Update decorators to match latest spec

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

@@ -18,12 +18,16 @@
   CLASS = 10; // only used in assertValidReturnValue
 */
 
-function createMetadataMethodsForProperty(metadataMap, kind, property) {
+function createMetadataMethodsForProperty(
+  metadataMap,
+  kind,
+  property,
+  decoratorFinishedRef
+) {
   return {
     getMetadata: function (key) {
-      if (typeof key !== "symbol") {
-        throw new TypeError("Metadata keys must be symbols, received: " + key);
-      }
+      assertNotFinished(decoratorFinishedRef, "getMetadata");
+      assertMetadataKey(key);
 
       var metadataForKey = metadataMap[key];
 
@@ -44,9 +48,8 @@ function createMetadataMethodsForProperty(metadataMap, kind, property) {
       }
     },
     setMetadata: function (key, value) {
-      if (typeof key !== "symbol") {
-        throw new TypeError("Metadata keys must be symbols, received: " + key);
-      }
+      assertNotFinished(decoratorFinishedRef, "setMetadata");
+      assertMetadataKey(key);
 
       var metadataForKey = metadataMap[key];
 
@@ -120,21 +123,24 @@ function convertMetadataMapToFinal(obj, metadataMap) {
   obj[Symbol.metadata || Symbol.for("Symbol.metadata")] = metadataMap;
 }
 
-function createAddInitializerMethod(initializers) {
+function createAddInitializerMethod(initializers, decoratorFinishedRef) {
   return function addInitializer(initializer) {
+    assertNotFinished(decoratorFinishedRef, "addInitializer");
     assertCallable(initializer, "An initializer");
     initializers.push(initializer);
   };
 }
 
-function memberDecCtx(
+function memberDec(
+  dec,
   name,
   desc,
   metadataMap,
   initializers,
   kind,
   isStatic,
-  isPrivate
+  isPrivate,
+  value
 ) {
   var kindStr;
 
@@ -162,8 +168,13 @@ function memberDecCtx(
     isPrivate: isPrivate,
   };
 
+  var decoratorFinishedRef = { v: false };
+
   if (kind !== 0 /* FIELD */) {
-    ctx.addInitializer = createAddInitializerMethod(initializers);
+    ctx.addInitializer = createAddInitializerMethod(
+      initializers,
+      decoratorFinishedRef
+    );
   }
 
   var metadataKind, metadataName;
@@ -202,10 +213,36 @@ function memberDecCtx(
     metadataName = name;
   }
 
-  return Object.assign(
-    ctx,
-    createMetadataMethodsForProperty(metadataMap, metadataKind, metadataName)
-  );
+  try {
+    return dec(
+      value,
+      Object.assign(
+        ctx,
+        createMetadataMethodsForProperty(
+          metadataMap,
+          metadataKind,
+          metadataName,
+          decoratorFinishedRef
+        )
+      )
+    );
+  } finally {
+    decoratorFinishedRef.v = true;
+  }
+}
+
+function assertNotFinished(decoratorFinishedRef, fnName) {
+  if (decoratorFinishedRef.v) {
+    throw new Error(
+      "attempted to call " + fnName + " after decoration was finished"
+    );
+  }
+}
+
+function assertMetadataKey(key) {
+  if (typeof key !== "symbol") {
+    throw new TypeError("Metadata keys must be symbols, received: " + key);
+  }
 }
 
 function assertCallable(fn, hint) {
@@ -220,7 +257,7 @@ function assertValidReturnValue(kind, value) {
   if (kind === 1 /* ACCESSOR */) {
     if (type !== "object" || value === null) {
       throw new TypeError(
-        "accessor decorators must return an object with get, set, or initializer properties or void 0"
+        "accessor decorators must return an object with get, set, or init properties or void 0"
       );
     }
     if (value.get !== undefined) {
@@ -229,8 +266,11 @@ function assertValidReturnValue(kind, value) {
     if (value.set !== undefined) {
       assertCallable(value.set, "accessor.set");
     }
-    if (value.initialize !== undefined) {
-      assertCallable(value.initialize, "accessor.initialize");
+    if (value.init !== undefined) {
+      assertCallable(value.init, "accessor.init");
+    }
+    if (value.initializer !== undefined) {
+      assertCallable(value.initializer, "accessor.initializer");
     }
   } else if (type !== "function") {
     var hint;
@@ -296,28 +336,36 @@ function applyMemberDec(
     value = desc.set;
   }
 
