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=== tests/cases/compiler/identityRelationNeverTypes.ts ===
// Repro from #47996
type Equals<A, B> = (<T>() => T extends B ? 1 : 0) extends (<T>() => T extends A ? 1 : 0) ? true : false;
>Equals : Equals<A, B>
>true : true
>false : false
declare class State<TContext> {
>State : State<TContext>
_context: TContext;
>_context : TContext
_value: string;
>_value : string
matches<TSV extends string>(stateValue: TSV): this is State<TContext> & { value: TSV };
>matches : <TSV extends string>(stateValue: TSV) => this is State<TContext> & { value: TSV; }
>stateValue : TSV
>value : TSV
}
function f1(state: State<{ foo: number }>) {
>f1 : (state: State<{ foo: number;}>) => void
>state : State<{ foo: number; }>
>foo : number
if (state.matches('a') && state.matches('a.b')) {
>state.matches('a') && state.matches('a.b') : boolean
>state.matches('a') : boolean
>state.matches : <TSV extends string>(stateValue: TSV) => this is State<{ foo: number; }> & { value: TSV; }
>state : State<{ foo: number; }>
>matches : <TSV extends string>(stateValue: TSV) => this is State<{ foo: number; }> & { value: TSV; }
>'a' : "a"
>state.matches('a.b') : boolean
>state.matches : <TSV extends string>(stateValue: TSV) => this is State<{ foo: number; }> & { value: TSV; }
>state : State<{ foo: number; }> & { value: "a"; }
>matches : <TSV extends string>(stateValue: TSV) => this is State<{ foo: number; }> & { value: TSV; }
>'a.b' : "a.b"
state; // never
>state : never
type T1 = Equals<typeof state, never>; // true
>T1 : true
>state : never
type T2 = Equals<never, never>; // true
>T2 : true
}
}
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