Write non-missing undefined on mapped type results into output (#59208)

microsoft · Jul 10, 2024 · ed17a89 · ed17a89
1 parent 2fd707d
commit ed17a89
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Showing 13 changed files with 370 additions and 26 deletions.
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -6113,11 +6113,12 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         ) {
             const originalType = type;
             if (addUndefined) {
-                type = getOptionalType(type);
+                type = getOptionalType(type, !isParameter(host));
             }
             const clone = tryReuseExistingNonParameterTypeNode(context, typeNode, type, host);
             if (clone) {
-                if (addUndefined && !someType(getTypeFromTypeNode(context, typeNode), t => !!(t.flags & TypeFlags.Undefined))) {
+                // explicitly add `| undefined` if it's missing from the input type nodes and the type contains `undefined` (and not the missing type)
+                if (addUndefined && containsNonMissingUndefinedType(type) && !someType(getTypeFromTypeNode(context, typeNode), t => !!(t.flags & TypeFlags.Undefined))) {
                     return factory.createUnionTypeNode([clone, factory.createKeywordTypeNode(SyntaxKind.UndefinedKeyword)]);
                 }
                 return clone;
@@ -8252,7 +8253,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
          * @param symbol - The symbol is used both to find an existing annotation if declaration is not provided, and to determine if `unique symbol` should be printed
          */
         function serializeTypeForDeclaration(context: NodeBuilderContext, declaration: Declaration | undefined, type: Type, symbol: Symbol) {
-            const addUndefined = declaration && (isParameter(declaration) || isJSDocParameterTag(declaration)) && requiresAddingImplicitUndefined(declaration);
+            const addUndefinedForParameter = declaration && (isParameter(declaration) || isJSDocParameterTag(declaration)) && requiresAddingImplicitUndefined(declaration);
             const enclosingDeclaration = context.enclosingDeclaration;
             const oldFlags = context.flags;
             if (declaration && hasInferredType(declaration) && !(context.flags & NodeBuilderFlags.NoSyntacticPrinter)) {
@@ -8266,6 +8267,8 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 if (declWithExistingAnnotation && !isFunctionLikeDeclaration(declWithExistingAnnotation) && !isGetAccessorDeclaration(declWithExistingAnnotation)) {
                     // try to reuse the existing annotation
                     const existing = getNonlocalEffectiveTypeAnnotationNode(declWithExistingAnnotation)!;
+                    // explicitly add `| undefined` to optional mapped properties whose type contains `undefined` (and not `missing`)
+                    const addUndefined = addUndefinedForParameter || !!(symbol.flags & SymbolFlags.Property && symbol.flags & SymbolFlags.Optional && isOptionalDeclaration(declWithExistingAnnotation) && (symbol as MappedSymbol).links?.mappedType && containsNonMissingUndefinedType(type));
                     const result = !isTypePredicateNode(existing) && tryReuseExistingTypeNode(context, existing, type, declWithExistingAnnotation, addUndefined);
                     if (result) {
                         context.flags = oldFlags;
@@ -8283,7 +8286,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             const decl = declaration ?? symbol.valueDeclaration ?? symbol.declarations?.[0];
             const expr = decl && isDeclarationWithPossibleInnerTypeNodeReuse(decl) ? getPossibleTypeNodeReuseExpression(decl) : undefined;
 
-            const result = expressionOrTypeToTypeNode(context, expr, type, addUndefined);
+            const result = expressionOrTypeToTypeNode(context, expr, type, addUndefinedForParameter);
             context.flags = oldFlags;
             return result;
         }
@@ -21425,6 +21428,11 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         return !!((type.flags & TypeFlags.Union ? (type as UnionType).types[0] : type).flags & TypeFlags.Undefined);
     }
 