-  var ctx = memberDecCtx(
-    name,
-    desc,
-    metadataMap,
-    initializers,
-    kind,
-    isStatic,
-    isPrivate
-  );
-
   var newValue, get, set;
 
   if (typeof decs === "function") {
-    newValue = decs(value, ctx);
+    newValue = memberDec(
+      decs,
+      name,
+      desc,
+      metadataMap,
+      initializers,
+      kind,
+      isStatic,
+      isPrivate,
+      value
+    );
 
     if (newValue !== void 0) {
       assertValidReturnValue(kind, newValue);
 
       if (kind === 0 /* FIELD */) {
         initializer = newValue;
       } else if (kind === 1 /* ACCESSOR */) {
-        initializer = newValue.initialize;
+        if (
+          (initializer = newValue.init) == null &&
+          (initializer = newValue.initializer) &&
+          typeof console !== "undefined"
+        ) {
+          console.warn(
+            ".initializer has been renamed to .init as of March 2022"
+          );
+        }
 
         get = newValue.get || value.get;
         set = newValue.set || value.set;
@@ -331,7 +379,17 @@ function applyMemberDec(
     for (var i = decs.length - 1; i >= 0; i--) {
       var dec = decs[i];
 
-      newValue = dec(value, ctx);
+      newValue = memberDec(
+        dec,
+        name,
+        desc,
+        metadataMap,
+        initializers,
+        kind,
+        isStatic,
+        isPrivate,
+        value
+      );
 
       if (newValue !== void 0) {
         assertValidReturnValue(kind, newValue);
@@ -340,7 +398,15 @@ function applyMemberDec(
         if (kind === 0 /* FIELD */) {
           newInit = newValue;
         } else if (kind === 1 /* ACCESSOR */) {
-          newInit = newValue.initialize;
+          if (
+            (newInit = newValue.init) == null &&
+            (newInit = newValue.initializer) &&
+            typeof console !== "undefined"
+          ) {
+            console.warn(
+              ".initializer has been renamed to .init as of March 2022"
+            );
+          }
 
           get = newValue.get || value.get;
           set = newValue.set || value.set;
@@ -537,19 +603,33 @@ function applyClassDecs(ret, targetClass, metadataMap, classDecs) {
   if (classDecs.length > 0) {
     var initializers = [];
     var newClass = targetClass;
-
     var name = targetClass.name;
-    var ctx = Object.assign(
-      {
-        kind: "class",
-        name: name,
-        addInitializer: createAddInitializerMethod(initializers),
-      },
-      createMetadataMethodsForProperty(metadataMap, 0 /* CONSTRUCTOR */, name)
-    );
 
     for (var i = classDecs.length - 1; i >= 0; i--) {
-      var nextNewClass = classDecs[i](newClass, ctx);
+      var decoratorFinishedRef = { v: false };
+
+      try {
+        var ctx = Object.assign(
+          {
+            kind: "class",
+            name: name,
+            addInitializer: createAddInitializerMethod(
+              initializers,
+              decoratorFinishedRef
+            ),
+          },
+          createMetadataMethodsForProperty(
+            metadataMap,
+            0 /* CONSTRUCTOR */,
+            name,
+            decoratorFinishedRef
+          )
+        );
+        var nextNewClass = classDecs[i](newClass, ctx);
+      } finally {
+        decoratorFinishedRef.v = true;
+      }
+
       if (nextNewClass !== undefined) {
         assertValidReturnValue(10 /* CLASS */, nextNewClass);
         newClass = nextNewClass;

packages/babel-plugin-proposal-decorators/src/transformer-2021-12.ts

@@ -311,11 +311,28 @@ function isDecoratorInfo(
   return "decorators" in info;
 }
 
