Generic conditional type X extends any ? X : X does not allow generic assignment of X

[eibens]

TypeScript Version: Nightly

Search Terms:
generic, conditional type, cannot be assigned, generic return value

Expected behavior:
A value of type X is a valid return value for a function returning Always<X>, since the latter is a generic conditional type that always evaluates to X.

Actual behavior:
Does not compile. Error message:
Type 'X' is not assignable to type 'Always<X>'. (2322)

Related Issues:
#31751 seems to be more about never type semantics.

Code
You can substitute any type for any in the definition below and it will fail regardless.

export type Always<X> = X extends any ? X : X
const f = <X>(): Always<X> => /*error*/ null as unknown as X /*error*/

Output

const f = () => null;

Compiler Options

{
  "compilerOptions": {
    "noImplicitAny": true,
    "strictNullChecks": true,
    "strictFunctionTypes": true,
    "strictPropertyInitialization": true,
    "strictBindCallApply": true,
    "noImplicitThis": true,
    "noImplicitReturns": true,
    "useDefineForClassFields": false,
    "alwaysStrict": true,
    "allowUnreachableCode": false,
    "allowUnusedLabels": false,
    "downlevelIteration": false,
    "noEmitHelpers": false,
    "noLib": false,
    "noStrictGenericChecks": false,
    "noUnusedLocals": false,
    "noUnusedParameters": false,
    "esModuleInterop": true,
    "preserveConstEnums": false,
    "removeComments": false,
    "skipLibCheck": false,
    "checkJs": false,
    "allowJs": false,
    "declaration": true,
    "experimentalDecorators": false,
    "emitDecoratorMetadata": false,
    "target": "ES2017",
    "module": "ESNext"
  }
}

Playground Link: Provided

[eibens]

#37279 is actually extremely similar and describes how I encountered this problem in the first place. I guess since X may also be a type union it is working as intended. Same solution applies:

export type Always<X> = [X] extends [any] ? X : X
const f = <X>(): Always<X> => null as unknown as X