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Add branch awareness and tests for the type of 'alt'
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‎index.d.ts

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@@ -86,10 +86,38 @@ export function after(duration: number): <R>(value: R) => Resolved<R>
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export function and<L, R>(left: FutureInstance<L, R>): (right: FutureInstance<L, any>) => FutureInstance<L, R>
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/** Logical or for Futures. See https://github.com/fluture-js/Fluture#alt */
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export function alt<L, R>(left: FutureInstance<L, R>): (right: FutureInstance<L, R>) => FutureInstance<L, R>
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/** Race two ConcurrentFutures. See https://github.com/fluture-js/Fluture#alt */
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export function alt<L, R>(left: ConcurrentFutureInstance<L, R>): (right: ConcurrentFutureInstance<L, R>) => ConcurrentFutureInstance<L, R>
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export const alt: {
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<F extends AnyFuture, S extends AnyFuture>(second: F extends Never ? S : never): (first: F) => Never
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<F extends AnyFuture, S extends AnyFuture>(second: F extends Rejected<unknown> ? S : never): (first: F) => S
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<F extends AnyFuture, S extends AnyFuture>(second: F extends Resolved<unknown> ? S : never): (first: F) => F
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<L>(second: Rejected<L>): {
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(first: Never): Never
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(first: Rejected<any>): Rejected<L>
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<R>(first: Resolved<R>): Resolved<R>
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<R>(first: Uncertain<any, R>): Uncertain<L, R>
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}
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<L, R>(second: Uncertain<L, R>): {
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<T>(first: Resolved<T>): Resolved<T>
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(first: Rejected<any>): Uncertain<L, R>
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(first: Uncertain<any, R>): Uncertain<L, R>
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}
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(second: ConcurrentNever): <L, R>(first: ConcurrentUncertain<L, R>) => ConcurrentUncertain<L, R>
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<L>(second: ConcurrentRejected<L>): {
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<R>(first: ConcurrentResolved<R>): ConcurrentUncertain<L, R>
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<R>(first: ConcurrentUncertain<L, R>): ConcurrentUncertain<L, R>
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}
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<R>(second: ConcurrentResolved<R>): {
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<L>(first: ConcurrentRejected<L>): ConcurrentUncertain<L, R>
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<L>(first: ConcurrentUncertain<L, R>): ConcurrentUncertain<L, R>
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}
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<L, R>(second: ConcurrentUncertain<L, R>): (first: ConcurrentUncertain<L, R>) => ConcurrentUncertain<L, R>
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}
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/** Apply the function in the right Future to the value in the left Future. See https://github.com/fluture-js/Fluture#ap */
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export function ap<L, RA>(value: FutureInstance<L, RA>): <RB>(apply: FutureInstance<L, (value: RA) => RB>) => FutureInstance<L, RB>

