93 lines
3 KiB
JavaScript
93 lines
3 KiB
JavaScript
import { isArray } from '@ember/array';
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import { module, test } from 'qunit';
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import RollingArray from 'nomad-ui/utils/classes/rolling-array';
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module('Unit | Util | RollingArray', function() {
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test('has a maxLength property that gets set in the constructor', function(assert) {
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const array = RollingArray(10, 'a', 'b', 'c');
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assert.equal(array.maxLength, 10, 'maxLength is set in the constructor');
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assert.deepEqual(
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array,
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['a', 'b', 'c'],
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'additional arguments to the constructor become elements'
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);
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});
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test('push works like Array#push', function(assert) {
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const array = RollingArray(10);
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const pushReturn = array.push('a');
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assert.equal(
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pushReturn,
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array.length,
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'the return value from push is equal to the return value of Array#push'
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);
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assert.equal(array[0], 'a', 'the arguments passed to push are appended to the array');
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array.push('b', 'c', 'd');
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assert.deepEqual(
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array,
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['a', 'b', 'c', 'd'],
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'the elements already in the array are left in tact and new elements are appended'
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);
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});
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test('when pushing past maxLength, items are removed from the head of the array', function(assert) {
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const array = RollingArray(3);
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const pushReturn = array.push(1, 2, 3, 4);
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assert.deepEqual(
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array,
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[2, 3, 4],
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'The first argument to push is not in the array, but the following three are'
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);
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assert.equal(
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pushReturn,
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array.length,
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'The return value of push is still the array length despite more arguments than possible were provided to push'
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);
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});
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test('when splicing past maxLength, items are removed from the head of the array', function(assert) {
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const array = RollingArray(3, 'a', 'b', 'c');
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array.splice(1, 0, 'z');
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assert.deepEqual(
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array,
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['z', 'b', 'c'],
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'The new element is inserted as the second element in the array and the first element is removed due to maxLength restrictions'
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);
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array.splice(0, 0, 'pickme');
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assert.deepEqual(
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array,
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['z', 'b', 'c'],
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'The new element never makes it into the array since it was added at the head of the array and immediately removed'
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);
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array.splice(0, 1, 'pickme');
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assert.deepEqual(
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array,
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['pickme', 'b', 'c'],
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'The new element makes it into the array since the previous element at the head of the array is first removed due to the second argument to splice'
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);
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});
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test('unshift throws instead of prepending elements', function(assert) {
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const array = RollingArray(5);
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assert.throws(
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() => {
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array.unshift(1);
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},
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/Cannot unshift/,
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'unshift is not supported, but is not undefined'
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);
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});
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test('RollingArray is an instance of Array', function(assert) {
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const array = RollingArray(5);
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assert.ok(array.constructor === Array, 'The constructor is Array');
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assert.ok(array instanceof Array, 'The instanceof check is true');
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assert.ok(isArray(array), 'The ember isArray helper works');
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});
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});
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