TypeScript/tests/baselines/reference/conditionalTypeAssignabilityWhenDeferred.types

=== tests/cases/compiler/conditionalTypeAssignabilityWhenDeferred.ts ===
export type FilterPropsByType<T, TT> = {
>FilterPropsByType : FilterPropsByType<T, TT>

  [K in keyof T]: T[K] extends TT ? K : never
}[keyof T];

function select<
>select : <T extends string | number, TList extends object, TValueProp extends FilterPropsByType<TList, T>>(property: T, list: TList[], valueProp: TValueProp) => void

  T extends string | number,
  TList extends object,
  TValueProp extends FilterPropsByType<TList, T>
>(property: T, list: TList[], valueProp: TValueProp) {}
>property : T
>list : TList[]
>valueProp : TValueProp

export function func<XX extends string>(x: XX, tipos: { value: XX }[]) {
>func : <XX extends string>(x: XX, tipos: {    value: XX;}[]) => void
>x : XX
>tipos : { value: XX; }[]
>value : XX

  select(x, tipos, "value");
>select(x, tipos, "value") : void
>select : <T extends string | number, TList extends object, TValueProp extends FilterPropsByType<TList, T>>(property: T, list: TList[], valueProp: TValueProp) => void
>x : XX
>tipos : { value: XX; }[]
>"value" : "value"
}

declare function onlyNullablePlease<T extends null extends T ? any : never>(
>onlyNullablePlease : <T extends null extends T ? any : never>(value: T) => void
>null : null

  value: T
>value : T

): void;

declare function onlyNullablePlease2<
>onlyNullablePlease2 : <T extends [null] extends [T] ? any : never>(value: T) => void

  T extends [null] extends [T] ? any : never
>null : null

>(value: T): void;
>value : T

declare var z: string | null;
>z : string | null
>null : null

onlyNullablePlease(z); // works as expected
>onlyNullablePlease(z) : void
>onlyNullablePlease : <T extends null extends T ? any : never>(value: T) => void
>z : string | null

onlyNullablePlease2(z); // works as expected
>onlyNullablePlease2(z) : void
>onlyNullablePlease2 : <T extends [null] extends [T] ? any : never>(value: T) => void
>z : string | null

declare var y: string;
>y : string

onlyNullablePlease(y); // error as expected
>onlyNullablePlease(y) : void
>onlyNullablePlease : <T extends null extends T ? any : never>(value: T) => void
>y : string

onlyNullablePlease2(y); // error as expected
>onlyNullablePlease2(y) : void
>onlyNullablePlease2 : <T extends [null] extends [T] ? any : never>(value: T) => void
>y : string

function f<T>(t: T) {
>f : <T>(t: T) => void
>t : T

  var x: T | null = Math.random() > 0.5 ? null : t;
>x : T | null
>null : null
>Math.random() > 0.5 ? null : t : T | null
>Math.random() > 0.5 : boolean
>Math.random() : number
>Math.random : () => number
>Math : Math
>random : () => number
>0.5 : 0.5
>null : null
>t : T

  onlyNullablePlease(x); // should work
>onlyNullablePlease(x) : void
>onlyNullablePlease : <T extends null extends T ? any : never>(value: T) => void
>x : T | null

  onlyNullablePlease2(x); // should work
>onlyNullablePlease2(x) : void
>onlyNullablePlease2 : <T extends [null] extends [T] ? any : never>(value: T) => void
>x : T | null
}

function f2<T>(t1: { x: T; y: T }, t2: T extends T ? { x: T; y: T } : never) {
>f2 : <T>(t1: {    x: T;    y: T;}, t2: T extends T ? {    x: T;    y: T;} : never) => void
>t1 : { x: T; y: T; }
>x : T
>y : T
>t2 : T extends T ? { x: T; y: T; } : never
>x : T
>y : T

  t1 = t2; // OK
>t1 = t2 : T extends T ? { x: T; y: T; } : never
>t1 : { x: T; y: T; }
>t2 : T extends T ? { x: T; y: T; } : never

  t2 = t1; // should fail
>t2 = t1 : { x: T; y: T; }
>t2 : T extends T ? { x: T; y: T; } : never
>t1 : { x: T; y: T; }
}

type Foo<T> = T extends true ? string : "a";
>Foo : Foo<T>
>true : true

function test<T>(x: Foo<T>, s: string) {
>test : <T>(x: Foo<T>, s: string) => void
>x : Foo<T>
>s : string

  x = "a"; // Currently an error, should be ok
>x = "a" : "a"
>x : Foo<T>
>"a" : "a"

  x = s; // Error
>x = s : string
>x : Foo<T>
>s : string
}

// #26933
type Distributive<T> = T extends { a: number } ? { a: number } : { b: number };
>Distributive : Distributive<T>
>a : number
>a : number
>b : number

function testAssignabilityToConditionalType<T>() {
>testAssignabilityToConditionalType : <T>() => void

  const o = { a: 1, b: 2 };
>o : { a: number; b: number; }
>{ a: 1, b: 2 } : { a: number; b: number; }
>a : number
>1 : 1
>b : number
>2 : 2

  const x: [T] extends [string]
>x : [T] extends [string] ? { y: number; } : { a: number; b: number; }

