Revise behavior of mapped types with any/keyof any constraints

Author: Andarist

src/compiler/checker.ts

@@ -14127,7 +14127,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             cb(getLiteralTypeFromProperty(prop, include));
         }
         if (type.flags & TypeFlags.Any) {
-            cb(stringType);
+            forEachType(stringsOnly ? stringType : stringNumberSymbolType, cb);
         }
         else {
             for (const info of getIndexInfosOfType(type)) {
@@ -14166,7 +14166,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
 
         function addMemberForKeyType(keyType: Type) {
             const propNameType = nameType ? instantiateType(nameType, appendTypeMapping(type.mapper, typeParameter, keyType)) : keyType;
-            forEachType(propNameType, t => addMemberForKeyTypeWorker(keyType, t));
+            forEachType(keyType.flags & TypeFlags.Any ? stringNumberSymbolType : propNameType, t => addMemberForKeyTypeWorker(keyType, t));
         }
 
         function addMemberForKeyTypeWorker(keyType: Type, propNameType: Type) {
@@ -14201,10 +14201,8 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     members.set(propName, prop);
                 }
             }
-            else if (isValidIndexKeyType(propNameType) || propNameType.flags & (TypeFlags.Any | TypeFlags.Enum)) {
-                const indexKeyType = propNameType.flags & (TypeFlags.Any | TypeFlags.String) ? stringType :
-                    propNameType.flags & (TypeFlags.Number | TypeFlags.Enum) ? numberType :
-                    propNameType;
+            else if (isValidIndexKeyType(propNameType) || propNameType.flags & TypeFlags.Enum) {
+                const indexKeyType = propNameType.flags & (TypeFlags.Number | TypeFlags.Enum) ? numberType : propNameType;
                 const propType = instantiateType(templateType, appendTypeMapping(type.mapper, typeParameter, keyType));
                 const modifiersIndexInfo = getApplicableIndexInfo(modifiersType, propNameType);
                 const isReadonly = !!(templateModifiers & MappedTypeModifiers.IncludeReadonly ||

tests/baselines/reference/mappedTypeWithAny.errors.txt

@@ -77,4 +77,10 @@ mappedTypeWithAny.ts(53,5): error TS2322: Type 'string[]' is not assignable to t
     type Evolver<T extends Evolvable<any> = any> = {
       [key in keyof Partial<T>]: never;
     };
+    
+    // https://github.com/microsoft/TypeScript/issues/61203
+    type Obj61203 = { [k in keyof any]: number };
+    declare const obj61203: Obj61203;
+    declare const key61203: keyof Obj61203;
+    obj61203[key61203]; // ok
 

tests/baselines/reference/mappedTypeWithAny.js

@@ -63,6 +63,12 @@ type Evolvable<E extends Evolver> = {
 type Evolver<T extends Evolvable<any> = any> = {
   [key in keyof Partial<T>]: never;
 };
+
+// https://github.com/microsoft/TypeScript/issues/61203
+type Obj61203 = { [k in keyof any]: number };
+declare const obj61203: Obj61203;
+declare const key61203: keyof Obj61203;
+obj61203[key61203]; // ok
 
 
 //// [mappedTypeWithAny.js]
@@ -79,6 +85,7 @@ function bar(arrayish, objectish, indirectArrayish) {
 }
 var abc = stringifyArray(void 0);
 var def = stringifyPair(void 0);
+obj61203[key61203]; // ok
 
 
 //// [mappedTypeWithAny.d.ts]
@@ -128,3 +135,8 @@ type Evolvable<E extends Evolver> = {
 type Evolver<T extends Evolvable<any> = any> = {
     [key in keyof Partial<T>]: never;
 };
+type Obj61203 = {
+    [k in keyof any]: number;
+};
+declare const obj61203: Obj61203;
+declare const key61203: keyof Obj61203;

tests/baselines/reference/mappedTypeWithAny.symbols

@@ -177,3 +177,20 @@ type Evolver<T extends Evolvable<any> = any> = {
 
 };
 
+// https://github.com/microsoft/TypeScript/issues/61203
+type Obj61203 = { [k in keyof any]: number };
+>Obj61203 : Symbol(Obj61203, Decl(mappedTypeWithAny.ts, 61, 2))
+>k : Symbol(k, Decl(mappedTypeWithAny.ts, 64, 19))
+
+declare const obj61203: Obj61203;
+>obj61203 : Symbol(obj61203, Decl(mappedTypeWithAny.ts, 65, 13))
+>Obj61203 : Symbol(Obj61203, Decl(mappedTypeWithAny.ts, 61, 2))
+
+declare const key61203: keyof Obj61203;
+>key61203 : Symbol(key61203, Decl(mappedTypeWithAny.ts, 66, 13))
+>Obj61203 : Symbol(Obj61203, Decl(mappedTypeWithAny.ts, 61, 2))
+
+obj61203[key61203]; // ok
+>obj61203 : Symbol(obj61203, Decl(mappedTypeWithAny.ts, 65, 13))
+>key61203 : Symbol(key61203, Decl(mappedTypeWithAny.ts, 66, 13))
+

tests/baselines/reference/mappedTypeWithAny.types

@@ -24,8 +24,8 @@ declare let x2: { [P in string]: Item };
 >   : ^^^^^^^^^^^^^^^^^^^^^^
 
 declare let x3: { [P in keyof any]: Item };
->x3 : { [x: string]: Item; }
->   : ^^^^^^^^^^^^^^^^^^^^^^
+>x3 : { [x: string]: Item; [x: number]: Item; [x: symbol]: Item; }
+>   : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 declare let x4: ItemMap<any>;
 >x4 : ItemMap<any>
@@ -197,3 +197,24 @@ type Evolver<T extends Evolvable<any> = any> = {
   [key in keyof Partial<T>]: never;
 };
 
+// https://github.com/microsoft/TypeScript/issues/61203
+type Obj61203 = { [k in keyof any]: number };
+>Obj61203 : Obj61203
+>         : ^^^^^^^^
+
+declare const obj61203: Obj61203;
+>obj61203 : Obj61203
+>         : ^^^^^^^^
+
+declare const key61203: keyof Obj61203;
+>key61203 : string | number | symbol
+>         : ^^^^^^^^^^^^^^^^^^^^^^^^
+
+obj61203[key61203]; // ok
+>obj61203[key61203] : number
+>                   : ^^^^^^
+>obj61203 : Obj61203
+>         : ^^^^^^^^
+>key61203 : string | number | symbol
+>         : ^^^^^^^^^^^^^^^^^^^^^^^^
+

tests/cases/conformance/types/mapped/mappedTypeWithAny.ts

@@ -63,3 +63,9 @@ type Evolvable<E extends Evolver> = {
 type Evolver<T extends Evolvable<any> = any> = {
   [key in keyof Partial<T>]: never;
 };
+
+// https://github.com/microsoft/TypeScript/issues/61203
+type Obj61203 = { [k in keyof any]: number };
+declare const obj61203: Obj61203;
+declare const key61203: keyof Obj61203;
+obj61203[key61203]; // ok