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ahejlsbergahejlsberg
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Merge pull request microsoft#21610 from Microsoft/fixSharedTypeParameters
Fix unintended sharing of type parameters
2 parents 120af86 + 8ae5f63 commit d629607

6 files changed

Lines changed: 118 additions & 2 deletions

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‎src/compiler/checker.ts‎

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@@ -8705,7 +8705,7 @@ namespace ts {
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const target = type.objectFlags & ObjectFlags.Instantiated ? type.target : type;
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const symbol = target.symbol;
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const links = getSymbolLinks(symbol);
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let typeParameters = links.typeParameters;
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let typeParameters = links.outerTypeParameters;
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if (!typeParameters) {
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// The first time an anonymous type is instantiated we compute and store a list of the type
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// parameters that are in scope (and therefore potentially referenced). For type literals that
@@ -8716,7 +8716,7 @@ namespace ts {
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typeParameters = symbol.flags & SymbolFlags.TypeLiteral && !target.aliasTypeArguments ?
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filter(outerTypeParameters, tp => isTypeParameterPossiblyReferenced(tp, declaration)) :
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outerTypeParameters;
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links.typeParameters = typeParameters;
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links.outerTypeParameters = typeParameters;
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if (typeParameters.length) {
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links.instantiations = createMap<Type>();
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links.instantiations.set(getTypeListId(typeParameters), target);

‎src/compiler/types.ts‎

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@@ -3312,6 +3312,7 @@ namespace ts {
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type?: Type; // Type of value symbol
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declaredType?: Type; // Type of class, interface, enum, type alias, or type parameter
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typeParameters?: TypeParameter[]; // Type parameters of type alias (undefined if non-generic)
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outerTypeParameters?: TypeParameter[]; // Outer type parameters of anonymous object type
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inferredClassType?: Type; // Type of an inferred ES5 class
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instantiations?: Map<Type>; // Instantiations of generic type alias (undefined if non-generic)
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mapper?: TypeMapper; // Type mapper for instantiation alias

‎tests/baselines/reference/typeAliasFunctionTypeSharedSymbol.js‎

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@@ -0,0 +1,36 @@
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//// [typeAliasFunctionTypeSharedSymbol.ts]
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// Repro from comment in #21496
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function Mixin<TBase extends {new (...args: any[]): {}}>(Base: TBase) {
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return class extends Base {
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};
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}
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type Mixin = ReturnTypeOf<typeof Mixin>
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type ReturnTypeOf<V> = V extends (...args: any[])=>infer R ? R : never;
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type Crashes = number & Mixin;
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//// [typeAliasFunctionTypeSharedSymbol.js]
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// Repro from comment in #21496
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var __extends = (this && this.__extends) || (function () {
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var extendStatics = Object.setPrototypeOf ||
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({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
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function (d, b) { for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; };
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return function (d, b) {
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extendStatics(d, b);
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function __() { this.constructor = d; }
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d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
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};
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})();
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function Mixin(Base) {
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return /** @class */ (function (_super) {
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__extends(class_1, _super);
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function class_1() {
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return _super !== null && _super.apply(this, arguments) || this;
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}
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return class_1;
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}(Base));
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}