    ? { y: number }
>y : number

    : { a: number; b: number } = undefined!;
>a : number
>b : number
>undefined! : never
>undefined : undefined

  // Simple case: OK
  const o1: [T] extends [number] ? { a: number } : { b: number } = o;
>o1 : [T] extends [number] ? { a: number; } : { b: number; }
>a : number
>b : number
>o : { a: number; b: number; }

  // Simple case where source happens to be a conditional type: also OK
  const x1: [T] extends [number]
>x1 : [T] extends [number] ? [T] extends [string] ? { y: number; } : { a: number; } : [T] extends [string] ? { y: number; } : { b: number; }

    ? ([T] extends [string] ? { y: number } : { a: number })
>y : number
>a : number

    : ([T] extends [string] ? { y: number } : { b: number }) = x;
>y : number
>b : number
>x : [T] extends [string] ? { y: number; } : { a: number; b: number; }

  // Infer type parameters: no good
  const o2: [T] extends [[infer U]] ? U : { b: number } = o;
>o2 : [T] extends [[infer U]] ? U : { b: number; }
>b : number
>o : { a: number; b: number; }

  // The next 4 are arguable - if you choose to ignore the `never` distribution case,
  // then they're all good. The `never` case _is_ a bit of an outlier - we say distributive types
  // look approximately like the sum of their branches, but the `never` case bucks that.
  // There's an argument for the result of dumping `never` into a distributive conditional
  // being not `never`, but instead the intersection of the branches - a much more precise bound
  // on that "impossible" input.

  // Distributive where T might instantiate to never: no good
  const o3: Distributive<T> = o;
>o3 : Distributive<T>
>o : { a: number; b: number; }

  // Distributive where T & string might instantiate to never: also no good
  const o4: Distributive<T & string> = o;
>o4 : Distributive<T & string>
>o : { a: number; b: number; }

  // Distributive where {a: T} cannot instantiate to never: OK
  const o5: Distributive<{ a: T }> = o;
>o5 : Distributive<{ a: T; }>
>a : T
>o : { a: number; b: number; }

  // Distributive where check type is a conditional which returns a non-never type upon instantiation with `never` but can still return never otherwise: no good
  const o6: Distributive<[T] extends [never] ? { a: number } : never> = o;
>o6 : Distributive<[T] extends [never] ? { a: number; } : never>
>a : number
>o : { a: number; b: number; }
}

type Wrapped<T> = { ___secret: T };
>Wrapped : Wrapped<T>
>___secret : T

type Unwrap<T> = T extends Wrapped<infer U> ? U : T;
>Unwrap : Unwrap<T>

declare function set<T, K extends keyof T>(
>set : <T, K extends keyof T>(obj: T, key: K, value: Unwrap<T[K]>) => Unwrap<T[K]>

  obj: T,
>obj : T

  key: K,
>key : K

  value: Unwrap<T[K]>
>value : Unwrap<T[K]>

): Unwrap<T[K]>;

class Foo2 {
>Foo2 : Foo2

  prop!: Wrapped<string>;
>prop : Wrapped<string>

  method() {
>method : () => void

    set(this, "prop", "hi"); // <-- type error
>set(this, "prop", "hi") : Unwrap<this["prop"]>
>set : <T, K extends keyof T>(obj: T, key: K, value: Unwrap<T[K]>) => Unwrap<T[K]>
>this : this
>"prop" : "prop"
>"hi" : "hi"
  }
}

set(new Foo2(), "prop", "hi"); // <-- typechecks
>set(new Foo2(), "prop", "hi") : string
>set : <T, K extends keyof T>(obj: T, key: K, value: Unwrap<T[K]>) => Unwrap<T[K]>
>new Foo2() : Foo2
>Foo2 : typeof Foo2
>"prop" : "prop"
>"hi" : "hi"

type InferBecauseWhyNot<T> = [T] extends [(p: infer P1) => any]
>InferBecauseWhyNot : InferBecauseWhyNot<T>
>p : P1

  ? P1 | T
  : never;

function f3<Q extends (arg: any) => any>(x: Q): InferBecauseWhyNot<Q> {
>f3 : <Q extends (arg: any) => any>(x: Q) => InferBecauseWhyNot<Q>
>arg : any
>x : Q

  return x;
>x : Q
}

type InferBecauseWhyNotDistributive<T> = T extends (p: infer P1) => any
>InferBecauseWhyNotDistributive : InferBecauseWhyNotDistributive<T>
>p : P1

  ? P1 | T
  : never;

function f4<Q extends (arg: any) => any>(
>f4 : <Q extends (arg: any) => any>(x: Q) => InferBecauseWhyNotDistributive<Q>
>arg : any

  x: Q
>x : Q

): InferBecauseWhyNotDistributive<Q> {
  return x; // should fail
>x : Q
}