Fix downlevel async super in default parameters (#4104)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: jakebailey <5341706+jakebailey@users.noreply.github.com>

Author: Copilot

internal/transformers/estransforms/async.go

@@ -722,12 +722,25 @@ func (tx *asyncTransformer) transformAsyncFunctionParameterList(node *ast.Node)
 }
 
 func (tx *asyncTransformer) transformAsyncFunctionBody(node *ast.Node, outerParameters *ast.NodeList) *ast.Node {
+	isArrow := node.Kind == ast.KindArrowFunction
+	savedCapturedSuperProperties := tx.capturedSuperProperties
+	savedHasSuperElementAccess := tx.hasSuperElementAccess
+	savedHasSuperPropertyAssignment := tx.hasSuperPropertyAssignment
+	savedSuperBinding := tx.superBinding
+	savedSuperIndexBinding := tx.superIndexBinding
+	if !isArrow {
+		tx.capturedSuperProperties = &collections.OrderedSet[string]{}
+		tx.hasSuperElementAccess = false
+		tx.hasSuperPropertyAssignment = false
+		tx.superBinding = tx.Factory().NewUniqueNameEx("_super", printer.AutoGenerateOptions{Flags: printer.GeneratedIdentifierFlagsOptimistic | printer.GeneratedIdentifierFlagsFileLevel})
+		tx.superIndexBinding = tx.Factory().NewUniqueNameEx("_superIndex", printer.AutoGenerateOptions{Flags: printer.GeneratedIdentifierFlagsOptimistic | printer.GeneratedIdentifierFlagsFileLevel})
+	}
+
 	innerParameters := (*ast.NodeList)(nil)
 	if !isSimpleParameterList(node.Parameters()) {
 		innerParameters = tx.EmitContext().VisitParameters(node.ParameterList(), tx.Visitor())
 	}
 
-	isArrow := node.Kind == ast.KindArrowFunction
 	savedLexicalArguments := tx.lexicalArguments
 	captureLexicalArguments := tx.lexicalArguments.binding == nil
 	if captureLexicalArguments {
@@ -773,19 +786,6 @@ func (tx *asyncTransformer) transformAsyncFunctionBody(node *ast.Node, outerPara
 		tx.recordDeclarationName(parameter, tx.enclosingFunctionParameterNames)
 	}
 
-	savedCapturedSuperProperties := tx.capturedSuperProperties
-	savedHasSuperElementAccess := tx.hasSuperElementAccess
-	savedHasSuperPropertyAssignment := tx.hasSuperPropertyAssignment
-	savedSuperBinding := tx.superBinding
-	savedSuperIndexBinding := tx.superIndexBinding
-	if !isArrow {
-		tx.capturedSuperProperties = &collections.OrderedSet[string]{}
-		tx.hasSuperElementAccess = false
-		tx.hasSuperPropertyAssignment = false
-		tx.superBinding = tx.Factory().NewUniqueNameEx("_super", printer.AutoGenerateOptions{Flags: printer.GeneratedIdentifierFlagsOptimistic | printer.GeneratedIdentifierFlagsFileLevel})
-		tx.superIndexBinding = tx.Factory().NewUniqueNameEx("_superIndex", printer.AutoGenerateOptions{Flags: printer.GeneratedIdentifierFlagsOptimistic | printer.GeneratedIdentifierFlagsFileLevel})
-	}
-
 	hasLexicalThis := tx.inHasLexicalThisContext()
 
 	asyncBody := tx.transformAsyncFunctionBodyWorker(node.Body())
@@ -799,6 +799,7 @@ func (tx *asyncTransformer) transformAsyncFunctionBody(node *ast.Node, outerPara
 	emitSuperHelpers := tx.capturedSuperProperties != nil &&
 		(tx.capturedSuperProperties.Size() > 0 || tx.hasSuperElementAccess)
 	if emitSuperHelpers {
+		innerParameters = tx.superAccessVisitor.VisitNodes(innerParameters)
 		asyncBody = tx.substituteSuperAccessesInBody(asyncBody)
 	}
 

testdata/baselines/reference/compiler/asyncSuperDefaultParameters.js

@@ -0,0 +1,54 @@
+//// [tests/cases/compiler/asyncSuperDefaultParameters.ts] ////
+
+//// [asyncSuperDefaultParameters.ts]
+class B {
+    m() {
+        return 1;
+    }
+}
+
+class C extends B {
+    f() {
+        const g = async (b = super.m()) => b;
+        return g();
+    }
+
+    async h(b = super.m()) {
+        return b;
+    }
+}
+
+
+//// [asyncSuperDefaultParameters.js]
+"use strict";
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+};
+class B {
+    m() {
+        return 1;
+    }
+}
+class C extends B {
+    f() {
+        const _super = Object.create(null, {
+            m: { get: () => super.m }
+        });
+        const g = (...args_1) => __awaiter(this, [...args_1], void 0, function* (b = _super.m.call(this)) { return b; });
+        return g();
+    }
+    h() {
+        const _super = Object.create(null, {
+            m: { get: () => super.m }
+        });
+        return __awaiter(this, arguments, void 0, function* (b = _super.m.call(this)) {
+            return b;
+        });
+    }
+}

testdata/tests/cases/compiler/asyncSuperDefaultParameters.ts

@@ -0,0 +1,19 @@
+// @target: es2015
+// @noTypesAndSymbols: true
+
+class B {
+    m() {
+        return 1;
+    }
+}
+
+class C extends B {
+    f() {
+        const g = async (b = super.m()) => b;
+        return g();
+    }
+
+    async h(b = super.m()) {
+        return b;
+    }
+}