Fixed accidental propagation of caching-related objectFlags

Author: Andarist

src/compiler/checker.ts

@@ -16285,7 +16285,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         let type = unionTypes.get(id);
         if (!type) {
             type = createType(TypeFlags.Union) as UnionType;
-            type.objectFlags = objectFlags | getPropagatingFlagsOfTypes(types, /*excludeKinds*/ TypeFlags.Nullable);
+            type.objectFlags = (objectFlags | getPropagatingFlagsOfTypes(types, /*excludeKinds*/ TypeFlags.Nullable)) & ~(ObjectFlags.IsUnknownLikeUnionComputed | ObjectFlags.IsUnknownLikeUnion);
             type.types = types;
             type.origin = origin;
             type.aliasSymbol = aliasSymbol;

tests/baselines/reference/unknownLikeUnionObjectFlagsNotPropagated.symbols

@@ -0,0 +1,41 @@
+=== tests/cases/compiler/unknownLikeUnionObjectFlagsNotPropagated.ts ===
+// repro from #52475#issuecomment-1411215277
+
+type MyType = {} | null | undefined;
+>MyType : Symbol(MyType, Decl(unknownLikeUnionObjectFlagsNotPropagated.ts, 0, 0))
+
+const myVar: MyType = null as MyType;
+>myVar : Symbol(myVar, Decl(unknownLikeUnionObjectFlagsNotPropagated.ts, 4, 5))
+>MyType : Symbol(MyType, Decl(unknownLikeUnionObjectFlagsNotPropagated.ts, 0, 0))
+>MyType : Symbol(MyType, Decl(unknownLikeUnionObjectFlagsNotPropagated.ts, 0, 0))
+
+myVar?.toLocaleString;
+>myVar?.toLocaleString : Symbol(Object.toLocaleString, Decl(lib.es5.d.ts, --, --))
+>myVar : Symbol(myVar, Decl(unknownLikeUnionObjectFlagsNotPropagated.ts, 4, 5))
+>toLocaleString : Symbol(Object.toLocaleString, Decl(lib.es5.d.ts, --, --))
+
+myVar;
+>myVar : Symbol(myVar, Decl(unknownLikeUnionObjectFlagsNotPropagated.ts, 4, 5))
+
+async function myUnusedFunction() {
+>myUnusedFunction : Symbol(myUnusedFunction, Decl(unknownLikeUnionObjectFlagsNotPropagated.ts, 7, 6))
+
+    const fetch1 = Promise.resolve(['hello', 'world']);
+>fetch1 : Symbol(fetch1, Decl(unknownLikeUnionObjectFlagsNotPropagated.ts, 10, 9))
+>Promise.resolve : Symbol(PromiseConstructor.resolve, Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --))
+>Promise : Symbol(Promise, Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2018.promise.d.ts, --, --))
+>resolve : Symbol(PromiseConstructor.resolve, Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --))
+
+    const [data1] = await Promise.all([fetch1]);
+>data1 : Symbol(data1, Decl(unknownLikeUnionObjectFlagsNotPropagated.ts, 11, 11))
+>Promise.all : Symbol(PromiseConstructor.all, Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --))
+>Promise : Symbol(Promise, Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2018.promise.d.ts, --, --))
+>all : Symbol(PromiseConstructor.all, Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --))
+>fetch1 : Symbol(fetch1, Decl(unknownLikeUnionObjectFlagsNotPropagated.ts, 10, 9))
+
+    data1.length;
+>data1.length : Symbol(Array.length, Decl(lib.es5.d.ts, --, --))
+>data1 : Symbol(data1, Decl(unknownLikeUnionObjectFlagsNotPropagated.ts, 11, 11))
+>length : Symbol(Array.length, Decl(lib.es5.d.ts, --, --))
+}
+

tests/baselines/reference/unknownLikeUnionObjectFlagsNotPropagated.types

@@ -0,0 +1,49 @@
+=== tests/cases/compiler/unknownLikeUnionObjectFlagsNotPropagated.ts ===
+// repro from #52475#issuecomment-1411215277
+
+type MyType = {} | null | undefined;
+>MyType : {} | null | undefined
+>null : null
+
+const myVar: MyType = null as MyType;
+>myVar : MyType
+>null as MyType : MyType
+>null : null
+
+myVar?.toLocaleString;
+>myVar?.toLocaleString : (() => string) | undefined
+>myVar : MyType
+>toLocaleString : (() => string) | undefined
+
+myVar;
+>myVar : MyType
+
+async function myUnusedFunction() {
+>myUnusedFunction : () => Promise<void>
+
+    const fetch1 = Promise.resolve(['hello', 'world']);
+>fetch1 : Promise<string[]>
+>Promise.resolve(['hello', 'world']) : Promise<string[]>
+>Promise.resolve : { (): Promise<void>; <T>(value: T): Promise<Awaited<T>>; <T>(value: T | PromiseLike<T>): Promise<Awaited<T>>; }
+>Promise : PromiseConstructor
+>resolve : { (): Promise<void>; <T>(value: T): Promise<Awaited<T>>; <T>(value: T | PromiseLike<T>): Promise<Awaited<T>>; }
+>['hello', 'world'] : string[]
+>'hello' : "hello"
+>'world' : "world"
+
+    const [data1] = await Promise.all([fetch1]);
+>data1 : string[]
+>await Promise.all([fetch1]) : [string[]]
+>Promise.all([fetch1]) : Promise<[string[]]>
+>Promise.all : { <T>(values: Iterable<T | PromiseLike<T>>): Promise<Awaited<T>[]>; <T extends readonly unknown[] | []>(values: T): Promise<{ -readonly [P in keyof T]: Awaited<T[P]>; }>; }
+>Promise : PromiseConstructor
+>all : { <T>(values: Iterable<T | PromiseLike<T>>): Promise<Awaited<T>[]>; <T extends readonly unknown[] | []>(values: T): Promise<{ -readonly [P in keyof T]: Awaited<T[P]>; }>; }
+>[fetch1] : [Promise<string[]>]
+>fetch1 : Promise<string[]>
+
+    data1.length;
+>data1.length : number
+>data1 : string[]
+>length : number
+}
+

tests/cases/compiler/unknownLikeUnionObjectFlagsNotPropagated.ts

@@ -0,0 +1,18 @@
+// @strict: true
+// @noEmit: true
+// @lib: esnext
+
+// repro from #52475#issuecomment-1411215277
+
+type MyType = {} | null | undefined;
+
+const myVar: MyType = null as MyType;
+
+myVar?.toLocaleString;
+myVar;
+
+async function myUnusedFunction() {
+    const fetch1 = Promise.resolve(['hello', 'world']);
+    const [data1] = await Promise.all([fetch1]);
+    data1.length;
+}