balazsbotond/eslinq

"use strict";

import from from "../src/eslinq";
import { identity, even, constantFalse, constantTrue } from "./helpers";

describe(".any", () => {

    it("throws if it is called with a non-function argument", () => {
        expect(() => from([1]).any(0)).toThrowError("`matches` should be a function");
    });

    it("returns false when given an empty iterable and a constant true condition", () => {
        expect(from([]).any(constantTrue)).toBe(false);
    });

    it("returns false when given an empty iterable and a constant false condition", () => {
        expect(from([]).any(constantFalse)).toBe(false);
    });

    it("returns true when given a one-element iterable and a constant true condition", () => {
        const original = [1],
            expected = true,
            actual = from(original).any(constantTrue);
        expect(actual).toEqual(expected);
    });

    it("returns false when given a one-element iterable and a constant false condition", () => {
        const original = [1],
            expected = false,
            actual = from(original).any(constantFalse);
        expect(actual).toEqual(expected);
    });

    it("returns false if no elements match", () => {
        const original = [1, 3, 5],
            expected = false,
            actual = from(original).any(even);
        expect(actual).toEqual(expected);
    });

    it("returns true if the first element matches", () => {
        expect(from([2, 3, 5]).any(even)).toBe(true);
    });

    it("returns true if the last element matches", () => {
        expect(from([1, 3, 4]).any(even)).toBe(true);
    });

    it("returns true if all elements match", () => {
        expect(from([2, 4, 6]).any(even)).toBe(true);
    });

    it("works if the condition returns non-boolean truthy values", () => {
        const cases = [1, "1"];
        for (let c of cases)
            expect(from([c]).any(identity)).toBe(true);
    });

    it("works if the condition returns non-boolean falsy values", () => {
        const original = [0, undefined, NaN, ""];
        expect(from(original).any(identity)).toBe(false);
    });

});