(value.get, "accessor.get");
+    }
+    if (value.set !== undefined) {
+      assertCallable(value.set, "accessor.set");
+    }
+    if (value.initialize !== undefined) {
+      assertCallable(value.initialize, "accessor.initialize");
+    }
   } else if (type !== "function") {
+    var hint;
     if (kind === 0 /* FIELD */) {
-      throw new Error(
-        "field decorators must return a initializer function or void 0"
-      );
+      hint = "field";
+    } else if (kind === 10 /* CLASS */) {
+      hint = "class";
     } else {
-      throw new Error("method decorators must return a function or void 0");
+      hint = "method";
     }
+    throw new TypeError(hint + " decorators must return a function or void 0");
   }
 }
 
@@ -285,7 +297,6 @@ function applyMemberDec(
   }
 
   var ctx = memberDecCtx(
-    base,
     name,
     desc,
     metadataMap,
@@ -306,7 +317,7 @@ function applyMemberDec(
       if (kind === 0 /* FIELD */) {
         initializer = newValue;
       } else if (kind === 1 /* ACCESSOR */) {
-        initializer = newValue.initializer;
+        initializer = newValue.initialize;
 
         get = newValue.get || value.get;
         set = newValue.set || value.set;
@@ -329,7 +340,7 @@ function applyMemberDec(
         if (kind === 0 /* FIELD */) {
           newInit = newValue;
         } else if (kind === 1 /* ACCESSOR */) {
-          newInit = newValue.initializer;
+          newInit = newValue.initialize;
 
           get = newValue.get || value.get;
           set = newValue.set || value.set;
@@ -510,7 +521,7 @@ function pushInitializers(ret, initializers) {
 
       ret.push(function (instance) {
         for (var i = 0; i < initializers.length; i++) {
-          initializers[i].call(instance, instance);
+          initializers[i].call(instance);
         }
         return instance;
       });
@@ -538,15 +549,19 @@ function applyClassDecs(ret, targetClass, metadataMap, classDecs) {
     );
 
     for (var i = classDecs.length - 1; i >= 0; i--) {
-      newClass = classDecs[i](newClass, ctx) || newClass;
+      var nextNewClass = classDecs[i](newClass, ctx);
+      if (nextNewClass !== undefined) {
+        assertValidReturnValue(10 /* CLASS */, nextNewClass);
+        newClass = nextNewClass;
+      }
     }
 
     ret.push(newClass);
 
     if (initializers.length > 0) {
       ret.push(function () {
         for (var i = 0; i < initializers.length; i++) {
-          initializers[i].call(newClass, newClass);
+          initializers[i].call(newClass);
         }
       });
     } else {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-accessors--to-es2015/private/exec.js

@@ -1,6 +1,6 @@
 function dec({ get, set }, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + 'Context'] = context;
   });
 
   return {
@@ -12,7 +12,7 @@ function dec({ get, set }, context) {
       set.call(this, v + 1);
     },
 
-    initializer(v) {
+    initialize(v) {
       return v ? v : 1;
     }
   }

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-accessors--to-es2015/public/exec.js

@@ -1,6 +1,6 @@
 function dec({ get, set }, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + 'Context'] = context;
   });
 
   return {
@@ -12,7 +12,7 @@ function dec({ get, set }, context) {
       set.call(this, v + 1);
     },
 
-    initializer(v) {
+    initialize(v) {
       return v ? v : 1;
     }
   }

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-accessors--to-es2015/static-private/exec.js

@@ -1,6 +1,6 @@
 function dec({ get, set }, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + 'Context'] = context;
   });
 
   return {
@@ -12,7 +12,7 @@ function dec({ get, set }, context) {
       set.call(this, v + 1);
     },
 
-    initializer(v) {
+    initialize(v) {
       return v ? v : 1;
     }
   }

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-accessors--to-es2015/static-public/exec.js

@@ -1,6 +1,6 @@
 function dec({ get, set }, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + 'Context'] = context;
   });
 
   return {
@@ -12,7 +12,7 @@ function dec({ get, set }, context) {
       set.call(this, v + 1);
     },
 
-    initializer(v) {
+    initialize(v) {
       return v ? v : 1;
     }
   }

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-getters--to-es2015/private/exec.js

@@ -1,6 +1,6 @@
 function dec(get, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + 'Context'] = context;
   });
 
   return function () {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-getters--to-es2015/public/exec.js

@@ -1,6 +1,6 @@
 function dec(get, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + 'Context'] = context;
   });
 
   return function () {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-getters--to-es2015/static-private/exec.js

@@ -1,6 +1,6 @@
 function dec(get, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + 'Context'] = context;
   });
 
   return function () {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-getters--to-es2015/static-public/exec.js

