Files
lodash/test/constant.js
Benjamin Tan d5ef31929a Add initial test files from lodash v4. (#4172)
* Install test dependencies.

* Add initial test files.

These files were created using a simplistic AST manipulator using `recast` to
preserve formatting. There's bound to be a huge chunk of errors, but this serves
as a good start. QUnit was replaced with Mocha, with ES2015 imports running via
`esm`.

As far as possible, QUnit-specific syntax has been replaced with Mocha's
`describe` and `it`, while the native Node.js `assert` module is used for
assertions. Files in the `test` directory ending in `.test.js` will be treated
as test files.

* Add initial passing files to test run.
2019-02-12 09:11:32 -08:00

41 lines
1.2 KiB
JavaScript

import assert from 'assert';
import lodashStable from 'lodash';
import { empties, _, falsey, stubTrue } from './utils.js';
describe('constant', function() {
it('should create a function that returns `value`', function() {
var object = { 'a': 1 },
values = Array(2).concat(empties, true, 1, 'a'),
constant = _.constant(object);
var results = lodashStable.map(values, function(value, index) {
if (index < 2) {
return index ? constant.call({}) : constant();
}
return constant(value);
});
assert.ok(lodashStable.every(results, function(result) {
return result === object;
}));
});
it('should work with falsey values', function() {
var expected = lodashStable.map(falsey, stubTrue);
var actual = lodashStable.map(falsey, function(value, index) {
var constant = index ? _.constant(value) : _.constant(),
result = constant();
return (result === value) || (result !== result && value !== value);
});
assert.deepStrictEqual(actual, expected);
});
it('should return a wrapped value when chaining', function() {
var wrapped = _(true).constant();
assert.ok(wrapped instanceof _);
});
});