"use strict";

const assert = require('assert');

const isFunction = require("../../src/deps/is/function");

const pipe = require("../../src/deps/fp/pipeTwo");

const pipeAll = require("../../src/deps/fp/pipe");

describe('pipe', function () {
  it('is in correct order', function () {
    function x(val) {
      return val + 'x';
    }

    function y(val) {
      return val + 'y';
    }

    function z(val) {
      return val + 'z';
    }

    expect(pipeAll(x, y, z)('w')).toBe('wxyz');
  });
  it('is a variadic function', function () {
    expect(isFunction(pipe)).toBe(true);
    expect(isFunction(pipeAll)).toBe(true); // is a smaller version just 2 args
    // expect(pipe.length).toBe(0)
  });
  it('passes context to functions', function () {
    function x(val) {
      return this.x * val;
    }

    function y(val) {
      return this.y * val;
    }

    function z(val) {
      return this.z * val;
    }

    var context = {
      a: pipe(pipe(x, y), z),
      x: 4,
      y: 2,
      z: 1
    };
    expect(context.a(5)).toBe(40);
  });
  it.skip('throws if given no arguments', function () {
    assert.throws(function () {
      pipe();
    }, function (err) {
      return err.constructor === Error && err.message === 'pipe requires at least one argument';
    });
  });
  it('can be applied to one argument, (with 2 fns)', function () {
    var f = function f(a, b, c) {
      return [a, b, c];
    };

    var g = pipe(f, x => x); // expect(g.length).toEqual(3)

    expect(g(1, 2, 3)).toEqual([1, 2, 3]);
  });
});