‎tests/baselines/reference/typeAliasFunctionTypeSharedSymbol.symbols‎

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@@ -0,0 +1,33 @@
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=== tests/cases/compiler/typeAliasFunctionTypeSharedSymbol.ts ===
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// Repro from comment in #21496
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function Mixin<TBase extends {new (...args: any[]): {}}>(Base: TBase) {
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>Mixin : Symbol(Mixin, Decl(typeAliasFunctionTypeSharedSymbol.ts, 0, 0), Decl(typeAliasFunctionTypeSharedSymbol.ts, 5, 1))
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>TBase : Symbol(TBase, Decl(typeAliasFunctionTypeSharedSymbol.ts, 2, 15))
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>args : Symbol(args, Decl(typeAliasFunctionTypeSharedSymbol.ts, 2, 35))
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>Base : Symbol(Base, Decl(typeAliasFunctionTypeSharedSymbol.ts, 2, 57))
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>TBase : Symbol(TBase, Decl(typeAliasFunctionTypeSharedSymbol.ts, 2, 15))
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return class extends Base {
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>Base : Symbol(Base, Decl(typeAliasFunctionTypeSharedSymbol.ts, 2, 57))
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};
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}
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type Mixin = ReturnTypeOf<typeof Mixin>
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>Mixin : Symbol(Mixin, Decl(typeAliasFunctionTypeSharedSymbol.ts, 0, 0), Decl(typeAliasFunctionTypeSharedSymbol.ts, 5, 1))
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>ReturnTypeOf : Symbol(ReturnTypeOf, Decl(typeAliasFunctionTypeSharedSymbol.ts, 7, 39))
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>Mixin : Symbol(Mixin, Decl(typeAliasFunctionTypeSharedSymbol.ts, 0, 0), Decl(typeAliasFunctionTypeSharedSymbol.ts, 5, 1))
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type ReturnTypeOf<V> = V extends (...args: any[])=>infer R ? R : never;
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>ReturnTypeOf : Symbol(ReturnTypeOf, Decl(typeAliasFunctionTypeSharedSymbol.ts, 7, 39))
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>V : Symbol(V, Decl(typeAliasFunctionTypeSharedSymbol.ts, 9, 18))
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>V : Symbol(V, Decl(typeAliasFunctionTypeSharedSymbol.ts, 9, 18))
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>args : Symbol(args, Decl(typeAliasFunctionTypeSharedSymbol.ts, 9, 34))
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>R : Symbol(R, Decl(typeAliasFunctionTypeSharedSymbol.ts, 9, 56))
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>R : Symbol(R, Decl(typeAliasFunctionTypeSharedSymbol.ts, 9, 56))
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type Crashes = number & Mixin;
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>Crashes : Symbol(Crashes, Decl(typeAliasFunctionTypeSharedSymbol.ts, 9, 71))
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>Mixin : Symbol(Mixin, Decl(typeAliasFunctionTypeSharedSymbol.ts, 0, 0), Decl(typeAliasFunctionTypeSharedSymbol.ts, 5, 1))
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‎tests/baselines/reference/typeAliasFunctionTypeSharedSymbol.types‎

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@@ -0,0 +1,34 @@
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=== tests/cases/compiler/typeAliasFunctionTypeSharedSymbol.ts ===
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// Repro from comment in #21496
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function Mixin<TBase extends {new (...args: any[]): {}}>(Base: TBase) {
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>Mixin : <TBase extends new (...args: any[]) => {}>(Base: TBase) => { new (...args: any[]): (Anonymous class); prototype: Mixin<any>.(Anonymous class); } & TBase
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>TBase : TBase
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>args : any[]
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>Base : TBase
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>TBase : TBase
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return class extends Base {
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>class extends Base { } : { new (...args: any[]): (Anonymous class); prototype: Mixin<any>.(Anonymous class); } & TBase
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>Base : {}
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};
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}
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type Mixin = ReturnTypeOf<typeof Mixin>
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>Mixin : { new (...args: any[]): Mixin<new (...args: any[]) => {}>.(Anonymous class); prototype: Mixin<any>.(Anonymous class); } & (new (...args: any[]) => {})
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>ReturnTypeOf : ReturnTypeOf<V>
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>Mixin : <TBase extends new (...args: any[]) => {}>(Base: TBase) => { new (...args: any[]): (Anonymous class); prototype: Mixin<any>.(Anonymous class); } & TBase
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type ReturnTypeOf<V> = V extends (...args: any[])=>infer R ? R : never;
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>ReturnTypeOf : ReturnTypeOf<V>
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>V : V
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>V : V
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>args : any[]
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>R : R
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>R : R
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type Crashes = number & Mixin;
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>Crashes : Crashes
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>Mixin : { new (...args: any[]): Mixin<new (...args: any[]) => {}>.(Anonymous class); prototype: Mixin<any>.(Anonymous class); } & (new (...args: any[]) => {})
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‎tests/cases/compiler/typeAliasFunctionTypeSharedSymbol.ts‎

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@@ -0,0 +1,12 @@
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// Repro from comment in #21496
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function Mixin<TBase extends {new (...args: any[]): {}}>(Base: TBase) {
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return class extends Base {
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};
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}
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type Mixin = ReturnTypeOf<typeof Mixin>
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type ReturnTypeOf<V> = V extends (...args: any[])=>infer R ? R : never;
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type Crashes = number & Mixin;

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