+    function containsNonMissingUndefinedType(type: Type) {
+        const candidate = type.flags & TypeFlags.Union ? (type as UnionType).types[0] : type;
+        return !!(candidate.flags & TypeFlags.Undefined) && candidate !== missingType;
+    }
+
     function isStringIndexSignatureOnlyType(type: Type): boolean {
         return type.flags & TypeFlags.Object && !isGenericMappedType(type) && getPropertiesOfType(type).length === 0 && getIndexInfosOfType(type).length === 1 && !!getIndexInfoOfType(type, stringType) ||
             type.flags & TypeFlags.UnionOrIntersection && every((type as UnionOrIntersectionType).types, isStringIndexSignatureOnlyType) ||

diff --git a/...clarationEmitExactOptionalPropertyTypesNodeNotReused(exactoptionalpropertytypes=false).js b/...clarationEmitExactOptionalPropertyTypesNodeNotReused(exactoptionalpropertytypes=false).js
@@ -0,0 +1,39 @@
+//// [tests/cases/compiler/declarationEmitExactOptionalPropertyTypesNodeNotReused.ts] ////
+
+//// [declarationEmitExactOptionalPropertyTypesNodeNotReused.ts]
+type InexactOptionals<A> = {
+    [K in keyof A as undefined extends A[K] ? K : never]?: undefined extends A[K]
+    ? A[K] | undefined
+    : A[K];
+} & {
+    [K in keyof A as undefined extends A[K] ? never : K]: A[K];
+};
+
+type In = {
+    foo?: string;
+    bar: number;
+    baz: undefined;
+}
+
+type Out = InexactOptionals<In>
+
+const foo = <A = {}>() => (x: Out & A) => null
+
+export const baddts = foo()
+
+
+//// [declarationEmitExactOptionalPropertyTypesNodeNotReused.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.baddts = void 0;
+var foo = function () { return function (x) { return null; }; };
+exports.baddts = foo();
+
+
+//// [declarationEmitExactOptionalPropertyTypesNodeNotReused.d.ts]
+export declare const baddts: (x: {
+    foo?: string | undefined;
+    baz?: undefined;
+} & {
+    bar: number;
+}) => null;
diff --git a/...tionEmitExactOptionalPropertyTypesNodeNotReused(exactoptionalpropertytypes=false).symbols b/...tionEmitExactOptionalPropertyTypesNodeNotReused(exactoptionalpropertytypes=false).symbols
@@ -0,0 +1,65 @@
+//// [tests/cases/compiler/declarationEmitExactOptionalPropertyTypesNodeNotReused.ts] ////
+
+=== declarationEmitExactOptionalPropertyTypesNodeNotReused.ts ===
+type InexactOptionals<A> = {
+>InexactOptionals : Symbol(InexactOptionals, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 0))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+
+    [K in keyof A as undefined extends A[K] ? K : never]?: undefined extends A[K]
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 1, 5))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 1, 5))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 1, 5))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 1, 5))
+
+    ? A[K] | undefined
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 1, 5))
+
+    : A[K];
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 1, 5))
+
+} & {
+    [K in keyof A as undefined extends A[K] ? never : K]: A[K];
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 5, 5))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 5, 5))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 5, 5))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 5, 5))
+
+};
+
+type In = {
+>In : Symbol(In, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 6, 2))
+
+    foo?: string;
+>foo : Symbol(foo, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 8, 11))
+
+    bar: number;
+>bar : Symbol(bar, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 9, 17))
+
+    baz: undefined;
+>baz : Symbol(baz, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 10, 16))
+}
+
+type Out = InexactOptionals<In>
+>Out : Symbol(Out, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 12, 1))
+>InexactOptionals : Symbol(InexactOptionals, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 0))
+>In : Symbol(In, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 6, 2))
+
+const foo = <A = {}>() => (x: Out & A) => null
+>foo : Symbol(foo, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 16, 5))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 16, 13))
