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=== tests/cases/compiler/varianceMeasurement.ts ===
// The type below should be invariant in T but is measured as covariant because
// we don't analyze recursive references.
interface Foo1<T> {
x: T;
>x : T
y: Foo1<(arg: T) => void>;
>y : Foo1<(arg: T) => void>
>arg : T
}
declare const f10: Foo1<string>;
>f10 : Foo1<string>
const f11: Foo1<'a'> = f10;
>f11 : Foo1<"a">
>f10 : Foo1<string>
const f12: Foo1<unknown> = f10;
>f12 : Foo1<unknown>
>f10 : Foo1<string>
// The type below is invariant in T and is measured as such.
interface Foo2<T> {
x: T;
>x : T
y: { x: (arg: T) => void, y: Foo2<(arg: T) => void>; }
>y : { x: (arg: T) => void; y: Foo2<(arg: T) => void>; }
>x : (arg: T) => void
>arg : T
>y : Foo2<(arg: T) => void>
>arg : T
}
declare const f20: Foo2<string>;
>f20 : Foo2<string>
const f21: Foo2<'a'> = f20;
>f21 : Foo2<"a">
>f20 : Foo2<string>
const f22: Foo2<unknown> = f20;
>f22 : Foo2<unknown>
>f20 : Foo2<string>
// The type below should be invariant in T but is measured as covariant because
// we don't analyze recursive references.
type Foo3<T> = {
>Foo3 : Foo3<T>
x: T;
>x : T
y: Foo3<(arg: T) => void>;
>y : Foo3<(arg: T) => void>
>arg : T
}
declare const f30: Foo3<string>;
>f30 : Foo3<string>
const f31: Foo3<'a'> = f30;
>f31 : Foo3<"a">
>f30 : Foo3<string>
const f32: Foo3<unknown> = f30;
>f32 : Foo3<unknown>
>f30 : Foo3<string>
// The type below is invariant in T and is measured as such.
type Foo4<T> = {
>Foo4 : Foo4<T>
x: T;
>x : T
y: { x: (arg: T) => void, y: Foo4<(arg: T) => void>; }
>y : { x: (arg: T) => void; y: Foo4<(arg: T) => void>; }
>x : (arg: T) => void
>arg : T
>y : Foo4<(arg: T) => void>
>arg : T
}
declare const f40: Foo4<string>;
>f40 : Foo4<string>
const f41: Foo4<'a'> = f40;
>f41 : Foo4<"a">
>f40 : Foo4<string>
const f42: Foo4<unknown> = f40;
>f42 : Foo4<unknown>
>f40 : Foo4<string>
// Repro from #3580
interface Fn<A, B> {
(a: A): B;
>a : A
then<C>(next: Fn<B, C>): Fn<A, C>;
>then : <C>(next: Fn<B, C>) => Fn<A, C>
>next : Fn<B, C>
}
declare const fn: Fn<string, number>;
>fn : Fn<string, number>
// Contravariant in A
const fn1: Fn<unknown, number> = fn; // Error
>fn1 : Fn<unknown, number>
>fn : Fn<string, number>
const fn2: Fn<'a', number> = fn;
>fn2 : Fn<"a", number>
>fn : Fn<string, number>
// Covariant in B
const fn3: Fn<string, unknown> = fn;
>fn3 : Fn<string, unknown>
>fn : Fn<string, number>
const fn4: Fn<string, 0> = fn; // Error
>fn4 : Fn<string, 0>
>fn : Fn<string, number>
// Repro from #39947
interface I<Dummy, V> {
c: C<Dummy, V>;
>c : C<Dummy, V>
}
class C<Dummy, V> {
>C : C<Dummy, V>
declare sub: I<Dummy, V>;
>sub : I<Dummy, V>
declare covariance: V;
>covariance : V
}
const c1: C<unknown, string> = new C<unknown, number>(); // Error
>c1 : C<unknown, string>
>new C<unknown, number>() : C<unknown, number>
>C : typeof C
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