Preserve class bindings in computed member names

tsc/internal/transformers/tstransforms/legacydecorators.go

@@ -1,6 +1,8 @@
 package tstransforms
 
 import (
+	"slices"
+
 	"github.com/microsoft/TypeScript/tsc/internal/ast"
 	"github.com/microsoft/TypeScript/tsc/internal/binder"
 	"github.com/microsoft/TypeScript/tsc/internal/collections"
@@ -20,6 +22,8 @@ type LegacyDecoratorsTransformer struct {
 	 */
 	classAliases     map[*ast.Node]*ast.Node
 	enclosingClasses []*ast.ClassDeclaration
+	// Class aliases that should not be substituted while visiting a direct computed member name.
+	excludedClassAliases []*ast.Node
 }
 
 func NewLegacyDecoratorsTransformer(opt *transformers.TransformOptions) *transformers.Transformer {
@@ -60,10 +64,12 @@ func (tx *LegacyDecoratorsTransformer) visit(node *ast.Node) *ast.Node {
 	case ast.KindSourceFile:
 		tx.classAliases = make(map[*ast.Node]*ast.Node)
 		tx.enclosingClasses = nil
+		tx.excludedClassAliases = nil
 		result := tx.Visitor().VisitEachChild(node)
 		tx.EmitContext().AddEmitHelper(result, tx.EmitContext().ReadEmitHelpers()...)
 		tx.classAliases = nil
 		tx.enclosingClasses = nil
+		tx.excludedClassAliases = nil
 		return result
 	default:
 		return tx.Visitor().VisitEachChild(node)
@@ -73,7 +79,7 @@ func (tx *LegacyDecoratorsTransformer) visit(node *ast.Node) *ast.Node {
 func (tx *LegacyDecoratorsTransformer) visitIdentifier(node *ast.Identifier) *ast.Node {
 	// takes the place of `substituteIdentifier` in the strada transform
 	for _, d := range tx.enclosingClasses {
-		if _, ok := tx.classAliases[d.AsNode()]; ok && tx.referenceResolver.GetReferencedValueDeclaration(tx.EmitContext().MostOriginal(node.AsNode())) == tx.EmitContext().MostOriginal(d.AsNode()) {
+		if _, ok := tx.classAliases[d.AsNode()]; ok && !slices.Contains(tx.excludedClassAliases, d.AsNode()) && tx.referenceResolver.GetReferencedValueDeclaration(tx.EmitContext().MostOriginal(node.AsNode())) == tx.EmitContext().MostOriginal(d.AsNode()) {
 			return tx.classAliases[d.AsNode()]
 		}
 	}
@@ -152,6 +158,20 @@ func (tx *LegacyDecoratorsTransformer) visitParamerDeclaration(node *ast.Paramet
 // with decorators, a temporary value is stored for later use.
 func (tx *LegacyDecoratorsTransformer) visitPropertyNameOfClassElement(member *ast.Node) *ast.Node {
 	name := member.Name()
+	if ast.IsComputedPropertyName(name) {
+		// A direct computed name is evaluated before its class alias is assigned. Exclude only
+		// that class so references to aliases of enclosing classes are still substituted.
+		for i := len(tx.enclosingClasses) - 1; i >= 0; i-- {
+			class := tx.enclosingClasses[i]
+			if slices.Contains(class.Members.Nodes, member) {
+				tx.excludedClassAliases = append(tx.excludedClassAliases, class.AsNode())
+				defer func() {
+					tx.excludedClassAliases = tx.excludedClassAliases[:len(tx.excludedClassAliases)-1]
+				}()
+				break
+			}
+		}
+	}
 	if ast.IsComputedPropertyName(name) && ast.HasDecorators(member) {
 		expression := tx.Visitor().VisitNode(name.AsComputedPropertyName().Expression)
 		innerExpression := ast.SkipPartiallyEmittedExpressions(expression)
@@ -511,8 +531,18 @@ func (tx *LegacyDecoratorsTransformer) transformClassDeclarationWithClassDecorat
 
 func (tx *LegacyDecoratorsTransformer) hasInternalStaticReference(node *ast.ClassDeclaration) bool {
 	classNode := tx.EmitContext().MostOriginal(node.AsNode())
+	computedNames := make(map[*ast.Node]struct{})
+	for _, member := range node.Members.Nodes {
+		if name := member.Name(); name != nil && ast.IsComputedPropertyName(name) {
+			// Direct computed names are evaluated before the class alias can be assigned.
+			computedNames[name] = struct{}{}
+		}
+	}
 	var isOrContainsStaticSelfReference func(n *ast.Node) bool
 	isOrContainsStaticSelfReference = func(n *ast.Node) bool {
+		if _, ok := computedNames[n]; ok {
+			return false
+		}
 		if ast.IsIdentifier(n) && tx.referenceResolver.GetReferencedValueDeclaration(tx.EmitContext().MostOriginal(n)) == classNode {
 			return true
 		}

tsc/testdata/baselines/reference/compiler/legacyDecoratorClassAliasComputedNames(target=es2020).errors.txt

