lodash/test/sortedIndexBy-methods.js

import assert from 'assert';
import lodashStable from 'lodash';
import { _, slice, MAX_ARRAY_LENGTH, MAX_ARRAY_INDEX } from './utils.js';

describe('sortedIndexBy methods', function() {
  lodashStable.each(['sortedIndexBy', 'sortedLastIndexBy'], function(methodName) {
    var func = _[methodName],
        isSortedIndexBy = methodName == 'sortedIndexBy';

    it('`_.' + methodName + '` should provide correct `iteratee` arguments', function() {
      var args;

      func([30, 50], 40, function() {
        args || (args = slice.call(arguments));
      });

      assert.deepStrictEqual(args, [40]);
    });

    it('`_.' + methodName + '` should work with `_.property` shorthands', function() {
      var objects = [{ 'x': 30 }, { 'x': 50 }],
          actual = func(objects, { 'x': 40 }, 'x');

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

    it('`_.' + methodName + '` should avoid calling iteratee when length is 0', function() {
      var objects = [],
          actual = func(objects, { 'x': 50 }, assert.fail);

      assert.strictEqual(actual, 0);
    });

    it('`_.' + methodName + '` should support arrays larger than `MAX_ARRAY_LENGTH / 2`', function() {
      lodashStable.each([Math.ceil(MAX_ARRAY_LENGTH / 2), MAX_ARRAY_LENGTH], function(length) {
        var array = [],
            values = [MAX_ARRAY_LENGTH, NaN, undefined];

        array.length = length;

        lodashStable.each(values, function(value) {
          var steps = 0;

          var actual = func(array, value, function(value) {
            steps++;
            return value;
          });

          var expected = (isSortedIndexBy ? !lodashStable.isNaN(value) : lodashStable.isFinite(value))
            ? 0
            : Math.min(length, MAX_ARRAY_INDEX);

          assert.ok(steps == 32 || steps == 33);
          assert.strictEqual(actual, expected);
        });
      });
    });
  });
});