‎test/types/alt.test-d.ts

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import {expectType, expectError} from 'tsd';
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import * as fl from '../../index.js';
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const fsn: fl.FutureInstance<string, number> = fl.resolve (42);
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const fns: fl.FutureInstance<number, string> = fl.resolve ('a');
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// Standard usage on Future instances.
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expectType<fl.Never> (fl.alt (fl.never) (fl.never));
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expectType<fl.Never> (fl.alt (fl.reject ('a')) (fl.never));
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expectType<fl.Never> (fl.alt (fl.resolve ('a')) (fl.never));
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expectType<fl.Never> (fl.alt (fl.never) (fl.reject ('a')));
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expectType<fl.Resolved<string>> (fl.alt (fl.never) (fl.resolve ('a')));
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expectType<fl.Resolved<number>> (fl.alt (fl.reject ('a')) (fl.resolve (42)));
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expectType<fl.Resolved<number>> (fl.alt (fl.resolve (42)) (fl.reject ('a')));
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expectType<fl.Resolved<number>> (fl.alt (fl.resolve (42)) (fl.resolve (42)));
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expectType<fl.Rejected<number>> (fl.alt (fl.reject (42)) (fl.reject (42)));
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expectType<fl.Rejected<string>> (fl.alt (fl.reject ('a')) (fl.reject (42)));
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expectType<fl.Uncertain<string, number>> (fl.alt (fsn) (fsn));
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expectType<fl.Resolved<number>> (fl.alt (fl.resolve ('a')) (fl.resolve (42)));
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expectError (fl.alt (fsn) (fns));
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const x = fl.alt (fl.never) (fl.never)
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// Usage with pipe on Future instances (https://git.io/JLx3F).
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expectType<fl.Never> ((fl.never) .pipe (fl.alt (fl.never)));
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expectType<fl.Never> ((fl.never) .pipe (fl.alt (fl.reject ('a'))));
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expectType<fl.Never> ((fl.never) .pipe (fl.alt (fl.resolve ('a'))));
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expectType<fl.Never> ((fl.reject ('a')) .pipe (fl.alt (fl.never)));
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expectType<fl.Resolved<string>> ((fl.resolve ('a')) .pipe (fl.alt (fl.never)));
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expectType<fl.Resolved<number>> ((fl.resolve (42)) .pipe (fl.alt (fl.reject ('a'))));
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expectType<fl.Resolved<number>> ((fl.reject ('a')) .pipe (fl.alt (fl.resolve (42))));
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expectType<fl.Resolved<number>> ((fl.resolve (42)) .pipe (fl.alt (fl.resolve (42))));
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expectType<fl.Rejected<number>> ((fl.reject (42)) .pipe (fl.alt (fl.reject (42))));
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expectType<fl.Rejected<string>> ((fl.reject (42)) .pipe (fl.alt (fl.reject ('a'))));
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expectType<fl.Uncertain<string, number>> ((fsn) .pipe (fl.alt (fsn)));
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expectType<fl.Resolved<number>> ((fl.resolve (42)) .pipe (fl.alt (fl.resolve ('a'))));
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expectError ((fns) .pipe (fl.alt (fsn)));
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const csn: fl.ConcurrentFutureInstance<string, number> = fl.Par (fl.resolve (42));
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const cns: fl.ConcurrentFutureInstance<number, string> = fl.Par (fl.resolve ('a'));
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// Standard usage on ConcurrentFuture instances.
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expectType<fl.ConcurrentNever> (fl.alt (fl.Par (fl.never)) (fl.Par (fl.never)));
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expectType<fl.ConcurrentRejected<string>> (fl.alt (fl.Par (fl.reject ('a'))) (fl.Par (fl.never)));
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expectType<fl.ConcurrentResolved<string>> (fl.alt (fl.Par (fl.resolve ('a'))) (fl.Par (fl.never)));
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expectType<fl.ConcurrentRejected<string>> (fl.alt (fl.Par (fl.never)) (fl.Par (fl.reject ('a'))));
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expectType<fl.ConcurrentResolved<string>> (fl.alt (fl.Par (fl.never)) (fl.Par (fl.resolve ('a'))));
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expectType<fl.ConcurrentFutureInstance<string, number>> (fl.alt (fl.Par (fl.reject ('a'))) (fl.Par (fl.resolve (42))));
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expectType<fl.ConcurrentFutureInstance<string, number>> (fl.alt (fl.Par (fl.resolve (42))) (fl.Par (fl.reject ('a'))));
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expectType<fl.ConcurrentResolved<number>> (fl.alt (fl.Par (fl.resolve (42))) (fl.Par (fl.resolve (42))));
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expectType<fl.ConcurrentRejected<number>> (fl.alt (fl.Par (fl.reject (42))) (fl.Par (fl.reject (42))));
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expectType<fl.ConcurrentUncertain<string, number>> (fl.alt (csn) (csn));
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expectError (fl.alt (fl.Par (fl.resolve ('a'))) (fl.Par (fl.resolve (42))));
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expectError (fl.alt (fl.Par (fl.reject ('a'))) (fl.Par (fl.reject (42))));
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expectError (fl.alt (csn) (cns));

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