@@ -0,0 +1,47 @@
+legacyDecoratorClassAliasComputedNames.ts(6,6): error TS2449: Class 'C' used before its declaration.
+legacyDecoratorClassAliasComputedNames.ts(7,10): error TS2449: Class 'C' used before its declaration.
+legacyDecoratorClassAliasComputedNames.ts(8,10): error TS2449: Class 'C' used before its declaration.
+legacyDecoratorClassAliasComputedNames.ts(14,13): error TS2449: Class 'D' used before its declaration.
+
+
+==== legacyDecoratorClassAliasComputedNames.ts (4 errors) ====
+    declare function dec(...args: any[]): any;
+
+    @dec
+    class C {
+        constructor() {}
+        [C.name]() {}
+         ~
+!!! error TS2449: Class 'C' used before its declaration.
+!!! related TS2728 legacyDecoratorClassAliasComputedNames.ts:4:7: 'C' is declared here.
+        get [C.name]() { return 1; }
+             ~
+!!! error TS2449: Class 'C' used before its declaration.
+!!! related TS2728 legacyDecoratorClassAliasComputedNames.ts:4:7: 'C' is declared here.
+        set [C.name](value: number) {}
+             ~
+!!! error TS2449: Class 'C' used before its declaration.
+!!! related TS2728 legacyDecoratorClassAliasComputedNames.ts:4:7: 'C' is declared here.
+    }
+
+    @dec
+    class D {
+        @dec
+        static [D.name] = 1;
+                ~
+!!! error TS2449: Class 'D' used before its declaration.
+!!! related TS2728 legacyDecoratorClassAliasComputedNames.ts:12:7: 'D' is declared here.
+        static getSelf() {
+            return D;
+        }
+    }
+
+    @dec
+    class Outer {
+        method() {
+            return class {
+                [Outer.name]() {}
+            };
+        }
+    }
+

tsc/testdata/baselines/reference/compiler/legacyDecoratorClassAliasComputedNames(target=es2020).js

@@ -0,0 +1,73 @@
+//// [tests/cases/compiler/legacyDecoratorClassAliasComputedNames.ts] ////
+
+//// [legacyDecoratorClassAliasComputedNames.ts]
+declare function dec(...args: any[]): any;
+
+@dec
+class C {
+    constructor() {}
+    [C.name]() {}
+    get [C.name]() { return 1; }
+    set [C.name](value: number) {}
+}
+
+@dec
+class D {
+    @dec
+    static [D.name] = 1;
+    static getSelf() {
+        return D;
+    }
+}
+
+@dec
+class Outer {
+    method() {
+        return class {
+            [Outer.name]() {}
+        };
+    }
+}
+
+
+//// [legacyDecoratorClassAliasComputedNames.js]
+"use strict";
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var D_1, _a, Outer_1;
+let C = class C {
+    constructor() { }
+    [C.name]() { }
+    get [C.name]() { return 1; }
+    set [C.name](value) { }
+};
+C = __decorate([
+    dec
+], C);
+let D = D_1 = class D {
+    static getSelf() {
+        return D_1;
+    }
+};
+_a = D.name;
+D[_a] = 1;
+__decorate([
+    dec
+], D, _a, void 0);
+D = D_1 = __decorate([
+    dec
+], D);
+let Outer = Outer_1 = class Outer {
+    method() {
+        return class {
+            [Outer_1.name]() { }
+        };
+    }
+};
+Outer = Outer_1 = __decorate([
+    dec
+], Outer);

tsc/testdata/baselines/reference/compiler/legacyDecoratorClassAliasComputedNames(target=es2020).symbols

