Implement noUninitializedPrivateFieldAccess assumption (#16267)

babel · Feb 26, 2024 · 3c0abc7 · 3c0abc7
1 parent cb4d920
commit 3c0abc7
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Showing 9 changed files with 138 additions and 19 deletions.
diff --git a/packages/babel-core/src/config/validation/options.ts b/packages/babel-core/src/config/validation/options.ts
@@ -281,6 +281,7 @@ const knownAssumptions = [
   "noDocumentAll",
   "noIncompleteNsImportDetection",
   "noNewArrows",
+  "noUninitializedPrivateFieldAccess",
   "objectRestNoSymbols",
   "privateFieldsAsSymbols",
   "privateFieldsAsProperties",

diff --git a/packages/babel-helper-create-class-features-plugin/src/fields.ts b/packages/babel-helper-create-class-features-plugin/src/fields.ts
@@ -167,9 +167,7 @@ export function privateNameVisitorFactory<S, V>(
   // Traverses the outer portion of a class, without touching the class's inner
   // scope, for private names.
   const nestedVisitor = traverse.visitors.merge([
-    {
-      ...visitor,
-    },
+    { ...visitor },
     environmentVisitor,
   ]);
 
@@ -224,6 +222,7 @@ interface PrivateNameState {
   classRef: t.Identifier;
   file: File;
   noDocumentAll: boolean;
+  noUninitializedPrivateFieldAccess: boolean;
   innerBinding?: t.Identifier;
 }
 
@@ -361,6 +360,14 @@ function writeOnlyError(file: File, name: string) {
   ]);
 }
 
+function buildStaticPrivateFieldAccess<N extends t.Expression>(
+  expr: N,
+  noUninitializedPrivateFieldAccess: boolean,
+) {
+  if (noUninitializedPrivateFieldAccess) return expr;
+  return t.memberExpression(expr, t.identifier("_"));
+}
+
 const privateNameHandlerSpec: Handler<PrivateNameState & Receiver> & Receiver =
   {
     memoise(member, count) {
@@ -386,7 +393,13 @@ const privateNameHandlerSpec: Handler<PrivateNameState & Receiver> & Receiver =
     },
 
     get(member) {
-      const { classRef, privateNamesMap, file, innerBinding } = this;
+      const {
+        classRef,
+        privateNamesMap,
+        file,
+        innerBinding,
+        noUninitializedPrivateFieldAccess,
+      } = this;
       const { name } = (member.node.property as t.PrivateName).id;
       const {
         id,
@@ -424,16 +437,19 @@ const privateNameHandlerSpec: Handler<PrivateNameState & Receiver> & Receiver =
 
         if (!isMethod) {
           if (skipCheck) {
-            return t.memberExpression(t.cloneNode(id), t.identifier("_"));
+            return buildStaticPrivateFieldAccess(
+              t.cloneNode(id),
+              noUninitializedPrivateFieldAccess,
+            );
           }
 
-          return t.memberExpression(
+          return buildStaticPrivateFieldAccess(
             t.callExpression(file.addHelper("assertClassBrand"), [
               receiver,
               t.cloneNode(classRef),
               t.cloneNode(id),
             ]),
-            t.identifier("_"),
+            noUninitializedPrivateFieldAccess,
           );
         }
 
@@ -515,7 +531,12 @@ const privateNameHandlerSpec: Handler<PrivateNameState & Receiver> & Receiver =
     },
 
     set(member, value) {
-      const { classRef, privateNamesMap, file } = this;
+      const {
+        classRef,
+        privateNamesMap,
+        file,
+        noUninitializedPrivateFieldAccess,
+      } = this;
       const { name } = (member.node.property as t.PrivateName).id;
       const {
         id,
@@ -574,7 +595,10 @@ const privateNameHandlerSpec: Handler<PrivateNameState & Receiver> & Receiver =
         }
         return t.assignmentExpression(
           "=",
-          t.memberExpression(t.cloneNode(id), t.identifier("_")),
+          buildStaticPrivateFieldAccess(
+            t.cloneNode(id),
+            noUninitializedPrivateFieldAccess,
+          ),
           skipCheck
             ? value
             : t.callExpression(file.addHelper("assertClassBrand"), [
@@ -615,7 +639,12 @@ const privateNameHandlerSpec: Handler<PrivateNameState & Receiver> & Receiver =
     },
 
