Add regression test

Author: ahejlsberg

tests/baselines/reference/primitiveUnionDetection.js

@@ -0,0 +1,19 @@
+//// [primitiveUnionDetection.ts]
+// Repro from #46624
+
+export type Kind = "one" | "two" | "three";
+
+declare function getInterfaceFromString<T extends Kind>(options?: { type?: T } & { type?: Kind }): T;
+
+const result = getInterfaceFromString({ type: 'two' });
+
+
+//// [primitiveUnionDetection.js]
+"use strict";
+// Repro from #46624
+exports.__esModule = true;
+var result = getInterfaceFromString({ type: 'two' });
+
+
+//// [primitiveUnionDetection.d.ts]
+export declare type Kind = "one" | "two" | "three";

tests/baselines/reference/primitiveUnionDetection.symbols

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+=== tests/cases/compiler/primitiveUnionDetection.ts ===
+// Repro from #46624
+
+export type Kind = "one" | "two" | "three";
+>Kind : Symbol(Kind, Decl(primitiveUnionDetection.ts, 0, 0))
+
+declare function getInterfaceFromString<T extends Kind>(options?: { type?: T } & { type?: Kind }): T;
+>getInterfaceFromString : Symbol(getInterfaceFromString, Decl(primitiveUnionDetection.ts, 2, 43))
+>T : Symbol(T, Decl(primitiveUnionDetection.ts, 4, 40))
+>Kind : Symbol(Kind, Decl(primitiveUnionDetection.ts, 0, 0))
+>options : Symbol(options, Decl(primitiveUnionDetection.ts, 4, 56))
+>type : Symbol(type, Decl(primitiveUnionDetection.ts, 4, 67))
+>T : Symbol(T, Decl(primitiveUnionDetection.ts, 4, 40))
+>type : Symbol(type, Decl(primitiveUnionDetection.ts, 4, 82))
+>Kind : Symbol(Kind, Decl(primitiveUnionDetection.ts, 0, 0))
+>T : Symbol(T, Decl(primitiveUnionDetection.ts, 4, 40))
+
+const result = getInterfaceFromString({ type: 'two' });
+>result : Symbol(result, Decl(primitiveUnionDetection.ts, 6, 5))
+>getInterfaceFromString : Symbol(getInterfaceFromString, Decl(primitiveUnionDetection.ts, 2, 43))
+>type : Symbol(type, Decl(primitiveUnionDetection.ts, 6, 39))
+

tests/baselines/reference/primitiveUnionDetection.types

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+=== tests/cases/compiler/primitiveUnionDetection.ts ===
+// Repro from #46624
+
+export type Kind = "one" | "two" | "three";
+>Kind : Kind
+
+declare function getInterfaceFromString<T extends Kind>(options?: { type?: T } & { type?: Kind }): T;
+>getInterfaceFromString : <T extends Kind>(options?: ({ type?: T | undefined; } & { type?: Kind | undefined; }) | undefined) => T
+>options : ({ type?: T | undefined; } & { type?: Kind | undefined; }) | undefined
+>type : T | undefined
+>type : Kind | undefined
+
+const result = getInterfaceFromString({ type: 'two' });
+>result : "two"
+>getInterfaceFromString({ type: 'two' }) : "two"
+>getInterfaceFromString : <T extends Kind>(options?: ({ type?: T | undefined; } & { type?: Kind | undefined; }) | undefined) => T
+>{ type: 'two' } : { type: "two"; }
+>type : "two"
+>'two' : "two"
+

tests/cases/compiler/primitiveUnionDetection.ts

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+// @strict: true
+// @declaration: true
+
+// Repro from #46624
+
+export type Kind = "one" | "two" | "three";
+
+declare function getInterfaceFromString<T extends Kind>(options?: { type?: T } & { type?: Kind }): T;
+
+const result = getInterfaceFromString({ type: 'two' });