@@ -0,0 +1,77 @@
+//// [tests/cases/compiler/legacyDecoratorClassAliasComputedNames.ts] ////
+
+=== legacyDecoratorClassAliasComputedNames.ts ===
+declare function dec(...args: any[]): any;
+>dec : Symbol(dec, Decl(legacyDecoratorClassAliasComputedNames.ts, 0, 0))
+>args : Symbol(args, Decl(legacyDecoratorClassAliasComputedNames.ts, 0, 21))
+
+@dec
+>dec : Symbol(dec, Decl(legacyDecoratorClassAliasComputedNames.ts, 0, 0))
+
+class C {
+>C : Symbol(C, Decl(legacyDecoratorClassAliasComputedNames.ts, 0, 42))
+
+    constructor() {}
+    [C.name]() {}
+>[C.name] : Symbol(C[C.name], Decl(legacyDecoratorClassAliasComputedNames.ts, 4, 20))
+>C.name : Symbol(Function.name, Decl(lib.es2015.core.d.ts, --, --))
+>C : Symbol(C, Decl(legacyDecoratorClassAliasComputedNames.ts, 0, 42))
+>name : Symbol(Function.name, Decl(lib.es2015.core.d.ts, --, --))
+
+    get [C.name]() { return 1; }
+>[C.name] : Symbol(C[C.name], Decl(legacyDecoratorClassAliasComputedNames.ts, 5, 17))
+>C.name : Symbol(Function.name, Decl(lib.es2015.core.d.ts, --, --))
+>C : Symbol(C, Decl(legacyDecoratorClassAliasComputedNames.ts, 0, 42))
+>name : Symbol(Function.name, Decl(lib.es2015.core.d.ts, --, --))
+
+    set [C.name](value: number) {}
+>[C.name] : Symbol(C[C.name], Decl(legacyDecoratorClassAliasComputedNames.ts, 6, 32))
+>C.name : Symbol(Function.name, Decl(lib.es2015.core.d.ts, --, --))
+>C : Symbol(C, Decl(legacyDecoratorClassAliasComputedNames.ts, 0, 42))
+>name : Symbol(Function.name, Decl(lib.es2015.core.d.ts, --, --))
+>value : Symbol(value, Decl(legacyDecoratorClassAliasComputedNames.ts, 7, 17))
+}
+
+@dec
+>dec : Symbol(dec, Decl(legacyDecoratorClassAliasComputedNames.ts, 0, 0))
+
+class D {
+>D : Symbol(D, Decl(legacyDecoratorClassAliasComputedNames.ts, 8, 1))
+
+    @dec
+>dec : Symbol(dec, Decl(legacyDecoratorClassAliasComputedNames.ts, 0, 0))
+
+    static [D.name] = 1;
+>[D.name] : Symbol(D[D.name], Decl(legacyDecoratorClassAliasComputedNames.ts, 11, 9))
+>D.name : Symbol(Function.name, Decl(lib.es2015.core.d.ts, --, --))
+>D : Symbol(D, Decl(legacyDecoratorClassAliasComputedNames.ts, 8, 1))
+>name : Symbol(Function.name, Decl(lib.es2015.core.d.ts, --, --))
+
+    static getSelf() {
+>getSelf : Symbol(D.getSelf, Decl(legacyDecoratorClassAliasComputedNames.ts, 13, 24))
+
+        return D;
+>D : Symbol(D, Decl(legacyDecoratorClassAliasComputedNames.ts, 8, 1))
+    }
+}
+
+@dec
+>dec : Symbol(dec, Decl(legacyDecoratorClassAliasComputedNames.ts, 0, 0))
+
+class Outer {
+>Outer : Symbol(Outer, Decl(legacyDecoratorClassAliasComputedNames.ts, 17, 1))
+
+    method() {
+>method : Symbol(Outer.method, Decl(legacyDecoratorClassAliasComputedNames.ts, 20, 13))
+
+        return class {
+            [Outer.name]() {}
+>[Outer.name] : Symbol((Anonymous class)[Outer.name], Decl(legacyDecoratorClassAliasComputedNames.ts, 22, 22))
+>Outer.name : Symbol(Function.name, Decl(lib.es2015.core.d.ts, --, --))
+>Outer : Symbol(Outer, Decl(legacyDecoratorClassAliasComputedNames.ts, 17, 1))
+>name : Symbol(Function.name, Decl(lib.es2015.core.d.ts, --, --))
+
+        };
+    }
+}
+

tsc/testdata/baselines/reference/compiler/legacyDecoratorClassAliasComputedNames(target=es2020).types

@@ -0,0 +1,81 @@
+//// [tests/cases/compiler/legacyDecoratorClassAliasComputedNames.ts] ////
+
+=== legacyDecoratorClassAliasComputedNames.ts ===
+declare function dec(...args: any[]): any;
+>dec : (...args: any[]) => any
+>args : any[]
+
+@dec
+>dec : (...args: any[]) => any
+
+class C {
+>C : C
+
+    constructor() {}
+    [C.name]() {}
+>[C.name] : () => void
+>C.name : string
+>C : typeof C
+>name : string
+
+    get [C.name]() { return 1; }
+>[C.name] : number
+>C.name : string
+>C : typeof C
+>name : string
+>1 : 1
+
+    set [C.name](value: number) {}
+>[C.name] : number
+>C.name : string
+>C : typeof C
+>name : string
+>value : number
+}
+
+@dec
+>dec : (...args: any[]) => any
+
+class D {
+>D : D
+
+    @dec
+>dec : (...args: any[]) => any
+
+    static [D.name] = 1;
+>[D.name] : number
+>D.name : string
+>D : typeof D
+>name : string
+>1 : 1
+
+    static getSelf() {
+>getSelf : () => typeof D
+
+        return D;
+>D : typeof D
+    }
+}
+
+@dec
+>dec : (...args: any[]) => any
+
+class Outer {
+>Outer : Outer
+
+    method() {
+>method : () => typeof (Anonymous class)
+
+        return class {
+>class {            [Outer.name]() {}        } : typeof (Anonymous class)
+
+            [Outer.name]() {}
+>[Outer.name] : () => void
+>Outer.name : string
+>Outer : typeof Outer
+>name : string
+
+        };
+    }
+}
+