card-validator/src/__tests__/lib/is-array.ts

A library for validating credit card fields

import { isArray } from "../../lib/is-array";

describe("isArray", () => {
  it("returns true for arrays", () => {
    expect(isArray([])).toBe(true);
    expect(isArray([1, 2])).toBe(true);
    expect(isArray([null])).toBe(true);
  });

  it("returns false for non-arrays", () => {
    expect(isArray()).toBe(false);
    expect(isArray(undefined)).toBe(false); // eslint-disable-line no-undefined
    expect(isArray(null)).toBe(false);
    expect(isArray(true)).toBe(false);
    expect(isArray(false)).toBe(false);
    expect(isArray(0)).toBe(false);
    expect(isArray(1)).toBe(false);
    expect(isArray("arr")).toBe(false);
    expect(isArray({})).toBe(false);
    expect(isArray({ length: 2 })).toBe(false);
  });
});