fix: support named evaluation for using declaration (#17317)

JLHwung · web-flow · commit 5addf13d39c6 · 2025-05-16T14:59:32.000-04:00
* fix: support named evaluation for using declaration

* test: mark tdz evaluation test as node 12+

* simplify output
diff --git a/packages/babel-plugin-proposal-explicit-resource-management/src/index.ts b/packages/babel-plugin-proposal-explicit-resource-management/src/index.ts
@@ -7,6 +7,25 @@ const enum USING_KIND {
   AWAIT,
 }
 
+// https://tc39.es/ecma262/#sec-isanonymousfunctiondefinition
+// We don't test anonymous function / arrow function because they must not be disposable
+function isAnonymousFunctionDefinition(
+  node: t.Node,
+): node is t.ClassExpression {
+  return t.isClassExpression(node) && !node.id;
+}
+
+function emitSetFunctionNameCall(
+  state: PluginPass,
+  expression: t.Expression,
+  name: string,
+) {
+  return t.callExpression(state.addHelper("setFunctionName"), [
+    expression,
+    t.stringLiteral(name),
+  ]);
+}
+
 export default declare(api => {
   api.assertVersion(REQUIRED_VERSION("^7.22.0"));
 
@@ -45,10 +64,11 @@ export default declare(api => {
       if (process.env.BABEL_8_BREAKING || state.availableHelper("usingCtx")) {
         let ctx: t.Identifier | null = null;
         let needsAwait = false;
+        const scope = path.scope;
 
         for (const node of path.node.body) {
           if (!isUsingDeclaration(node)) continue;
-          ctx ??= path.scope.generateUidIdentifier("usingCtx");
+          ctx ??= scope.generateUidIdentifier("usingCtx");
           const isAwaitUsing =
             node.kind === "await using" ||
             TOP_LEVEL_USING.get(node) === USING_KIND.AWAIT;
@@ -58,12 +78,18 @@ export default declare(api => {
             node.kind = "const";
           }
           for (const decl of node.declarations) {
+            const currentInit = decl.init;
             decl.init = t.callExpression(
               t.memberExpression(
                 t.cloneNode(ctx),
                 isAwaitUsing ? t.identifier("a") : t.identifier("u"),
               ),
-              [decl.init],
+              [
+                isAnonymousFunctionDefinition(currentInit) &&
+                t.isIdentifier(decl.id)
+                  ? emitSetFunctionNameCall(state, currentInit, decl.id.name)
+                  : currentInit,
+              ],
             );
           }
         }
diff --git a/packages/babel-plugin-proposal-explicit-resource-management/test/fixtures/exec-sync-node-12/named-evaluation-tdz.js b/packages/babel-plugin-proposal-explicit-resource-management/test/fixtures/exec-sync-node-12/named-evaluation-tdz.js
@@ -0,0 +1,3 @@
+expect(() => {
+  using fooTDZ = class { static self = fooTDZ }
+}).toThrow("Cannot access 'fooTDZ' before initialization")
diff --git a/packages/babel-plugin-proposal-explicit-resource-management/test/fixtures/exec-sync-node-12/options.json b/packages/babel-plugin-proposal-explicit-resource-management/test/fixtures/exec-sync-node-12/options.json
@@ -0,0 +1,6 @@
+{
+  "plugins": [
+    "proposal-explicit-resource-management"
+  ],
+  "minNodeVersion": "12.0.0"
+}
diff --git a/packages/babel-plugin-proposal-explicit-resource-management/test/fixtures/exec-sync/named-evaluation.js b/packages/babel-plugin-proposal-explicit-resource-management/test/fixtures/exec-sync/named-evaluation.js
@@ -0,0 +1,8 @@
+let log = [];
+let Symbol$dispose = Symbol.dispose || Symbol.for("Symbol.dispose");
+{
+  using foo = class { static [Symbol$dispose]() { log.push(`${foo.name} is disposed`) } }
+  log.push(foo.name);
+}
+
+expect(log).toEqual(["foo", "foo is disposed"])
diff --git a/packages/babel-plugin-proposal-explicit-resource-management/test/fixtures/transform-sync/named-evaluation/input.js b/packages/babel-plugin-proposal-explicit-resource-management/test/fixtures/transform-sync/named-evaluation/input.js
@@ -0,0 +1,6 @@
+let log = [];
+let Symbol$dispose = Symbol.dispose || Symbol.for("Symbol.dispose");
+{
+  using foo = class { static [Symbol$dispose]() { log.push(`${foo.name} is disposed`) } }
+  log.push(foo.name);
+}
diff --git a/packages/babel-plugin-proposal-explicit-resource-management/test/fixtures/transform-sync/named-evaluation/output.js b/packages/babel-plugin-proposal-explicit-resource-management/test/fixtures/transform-sync/named-evaluation/output.js
@@ -0,0 +1,15 @@
+let log = [];
+let Symbol$dispose = Symbol.dispose || Symbol.for("Symbol.dispose");
+try {
+  var _usingCtx = babelHelpers.usingCtx();
+  const foo = _usingCtx.u(babelHelpers.setFunctionName(class {
+    static [Symbol$dispose]() {
+      log.push(`${foo.name} is disposed`);
+    }
+  }, "foo"));
+  log.push(foo.name);
+} catch (_) {
+  _usingCtx.e = _;
+} finally {
+  _usingCtx.d();
+}

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	`+expect(() => {`
	`2`	`+ using fooTDZ = class { static self = fooTDZ }`
	`3`	`+}).toThrow("Cannot access 'fooTDZ' before initialization")`