import assert from 'assert';
import lodashStable from 'lodash';
import { _, args, LARGE_ARRAY_SIZE, stubNaN } from './utils.js';

describe('intersection methods', function() {
  lodashStable.each(['intersection', 'intersectionBy', 'intersectionWith'], function(methodName) {
    var func = _[methodName];

    it('`_.' + methodName + '` should return the intersection of two arrays', function() {
      var actual = func([2, 1], [2, 3]);
      assert.deepStrictEqual(actual, [2]);
    });

    it('`_.' + methodName + '` should return the intersection of multiple arrays', function() {
      var actual = func([2, 1, 2, 3], [3, 4], [3, 2]);
      assert.deepStrictEqual(actual, [3]);
    });

    it('`_.' + methodName + '` should return an array of unique values', function() {
      var actual = func([1, 1, 3, 2, 2], [5, 2, 2, 1, 4], [2, 1, 1]);
      assert.deepStrictEqual(actual, [1, 2]);
    });

    it('`_.' + methodName + '` should work with a single array', function() {
      var actual = func([1, 1, 3, 2, 2]);
      assert.deepStrictEqual(actual, [1, 3, 2]);
    });

    it('`_.' + methodName + '` should work with `arguments` objects', function() {
      var array = [0, 1, null, 3],
          expected = [1, 3];

      assert.deepStrictEqual(func(array, args), expected);
      assert.deepStrictEqual(func(args, array), expected);
    });

    it('`_.' + methodName + '` should treat `-0` as `0`', function() {
      var values = [-0, 0],
          expected = lodashStable.map(values, lodashStable.constant(['0']));

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

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

    it('`_.' + methodName + '` should match `NaN`', function() {
      var actual = func([1, NaN, 3], [NaN, 5, NaN]);
      assert.deepStrictEqual(actual, [NaN]);
    });

    it('`_.' + methodName + '` should work with large arrays of `-0` as `0`', function() {
      var values = [-0, 0],
          expected = lodashStable.map(values, lodashStable.constant(['0']));

      var actual = lodashStable.map(values, function(value) {
        var largeArray = lodashStable.times(LARGE_ARRAY_SIZE, lodashStable.constant(value));
        return lodashStable.map(func(values, largeArray), lodashStable.toString);
      });

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

    it('`_.' + methodName + '` should work with large arrays of `NaN`', function() {
      var largeArray = lodashStable.times(LARGE_ARRAY_SIZE, stubNaN);
      assert.deepStrictEqual(func([1, NaN, 3], largeArray), [NaN]);
    });

    it('`_.' + methodName + '` should work with large arrays of objects', function() {
      var object = {},
          largeArray = lodashStable.times(LARGE_ARRAY_SIZE, lodashStable.constant(object));

      assert.deepStrictEqual(func([object], largeArray), [object]);
      assert.deepStrictEqual(func(lodashStable.range(LARGE_ARRAY_SIZE), [1]), [1]);
    });

    it('`_.' + methodName + '` should treat values that are not arrays or `arguments` objects as empty', function() {
      var array = [0, 1, null, 3];
      assert.deepStrictEqual(func(array, 3, { '0': 1 }, null), []);
      assert.deepStrictEqual(func(null, array, null, [2, 3]), []);
      assert.deepStrictEqual(func(array, null, args, null), []);
    });

    it('`_.' + methodName + '` should return a wrapped value when chaining', function() {
      var wrapped = _([1, 3, 2])[methodName]([5, 2, 1, 4]);
      assert.ok(wrapped instanceof _);
      assert.deepEqual(wrapped.value(), [1, 2]);
    });
  });
});