+>x : Symbol(x, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 16, 27))
+>Out : Symbol(Out, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 12, 1))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 16, 13))
+
+export const baddts = foo()
+>baddts : Symbol(baddts, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 18, 12))
+>foo : Symbol(foo, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 16, 5))
+
diff --git a/...rationEmitExactOptionalPropertyTypesNodeNotReused(exactoptionalpropertytypes=false).types b/...rationEmitExactOptionalPropertyTypesNodeNotReused(exactoptionalpropertytypes=false).types
@@ -0,0 +1,53 @@
+//// [tests/cases/compiler/declarationEmitExactOptionalPropertyTypesNodeNotReused.ts] ////
+
+=== declarationEmitExactOptionalPropertyTypesNodeNotReused.ts ===
+type InexactOptionals<A> = {
+>InexactOptionals : InexactOptionals<A>
+>                 : ^^^^^^^^^^^^^^^^^^^
+
+    [K in keyof A as undefined extends A[K] ? K : never]?: undefined extends A[K]
+    ? A[K] | undefined
+    : A[K];
+} & {
+    [K in keyof A as undefined extends A[K] ? never : K]: A[K];
+};
+
+type In = {
+>In : In
+>   : ^^
+
+    foo?: string;
+>foo : string | undefined
+>    : ^^^^^^^^^^^^^^^^^^
+
+    bar: number;
+>bar : number
+>    : ^^^^^^
+
+    baz: undefined;
+>baz : undefined
+>    : ^^^^^^^^^
+}
+
+type Out = InexactOptionals<In>
+>Out : Out
+>    : ^^^
+
+const foo = <A = {}>() => (x: Out & A) => null
+>foo : <A = {}>() => (x: Out & A) => null
+>    : ^ ^^^^^^^^^^^^^ ^^       ^^^^^^^^^
+><A = {}>() => (x: Out & A) => null : <A = {}>() => (x: Out & A) => null
+>                                   : ^ ^^^^^^^^^^^^^ ^^       ^^^^^^^^^
+>(x: Out & A) => null : (x: Out & A) => null
+>                     : ^ ^^       ^^^^^^^^^
+>x : { foo?: string | undefined; baz?: undefined; } & { bar: number; } & A
+>  : ^^^^^^^^      ^^^^^^^^^^^^^^^^^^^^         ^^^^^^^^^^^^^      ^^^^^^^
+
+export const baddts = foo()
+>baddts : (x: { foo?: string | undefined; baz?: undefined; } & { bar: number; }) => null
+>       : ^ ^^^^^^^^^^      ^^^^^^^^^^^^^^^^^^^^         ^^^^^^^^^^^^^      ^^^^^^^^^^^^
+>foo() : (x: { foo?: string | undefined; baz?: undefined; } & { bar: number; }) => null
+>      : ^ ^^^^^^^^^^      ^^^^^^^^^^^^^^^^^^^^         ^^^^^^^^^^^^^      ^^^^^^^^^^^^
+>foo : <A = {}>() => (x: Out & A) => null
+>    : ^ ^^^^^^^^^^^^^ ^^       ^^^^^^^^^
+
diff --git a/...eclarationEmitExactOptionalPropertyTypesNodeNotReused(exactoptionalpropertytypes=true).js b/...eclarationEmitExactOptionalPropertyTypesNodeNotReused(exactoptionalpropertytypes=true).js
@@ -0,0 +1,39 @@
+//// [tests/cases/compiler/declarationEmitExactOptionalPropertyTypesNodeNotReused.ts] ////
+
+//// [declarationEmitExactOptionalPropertyTypesNodeNotReused.ts]
+type InexactOptionals<A> = {
+    [K in keyof A as undefined extends A[K] ? K : never]?: undefined extends A[K]
+    ? A[K] | undefined
+    : A[K];
+} & {
+    [K in keyof A as undefined extends A[K] ? never : K]: A[K];
+};
+
+type In = {
+    foo?: string;
+    bar: number;
+    baz: undefined;
+}
+
+type Out = InexactOptionals<In>
+
+const foo = <A = {}>() => (x: Out & A) => null
+
+export const baddts = foo()
+
+
+//// [declarationEmitExactOptionalPropertyTypesNodeNotReused.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.baddts = void 0;
+var foo = function () { return function (x) { return null; }; };
+exports.baddts = foo();
+
+
+//// [declarationEmitExactOptionalPropertyTypesNodeNotReused.d.ts]
+export declare const baddts: (x: {
+    foo?: string | undefined;
+    baz?: undefined;
+} & {
+    bar: number;
+}) => null;
diff --git a/...ationEmitExactOptionalPropertyTypesNodeNotReused(exactoptionalpropertytypes=true).symbols b/...ationEmitExactOptionalPropertyTypesNodeNotReused(exactoptionalpropertytypes=true).symbols
@@ -0,0 +1,65 @@
+//// [tests/cases/compiler/declarationEmitExactOptionalPropertyTypesNodeNotReused.ts] ////
+
+=== declarationEmitExactOptionalPropertyTypesNodeNotReused.ts ===
+type InexactOptionals<A> = {
+>InexactOptionals : Symbol(InexactOptionals, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 0))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+