+function filteredOrderedDecoratorInfo(
+  info: (DecoratorInfo | ComputedPropInfo)[],
+): DecoratorInfo[] {
+  const filtered = info.filter(isDecoratorInfo);
+
+  return [
+    ...filtered.filter(
+      el => el.isStatic && el.kind >= ACCESSOR && el.kind <= SETTER,
+    ),
+    ...filtered.filter(
+      el => !el.isStatic && el.kind >= ACCESSOR && el.kind <= SETTER,
+    ),
+    ...filtered.filter(el => el.isStatic && el.kind === FIELD),
+    ...filtered.filter(el => !el.isStatic && el.kind === FIELD),
+  ];
+}
+
 function generateDecorationExprs(
   info: (DecoratorInfo | ComputedPropInfo)[],
 ): t.ArrayExpression {
   return t.arrayExpression(
-    info.filter(isDecoratorInfo).map(el => {
+    filteredOrderedDecoratorInfo(info).map(el => {
       const decs =
         el.decorators.length > 1
           ? t.arrayExpression(el.decorators)
@@ -341,19 +358,19 @@ function generateDecorationExprs(
 function extractElementLocalAssignments(
   decorationInfo: (DecoratorInfo | ComputedPropInfo)[],
 ) {
-  const locals: t.Identifier[] = [];
+  const localIds: t.Identifier[] = [];
 
-  for (const el of decorationInfo) {
-    if ("locals" in el && el.locals) {
-      if (Array.isArray(el.locals)) {
-        locals.push(...el.locals);
-      } else {
-        locals.push(el.locals);
-      }
+  for (const el of filteredOrderedDecoratorInfo(decorationInfo)) {
+    const { locals } = el;
+
+    if (Array.isArray(locals)) {
+      localIds.push(...locals);
+    } else if (locals !== undefined) {
+      localIds.push(locals);
     }
   }
 
-  return locals;
+  return localIds;
 }
 
 function addCallAccessorsFor(

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

@@ -12,7 +12,7 @@ function dec({ get, set }, context) {
       set.call(this, v + 1);
     },
 
-    initialize(v) {
+    init(v) {
       return v ? v : 1;
     }
   }

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

@@ -12,7 +12,7 @@ function dec({ get, set }, context) {
       set.call(this, v + 1);
     },
 
-    initialize(v) {
+    init(v) {
       return v ? v : 1;
     }
   }

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

@@ -12,7 +12,7 @@ function dec({ get, set }, context) {
       set.call(this, v + 1);
     },
 
-    initialize(v) {
+    init(v) {
       return v ? v : 1;
     }
   }

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

@@ -12,7 +12,7 @@ function dec({ get, set }, context) {
       set.call(this, v + 1);
     },
 
-    initialize(v) {
+    init(v) {
       return v ? v : 1;
     }
   }

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-duplicated-keys--to-es2015/method-and-field/exec.js

@@ -17,7 +17,7 @@ class Foo {
 expect(elements).toHaveLength(2);
 
 expect(elements[0].context.name).toBe("a");
-expect(elements[0].val).toBe(undefined);
+expect(elements[0].val()).toBe(1);
 
 expect(elements[1].context.name).toBe("a");
-expect(elements[1].val()).toBe(1);
+expect(elements[1].val).toBe(undefined);

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-duplicated-keys--to-es2015/method-and-field/output.js

@@ -13,4 +13,4 @@ class Foo {
 
 }
 
-[_init_a, _initProto] = babelHelpers.applyDecs(Foo, [[dec, 0, "a"], [dec, 2, "a"]], []);
+[_init_a, _initProto] = babelHelpers.applyDecs(Foo, [[dec, 2, "a"], [dec, 0, "a"]], []);

packages/babel-plugin-proposal-decorators/test/fixtures/2021-12-duplicated-keys/method-and-field/output.js

@@ -4,7 +4,7 @@ const dec = () => {};
 
 class Foo {
   static {
-    [_init_a, _initProto] = babelHelpers.applyDecs(this, [[dec, 0, "a"], [dec, 2, "a"]], []);
+    [_init_a, _initProto] = babelHelpers.applyDecs(this, [[dec, 2, "a"], [dec, 0, "a"]], []);
   }
   a = (_initProto(this), _init_a(this, 123));