lodash/test/methods-using-createWrapper.js

import assert from 'assert';
import lodashStable from 'lodash';
import { slice, _, push, HOT_COUNT } from './utils.js';
import bind from '../bind.js';
import bindKey from '../bindKey.js';
import partial from '../partial.js';
import partialRight from '../partialRight.js';
import last from '../last.js';

describe('methods using `createWrapper`', function() {
  function fn() {
    return slice.call(arguments);
  }

  var ph1 = bind.placeholder,
      ph2 = bindKey.placeholder,
      ph3 = partial.placeholder,
      ph4 = partialRight.placeholder;

  it('should work with combinations of partial functions', function() {
    var a = partial(fn),
        b = partialRight(a, 3),
        c = partial(b, 1);

    assert.deepStrictEqual(c(2), [1, 2, 3]);
  });

  it('should work with combinations of bound and partial functions', function() {
    var fn = function() {
      var result = [this.a];
      push.apply(result, arguments);
      return result;
    };

    var expected = [1, 2, 3, 4],
        object = { 'a': 1, 'fn': fn };

    var a = bindKey(object, 'fn'),
        b = partialRight(a, 4),
        c = partial(b, 2);

    assert.deepStrictEqual(c(3), expected);

    a = bind(fn, object);
    b = partialRight(a, 4);
    c = partial(b, 2);

    assert.deepStrictEqual(c(3), expected);

    a = partial(fn, 2);
    b = bind(a, object);
    c = partialRight(b, 4);

    assert.deepStrictEqual(c(3), expected);
  });

  it('should ensure `new combo` is an instance of `func`', function() {
    function Foo(a, b, c) {
      return b === 0 && object;
    }

    var combo = partial(partialRight(Foo, 3), 1),
        object = {};

    assert.ok(new combo(2) instanceof Foo);
    assert.strictEqual(new combo(0), object);
  });

  it('should work with combinations of functions with placeholders', function() {
    var expected = [1, 2, 3, 4, 5, 6],
        object = { 'fn': fn };

    var a = bindKey(object, 'fn', ph2, 2),
        b = partialRight(a, ph4, 6),
        c = partial(b, 1, ph3, 4);

    assert.deepStrictEqual(c(3, 5), expected);

    a = bind(fn, object, ph1, 2);
    b = partialRight(a, ph4, 6);
    c = partial(b, 1, ph3, 4);

    assert.deepStrictEqual(c(3, 5), expected);

    a = partial(fn, ph3, 2);
    b = bind(a, object, 1, ph1, 4);
    c = partialRight(b, ph4, 6);

    assert.deepStrictEqual(c(3, 5), expected);
  });

  it('should work with combinations of functions with overlapping placeholders', function() {
    var expected = [1, 2, 3, 4],
        object = { 'fn': fn };

    var a = bindKey(object, 'fn', ph2, 2),
        b = partialRight(a, ph4, 4),
        c = partial(b, ph3, 3);

    assert.deepStrictEqual(c(1), expected);

    a = bind(fn, object, ph1, 2);
    b = partialRight(a, ph4, 4);
    c = partial(b, ph3, 3);

    assert.deepStrictEqual(c(1), expected);

    a = partial(fn, ph3, 2);
    b = bind(a, object, ph1, 3);
    c = partialRight(b, ph4, 4);

    assert.deepStrictEqual(c(1), expected);
  });

  it('should work with recursively bound functions', function() {
    var fn = function() {
      return this.a;
    };

    var a = bind(fn, { 'a': 1 }),
        b = bind(a,  { 'a': 2 }),
        c = bind(b,  { 'a': 3 });

    assert.strictEqual(c(), 1);
  });

  it('should work when hot', function() {
    lodashStable.times(2, function(index) {
      var fn = function() {
        var result = [this];
        push.apply(result, arguments);
        return result;
      };

      var object = {},
          bound1 = index ? bind(fn, object, 1) : bind(fn, object),
          expected = [object, 1, 2, 3];

      var actual = last(lodashStable.times(HOT_COUNT, function() {
        var bound2 = index ? bind(bound1, null, 2) : bind(bound1);
        return index ? bound2(3) : bound2(1, 2, 3);
      }));

      assert.deepStrictEqual(actual, expected);

      actual = last(lodashStable.times(HOT_COUNT, function() {
        var bound1 = index ? bind(fn, object, 1) : bind(fn, object),
            bound2 = index ? bind(bound1, null, 2) : bind(bound1);

        return index ? bound2(3) : bound2(1, 2, 3);
      }));

      assert.deepStrictEqual(actual, expected);
    });

    lodashStable.each(['curry', 'curryRight'], function(methodName, index) {
      var fn = function(a, b, c) { return [a, b, c]; },
          curried = _[methodName](fn),
          expected = index ? [3, 2, 1] :  [1, 2, 3];

      var actual = last(lodashStable.times(HOT_COUNT, function() {
        return curried(1)(2)(3);
      }));

      assert.deepStrictEqual(actual, expected);

      actual = last(lodashStable.times(HOT_COUNT, function() {
        var curried = _[methodName](fn);
        return curried(1)(2)(3);
      }));

      assert.deepStrictEqual(actual, expected);
    });

    lodashStable.each(['partial', 'partialRight'], function(methodName, index) {
      var func = _[methodName],
          fn = function() { return slice.call(arguments); },
          par1 = func(fn, 1),
          expected = index ? [3, 2, 1] : [1, 2, 3];

      var actual = last(lodashStable.times(HOT_COUNT, function() {
        var par2 = func(par1, 2);
        return par2(3);
      }));

      assert.deepStrictEqual(actual, expected);

      actual = last(lodashStable.times(HOT_COUNT, function() {
        var par1 = func(fn, 1),
            par2 = func(par1, 2);

        return par2(3);
      }));

      assert.deepStrictEqual(actual, expected);
    });
  });
});