     destructureSet(member) {
-      const { classRef, privateNamesMap, file } = this;
+      const {
+        classRef,
+        privateNamesMap,
+        file,
+        noUninitializedPrivateFieldAccess,
+      } = this;
       const { name } = (member.node.property as t.PrivateName).id;
       const {
         id,
@@ -669,7 +698,19 @@ const privateNameHandlerSpec: Handler<PrivateNameState & Receiver> & Receiver =
       }
 
       if (isStatic && !isMethod) {
-        return this.get(member);
+        const getCall = this.get(member);
+        if (
+          !noUninitializedPrivateFieldAccess ||
+          !t.isCallExpression(getCall)
+        ) {
+          return getCall;
+        }
+        const ref = getCall.arguments.pop();
+        getCall.arguments.push(template.expression.ast`(_) => ${ref} = _`);
+        return t.memberExpression(
+          t.callExpression(file.addHelper("toSetter"), [getCall]),
+          t.identifier("_"),
+        );
       }
 
       const setCall = this.set(member, t.identifier("_"));
@@ -793,10 +834,12 @@ export function transformPrivateNamesUsage(
   privateNamesMap: PrivateNamesMap,
   {
     privateFieldsAsProperties,
+    noUninitializedPrivateFieldAccess,
     noDocumentAll,
     innerBinding,
   }: {
     privateFieldsAsProperties: boolean;
+    noUninitializedPrivateFieldAccess: boolean;
     noDocumentAll: boolean;
     innerBinding: t.Identifier;
   },
@@ -815,6 +858,7 @@ export function transformPrivateNamesUsage(
     file: state,
     ...handler,
     noDocumentAll,
+    noUninitializedPrivateFieldAccess,
     innerBinding,
   });
   body.traverse(privateInVisitor, {
@@ -888,14 +932,20 @@ function buildPrivateInstanceFieldInitSpec(
 function buildPrivateStaticFieldInitSpec(
   prop: NodePath<t.ClassPrivateProperty>,
   privateNamesMap: PrivateNamesMap,
+  noUninitializedPrivateFieldAccess: boolean,
 ) {
   const privateName = privateNamesMap.get(prop.node.key.id.name);
-  return inheritPropComments(
-    template.statement.ast`
-      var ${t.cloneNode(privateName.id)} = {
+
+  const value = noUninitializedPrivateFieldAccess
+    ? prop.node.value
+    : template.expression.ast`{
         _: ${prop.node.value || t.buildUndefinedNode()}
-      };
-    `,
+      }`;
+
+  return inheritPropComments(
+    t.variableDeclaration("var", [
+      t.variableDeclarator(t.cloneNode(privateName.id), value),
+    ]),
     prop,
   );
 }
@@ -1368,6 +1418,7 @@ export function buildFieldsInitNodes(
   file: File,
   setPublicClassFields: boolean,
   privateFieldsAsProperties: boolean,
+  noUninitializedPrivateFieldAccess: boolean,
   constantSuper: boolean,
   innerBindingRef: t.Identifier | null,
 ) {
@@ -1473,7 +1524,11 @@ export function buildFieldsInitNodes(
           );
         } else {
           staticNodes.push(
-            buildPrivateStaticFieldInitSpec(prop, privateNamesMap),
+            buildPrivateStaticFieldInitSpec(
+              prop,
+              privateNamesMap,
+              noUninitializedPrivateFieldAccess,
+            ),
           );
         }
         break;

diff --git a/packages/babel-helper-create-class-features-plugin/src/index.ts b/packages/babel-helper-create-class-features-plugin/src/index.ts
@@ -75,6 +75,8 @@ export function createClassFeaturePlugin({
   const setPublicClassFields = api.assumption("setPublicClassFields");
   const privateFieldsAsSymbols = api.assumption("privateFieldsAsSymbols");
   const privateFieldsAsProperties = api.assumption("privateFieldsAsProperties");
+  const noUninitializedPrivateFieldAccess =
+    api.assumption("noUninitializedPrivateFieldAccess") ?? false;
   const constantSuper = api.assumption("constantSuper");
   const noDocumentAll = api.assumption("noDocumentAll");
 
