has-methods.js

import assert from 'assert';
import lodashStable from 'lodash';
import { _, toArgs, stubTrue, args, symbol, defineProperty, stubFalse } from './utils.js';

describe('has methods', function() {
  lodashStable.each(['has', 'hasIn'], function(methodName) {
    var func = _[methodName],
        isHas = methodName == 'has',
        sparseArgs = toArgs([1]),
        sparseArray = Array(1),
        sparseString = Object('a');

    delete sparseArgs[0];
    delete sparseString[0];

    it('`_.' + methodName + '` should check for own properties', function() {
      var object = { 'a': 1 };

      lodashStable.each(['a', ['a']], function(path) {
        assert.strictEqual(func(object, path), true);
      });
    });

    it('`_.' + methodName + '` should not use the `hasOwnProperty` method of `object`', function() {
      var object = { 'hasOwnProperty': null, 'a': 1 };
      assert.strictEqual(func(object, 'a'), true);
    });

    it('`_.' + methodName + '` should support deep paths', function() {
      var object = { 'a': { 'b': 2 } };

      lodashStable.each(['a.b', ['a', 'b']], function(path) {
        assert.strictEqual(func(object, path), true);
      });

      lodashStable.each(['a.a', ['a', 'a']], function(path) {
        assert.strictEqual(func(object, path), false);
      });
    });

    it('`_.' + methodName + '` should coerce `path` to a string', function() {
      function fn() {}
      fn.toString = lodashStable.constant('fn');

      var object = { 'null': 1 , 'undefined': 2, 'fn': 3, '[object Object]': 4 },
          paths = [null, undefined, fn, {}],
          expected = lodashStable.map(paths, stubTrue);

      lodashStable.times(2, function(index) {
        var actual = lodashStable.map(paths, function(path) {
          return func(object, index ? [path] : path);
        });

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

    it('`_.' + methodName + '` should work with `arguments` objects', function() {
      assert.strictEqual(func(args, 1), true);
    });

    it('`_.' + methodName + '` should work with a non-string `path`', function() {
      var array = [1, 2, 3];

      lodashStable.each([1, [1]], function(path) {
        assert.strictEqual(func(array, path), true);
      });
    });

    it('`_.' + methodName + '` should preserve the sign of `0`', function() {
      var object = { '-0': 'a', '0': 'b' },
          props = [-0, Object(-0), 0, Object(0)],
          expected = lodashStable.map(props, stubTrue);

      var actual = lodashStable.map(props, function(key) {
        return func(object, key);
      });

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

    it('`_.' + methodName + '` should work with a symbol `path`', function() {
      function Foo() {}

      if (Symbol) {
        Foo.prototype[symbol] = 1;

        var symbol2 = Symbol('b');
        defineProperty(Foo.prototype, symbol2, {
          'configurable': true,
          'enumerable': false,
          'writable': true,
          'value': 2
        });

        var object = isHas ? Foo.prototype : new Foo;
        assert.strictEqual(func(object, symbol), true);
        assert.strictEqual(func(object, symbol2), true);
      }
    });

    it('`_.' + methodName + '` should check for a key over a path', function() {
      var object = { 'a.b': 1 };

      lodashStable.each(['a.b', ['a.b']], function(path) {
        assert.strictEqual(func(object, path), true);
      });
    });

    it('`_.' + methodName + '` should return `true` for indexes of sparse values', function() {
      var values = [sparseArgs, sparseArray, sparseString],
          expected = lodashStable.map(values, stubTrue);

      var actual = lodashStable.map(values, function(value) {
        return func(value, 0);
      });

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

    it('`_.' + methodName + '` should return `true` for indexes of sparse values with deep paths', function() {
      var values = [sparseArgs, sparseArray, sparseString],
          expected = lodashStable.map(values, lodashStable.constant([true, true]));

      var actual = lodashStable.map(values, function(value) {
        return lodashStable.map(['a[0]', ['a', '0']], function(path) {
          return func({ 'a': value }, path);
        });
      });

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

    it('`_.' + methodName + '` should return `' + (isHas ? 'false' : 'true') + '` for inherited properties', function() {
      function Foo() {}
      Foo.prototype.a = 1;

      lodashStable.each(['a', ['a']], function(path) {
        assert.strictEqual(func(new Foo, path), !isHas);
      });
    });

    it('`_.' + methodName + '` should return `' + (isHas ? 'false' : 'true') + '` for nested inherited properties', function() {
      function Foo() {}
      Foo.prototype.a = { 'b': 1 };

      lodashStable.each(['a.b', ['a', 'b']], function(path) {
        assert.strictEqual(func(new Foo, path), !isHas);
      });
    });

    it('`_.' + methodName + '` should return `false` when `object` is nullish', function() {
      var values = [null, undefined],
          expected = lodashStable.map(values, stubFalse);

      lodashStable.each(['constructor', ['constructor']], function(path) {
        var actual = lodashStable.map(values, function(value) {
          return func(value, path);
        });

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

    it('`_.' + methodName + '` should return `false` for deep paths when `object` is nullish', function() {
      var values = [null, undefined],
          expected = lodashStable.map(values, stubFalse);

      lodashStable.each(['constructor.prototype.valueOf', ['constructor', 'prototype', 'valueOf']], function(path) {
        var actual = lodashStable.map(values, function(value) {
          return func(value, path);
        });

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

    it('`_.' + methodName + '` should return `false` for nullish values of nested objects', function() {
      var values = [, null, undefined],
          expected = lodashStable.map(values, stubFalse);

      lodashStable.each(['a.b', ['a', 'b']], function(path) {
        var actual = lodashStable.map(values, function(value, index) {
          var object = index ? { 'a': value } : {};
          return func(object, path);
        });

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

    it('`_.' + methodName + '` should return `false` over sparse values of deep paths', function() {
      var values = [sparseArgs, sparseArray, sparseString],
          expected = lodashStable.map(values, lodashStable.constant([false, false]));

      var actual = lodashStable.map(values, function(value) {
        return lodashStable.map(['a[0].b', ['a', '0', 'b']], function(path) {
          return func({ 'a': value }, path);
        });
      });

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