@@ -1,6 +1,6 @@
 function dec(get, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + 'Context'] = context;
   });
 
   return function () {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-getters-and-setters--to-es2015/private/exec.js

@@ -1,6 +1,6 @@
 function dec(value, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + '_' + context.kind + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + '_' + context.kind + 'Context'] = context;
   });
 
   if (context.kind === 'getter') {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-getters-and-setters--to-es2015/public/exec.js

@@ -1,6 +1,6 @@
 function dec(value, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + '_' + context.kind + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + '_' + context.kind + 'Context'] = context;
   });
 
   if (context.kind === 'getter') {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-getters-and-setters--to-es2015/static-private/exec.js

@@ -1,6 +1,6 @@
 function dec(value, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + '_' + context.kind + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + '_' + context.kind + 'Context'] = context;
   });
 
   if (context.kind === 'getter') {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-getters-and-setters--to-es2015/static-public/exec.js

@@ -1,6 +1,6 @@
 function dec(value, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + '_' + context.kind + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + '_' + context.kind + 'Context'] = context;
   });
 
   if (context.kind === 'getter') {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-methods--to-es2015/private-with-initializers/exec.js

@@ -1,6 +1,6 @@
 function dec(fn, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + 'Context'] = context;
   });
 
   return function () {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-methods--to-es2015/public-with-initializers/exec.js

@@ -1,6 +1,6 @@
 function dec(fn, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + 'Context'] = context;
   });
 
   return function () {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-methods--to-es2015/static-private-with-initializers/exec.js

@@ -1,6 +1,6 @@
 function dec(fn, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + 'Context'] = context;
   });
 
   return function () {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-methods--to-es2015/static-public-with-initializers/exec.js

@@ -1,6 +1,6 @@
 function dec(fn, context) {
-  context.addInitializer((instance) => {
-    instance[context.name + 'Context'] = context;
+  context.addInitializer(function() {
+    this[context.name + 'Context'] = context;
   });
 
   return function () {

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-misc--to-es2015/leaked-proto-context-addInitializer/exec.js

@@ -0,0 +1,21 @@
+let addInitializer, i = 0;
+const logs = [];
+
+function decCallProtoAddInitializer() {
+  addInitializer(() => logs.push(i++));
+}
+
+function decMethod(_, context) {
+  ({ addInitializer } = context);
+  addInitializer(() => logs.push(i++));
+}
+
+@decCallProtoAddInitializer
+class C {
+  @decMethod m() {}
+  @decCallProtoAddInitializer static n() {}
+}
+
+new C;
+
+expect(logs).toEqual([0, 1]);

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-misc--to-es2015/leaked-static-context-addInitializer/exec.js

@@ -0,0 +1,21 @@
+let addInitializer, i = 0;
+const logs = [];
+
+function decCallStaticAddInitializer() {
+  addInitializer(() => logs.push(i++));
+}
+
+function decStaticMethod(_, context) {
+  ({ addInitializer } = context);
+  addInitializer(() => logs.push(i++));
+}
+
+@decCallStaticAddInitializer
+class C {
+  @decStaticMethod static m() {}
+  @decCallStaticAddInitializer n() {}
+}
+
+new C;
+
+expect(logs).toEqual([0, 1]);

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-ordering--to-es2015/accessor-initializers/exec.js

@@ -0,0 +1,46 @@
+var log = [];
+
+function push(x) { log.push(x); return x; }
+
+function logClassDecoratorRun(a, b, c) {
+  push(a);
+  return function (el, { addInitializer }) {
+    push(b);
+    addInitializer(function () { push(c); });
+    return el;
+  };
+}
+
+function logAccessorDecoratorRun(a, b, c, d) {
+  push(a);
+  return function (el, { addInitializer }) {
+    push(b);
+    addInitializer(function () { push(c); });
+    return {
+      initialize: () => push(d)
+    };
+  };
+}
+
+@logClassDecoratorRun(0, 19, 29)
+@logClassDecoratorRun(1, 18, 28)
+class A {
+  @logAccessorDecoratorRun(2, 11)
+  @logAccessorDecoratorRun(3, 10)
+  accessor a;
+
+  @logAccessorDecoratorRun(4, 13, 21, 25)
+  @logAccessorDecoratorRun(5, 12, 20, 24)
+  static accessor b;
+
+  @logAccessorDecoratorRun(6, 15, 23, 27)
+  @logAccessorDecoratorRun(7, 14, 22, 26)
+  static accessor #c;
+
+  @logAccessorDecoratorRun(8, 17)
+  @logAccessorDecoratorRun(9, 16)
+  accessor #d;
+}
+
+var nums = Array.from({ length: 30 }, (_, i) => i);
+expect(log).toEqual(nums);