+    [K in keyof A as undefined extends A[K] ? K : never]?: undefined extends A[K]
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 1, 5))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 1, 5))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 1, 5))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 1, 5))
+
+    ? A[K] | undefined
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 1, 5))
+
+    : A[K];
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 1, 5))
+
+} & {
+    [K in keyof A as undefined extends A[K] ? never : K]: A[K];
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 5, 5))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 5, 5))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 5, 5))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 22))
+>K : Symbol(K, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 5, 5))
+
+};
+
+type In = {
+>In : Symbol(In, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 6, 2))
+
+    foo?: string;
+>foo : Symbol(foo, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 8, 11))
+
+    bar: number;
+>bar : Symbol(bar, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 9, 17))
+
+    baz: undefined;
+>baz : Symbol(baz, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 10, 16))
+}
+
+type Out = InexactOptionals<In>
+>Out : Symbol(Out, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 12, 1))
+>InexactOptionals : Symbol(InexactOptionals, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 0, 0))
+>In : Symbol(In, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 6, 2))
+
+const foo = <A = {}>() => (x: Out & A) => null
+>foo : Symbol(foo, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 16, 5))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 16, 13))
+>x : Symbol(x, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 16, 27))
+>Out : Symbol(Out, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 12, 1))
+>A : Symbol(A, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 16, 13))
+
+export const baddts = foo()
+>baddts : Symbol(baddts, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 18, 12))
+>foo : Symbol(foo, Decl(declarationEmitExactOptionalPropertyTypesNodeNotReused.ts, 16, 5))
+
diff --git a/...arationEmitExactOptionalPropertyTypesNodeNotReused(exactoptionalpropertytypes=true).types b/...arationEmitExactOptionalPropertyTypesNodeNotReused(exactoptionalpropertytypes=true).types
@@ -0,0 +1,53 @@
+//// [tests/cases/compiler/declarationEmitExactOptionalPropertyTypesNodeNotReused.ts] ////
+
+=== declarationEmitExactOptionalPropertyTypesNodeNotReused.ts ===
+type InexactOptionals<A> = {
+>InexactOptionals : InexactOptionals<A>
+>                 : ^^^^^^^^^^^^^^^^^^^
+
+    [K in keyof A as undefined extends A[K] ? K : never]?: undefined extends A[K]
+    ? A[K] | undefined
+    : A[K];
+} & {
+    [K in keyof A as undefined extends A[K] ? never : K]: A[K];
+};
+
+type In = {
+>In : In
+>   : ^^
+
+    foo?: string;
+>foo : string | undefined
+>    : ^^^^^^^^^^^^^^^^^^
+
+    bar: number;
+>bar : number
+>    : ^^^^^^
+
+    baz: undefined;
+>baz : undefined
+>    : ^^^^^^^^^
+}
+
+type Out = InexactOptionals<In>
+>Out : Out
+>    : ^^^
+
+const foo = <A = {}>() => (x: Out & A) => null
+>foo : <A = {}>() => (x: Out & A) => null
+>    : ^ ^^^^^^^^^^^^^ ^^       ^^^^^^^^^
+><A = {}>() => (x: Out & A) => null : <A = {}>() => (x: Out & A) => null
+>                                   : ^ ^^^^^^^^^^^^^ ^^       ^^^^^^^^^
+>(x: Out & A) => null : (x: Out & A) => null
+>                     : ^ ^^       ^^^^^^^^^
+>x : { foo?: string | undefined; baz?: undefined; } & { bar: number; } & A
+>  : ^^^^^^^^      ^^^^^^^^^^^^^^^^^^^^         ^^^^^^^^^^^^^      ^^^^^^^
+
+export const baddts = foo()
+>baddts : (x: { foo?: string | undefined; baz?: undefined; } & { bar: number; }) => null
+>       : ^ ^^^^^^^^^^      ^^^^^^^^^^^^^^^^^^^^         ^^^^^^^^^^^^^      ^^^^^^^^^^^^
+>foo() : (x: { foo?: string | undefined; baz?: undefined; } & { bar: number; }) => null
+>      : ^ ^^^^^^^^^^      ^^^^^^^^^^^^^^^^^^^^         ^^^^^^^^^^^^^      ^^^^^^^^^^^^
+>foo : <A = {}>() => (x: Out & A) => null
+>    : ^ ^^^^^^^^^^^^^ ^^       ^^^^^^^^^
+