Include index signatures for tagged primitives in keyof (microsoft#45773)

* Properly include tagged primitive types in keyof

* Add regression test

Author: ahejlsberg

src/compiler/checker.ts

@@ -12789,7 +12789,7 @@ namespace ts {
 
         function isValidIndexKeyType(type: Type): boolean {
             return !!(type.flags & (TypeFlags.String | TypeFlags.Number | TypeFlags.ESSymbol)) || isPatternLiteralType(type) ||
-                !!(type.flags & TypeFlags.Intersection) && !isGenericIndexType(type) && !isGenericObjectType(type) && some((type as IntersectionType).types, isValidIndexKeyType);
+                !!(type.flags & TypeFlags.Intersection) && !isGenericType(type) && some((type as IntersectionType).types, isValidIndexKeyType);
         }
 
         function getConstraintDeclaration(type: TypeParameter): TypeNode | undefined {
@@ -14545,10 +14545,14 @@ namespace ts {
             return neverType;
         }
 
+        function isKeyTypeIncluded(keyType: Type, include: TypeFlags): boolean {
+            return !!(keyType.flags & include || keyType.flags & TypeFlags.Intersection && some((keyType as IntersectionType).types, t => isKeyTypeIncluded(t, include)));
+        }
+
         function getLiteralTypeFromProperties(type: Type, include: TypeFlags, includeOrigin: boolean) {
             const origin = includeOrigin && (getObjectFlags(type) & (ObjectFlags.ClassOrInterface | ObjectFlags.Reference) || type.aliasSymbol) ? createOriginIndexType(type) : undefined;
             const propertyTypes = map(getPropertiesOfType(type), prop => getLiteralTypeFromProperty(prop, include));
-            const indexKeyTypes = map(getIndexInfosOfType(type), info => info !== enumNumberIndexInfo && info.keyType.flags & include ?
+            const indexKeyTypes = map(getIndexInfosOfType(type), info => info !== enumNumberIndexInfo && isKeyTypeIncluded(info.keyType, include) ?
                 info.keyType === stringType && include & TypeFlags.Number ? stringOrNumberType : info.keyType : neverType);
             return getUnionType(concatenate(propertyTypes, indexKeyTypes), UnionReduction.Literal,
                 /*aliasSymbol*/ undefined, /*aliasTypeArguments*/ undefined, origin);

tests/baselines/reference/indexSignatures1.errors.txt

@@ -507,4 +507,13 @@ tests/cases/conformance/types/members/indexSignatures1.ts(312,43): error TS2322:
                                               ~~~~~~~~~~~~~~~
 !!! error TS2322: Type '{ [sym]: string; }' is not assignable to type '{ [key: number]: string; }'.
 !!! error TS2322:   Object literal may only specify known properties, and '[sym]' does not exist in type '{ [key: number]: string; }'.
+    
+    // Repro from #45772
+    
+    type Id = string & { __tag: 'id '};
+    type Rec1 = { [key: Id]: number };
+    type Rec2 = Record<Id, number>;
+    
+    type K1 = keyof Rec1;  // Id
+    type K2 = keyof Rec2;  // Id
 

tests/baselines/reference/indexSignatures1.js

@@ -311,6 +311,15 @@ const aa: AA = { [sym]: '123' };
 const obj1: { [key: symbol]: string } = { [sym]: 'hello '};
 const obj2: { [key: string]: string } = { [sym]: 'hello '};  // Permitted for backwards compatibility
 const obj3: { [key: number]: string } = { [sym]: 'hello '};  // Error
+
+// Repro from #45772
+
+type Id = string & { __tag: 'id '};
+type Rec1 = { [key: Id]: number };
+type Rec2 = Record<Id, number>;
+
+type K1 = keyof Rec1;  // Id
+type K2 = keyof Rec2;  // Id
 
 
 //// [indexSignatures1.js]
@@ -660,3 +669,12 @@ declare const obj2: {
 declare const obj3: {
     [key: number]: string;
 };
+declare type Id = string & {
+    __tag: 'id ';
+};
+declare type Rec1 = {
+    [key: Id]: number;
+};
+declare type Rec2 = Record<Id, number>;
+declare type K1 = keyof Rec1;
+declare type K2 = keyof Rec2;

tests/baselines/reference/indexSignatures1.symbols

@@ -899,3 +899,27 @@ const obj3: { [key: number]: string } = { [sym]: 'hello '};  // Error
 >[sym] : Symbol([sym], Decl(indexSignatures1.ts, 311, 41))
 >sym : Symbol(sym, Decl(indexSignatures1.ts, 2, 5))
 
+// Repro from #45772
+
+type Id = string & { __tag: 'id '};
+>Id : Symbol(Id, Decl(indexSignatures1.ts, 311, 59))
+>__tag : Symbol(__tag, Decl(indexSignatures1.ts, 315, 20))
+
+type Rec1 = { [key: Id]: number };
+>Rec1 : Symbol(Rec1, Decl(indexSignatures1.ts, 315, 35))
+>key : Symbol(key, Decl(indexSignatures1.ts, 316, 15))
+>Id : Symbol(Id, Decl(indexSignatures1.ts, 311, 59))
+
+type Rec2 = Record<Id, number>;
+>Rec2 : Symbol(Rec2, Decl(indexSignatures1.ts, 316, 34))
+>Record : Symbol(Record, Decl(lib.es5.d.ts, --, --))
+>Id : Symbol(Id, Decl(indexSignatures1.ts, 311, 59))
+
+type K1 = keyof Rec1;  // Id
+>K1 : Symbol(K1, Decl(indexSignatures1.ts, 317, 31))
+>Rec1 : Symbol(Rec1, Decl(indexSignatures1.ts, 315, 35))
+
+type K2 = keyof Rec2;  // Id
+>K2 : Symbol(K2, Decl(indexSignatures1.ts, 319, 21))
+>Rec2 : Symbol(Rec2, Decl(indexSignatures1.ts, 316, 34))
+

tests/baselines/reference/indexSignatures1.types

@@ -1051,3 +1051,22 @@ const obj3: { [key: number]: string } = { [sym]: 'hello '};  // Error
 >sym : unique symbol
 >'hello ' : "hello "
 
+// Repro from #45772
+
+type Id = string & { __tag: 'id '};
+>Id : Id
+>__tag : "id "
+
+type Rec1 = { [key: Id]: number };
+>Rec1 : Rec1
+>key : Id
+
+type Rec2 = Record<Id, number>;
+>Rec2 : Rec2
+
+type K1 = keyof Rec1;  // Id
+>K1 : Id
+
+type K2 = keyof Rec2;  // Id
+>K2 : Id
+

tests/cases/conformance/types/members/indexSignatures1.ts

@@ -314,3 +314,12 @@ const aa: AA = { [sym]: '123' };
 const obj1: { [key: symbol]: string } = { [sym]: 'hello '};
 const obj2: { [key: string]: string } = { [sym]: 'hello '};  // Permitted for backwards compatibility
 const obj3: { [key: number]: string } = { [sym]: 'hello '};  // Error
+
+// Repro from #45772
+
+type Id = string & { __tag: 'id '};
+type Rec1 = { [key: Id]: number };
+type Rec2 = Record<Id, number>;
+
+type K1 = keyof Rec1;  // Id
+type K2 = keyof Rec2;  // Id