@@ -256,6 +258,7 @@ export function createClassFeaturePlugin({
           {
             privateFieldsAsProperties:
               privateFieldsAsSymbolsOrProperties ?? loose,
+            noUninitializedPrivateFieldAccess,
             noDocumentAll,
             innerBinding,
           },
@@ -296,6 +299,7 @@ export function createClassFeaturePlugin({
               file,
               setPublicClassFields ?? loose,
               privateFieldsAsSymbolsOrProperties ?? loose,
+              noUninitializedPrivateFieldAccess,
               constantSuper ?? loose,
               innerBinding,
             ));
@@ -317,6 +321,7 @@ export function createClassFeaturePlugin({
             file,
             setPublicClassFields ?? loose,
             privateFieldsAsSymbolsOrProperties ?? loose,
+            noUninitializedPrivateFieldAccess,
             constantSuper ?? loose,
             innerBinding,
           ));

diff --git a/packages/babel-helpers/src/helpers-generated.ts b/packages/babel-helpers/src/helpers-generated.ts
@@ -173,10 +173,10 @@ export default Object.freeze({
     "7.1.5",
     'import toPrimitive from"toPrimitive";export default function toPropertyKey(t){var i=toPrimitive(t,"string");return"symbol"==typeof i?i:String(i)}',
   ),
-  // size: 134, gzip size: 134
+  // size: 144, gzip size: 141
   toSetter: helper(
     "7.22.0",
-    'export default function _toSetter(t,e,n){var r=e.length++;return Object.defineProperty({},"_",{set:function(o){e[r]=o,t.apply(n,e)}})}',
+    'export default function _toSetter(t,e,n){e||(e=[]);var r=e.length++;return Object.defineProperty({},"_",{set:function(o){e[r]=o,t.apply(n,e)}})}',
   ),
   // size: 289, gzip size: 165
   typeof: helper(

diff --git a/packages/babel-helpers/src/helpers/toSetter.ts b/packages/babel-helpers/src/helpers/toSetter.ts
@@ -1,6 +1,7 @@
 /* @minVersion 7.22.0 */
 
 export default function _toSetter(fn: Function, args: any[], thisArg: any) {
+  if (!args) args = [];
   var l = args.length++;
   return Object.defineProperty({}, "_", {
     set: function (v) {

diff --git a/...-class-properties/test/fixtures/assumption-noUninitializedPrivateFieldAccess/options.json b/...-class-properties/test/fixtures/assumption-noUninitializedPrivateFieldAccess/options.json
@@ -0,0 +1,6 @@
+{
+  "plugins": ["transform-class-properties"],
+  "assumptions": {
+    "noUninitializedPrivateFieldAccess": true
+  }
+}
diff --git a/...perties/test/fixtures/assumption-noUninitializedPrivateFieldAccess/static-private/exec.js b/...perties/test/fixtures/assumption-noUninitializedPrivateFieldAccess/static-private/exec.js
@@ -0,0 +1,23 @@
+class A {
+  static #x = 0;
+
+  static dynamicCheck() {
+    expect(this.#x).toBe(0);
+    expect(this.#x = 1).toBe(1);
+    expect(this.#x).toBe(1);
+    [this.#x] = [2];
+    expect(this.#x).toBe(2);
+  }
+
+  static noCheck() {
+    expect(A.#x).toBe(2);
+    expect(A.#x = 3).toBe(3);
+    [A.#x] = [4];
+    expect(A.#x).toBe(4);
+  }
+}
+
+A.dynamicCheck();
+A.noCheck();
+
+
diff --git a/...erties/test/fixtures/assumption-noUninitializedPrivateFieldAccess/static-private/input.js b/...erties/test/fixtures/assumption-noUninitializedPrivateFieldAccess/static-private/input.js
@@ -0,0 +1,15 @@
+class A {
+  static #x = 2;
+
+  static dynamicCheck() {
+    this.#x;
+    this.#x = 2;
+    [this.#x] = [];
+  }
+
+  static noCheck() {
+    A.#x;
+    A.#x = 2;
+    [A.#x] = [];
+  }
+}
diff --git a/...rties/test/fixtures/assumption-noUninitializedPrivateFieldAccess/static-private/output.js b/...rties/test/fixtures/assumption-noUninitializedPrivateFieldAccess/static-private/output.js
@@ -0,0 +1,13 @@
+class A {
+  static dynamicCheck() {
+    babelHelpers.assertClassBrand(this, A, _x);
+    _x = babelHelpers.assertClassBrand(this, A, 2);
+    [babelHelpers.toSetter(babelHelpers.assertClassBrand(this, A, _ => _x = _))._] = [];
+  }
+  static noCheck() {
+    _x;
+    _x = 2;
+    [_x] = [];
+  }
+}
+var _x = 2;