expect-more-jasmine

Write Beautiful Specs with Custom Matchers for Jasmine

Table of Contents

• Overview
• 🌩 Installation
• 🕹 Configuration
• 🔬 Matchers
• 🙋🏽‍♂️ Getting Help
• 👀 Other Projects
• 🤓 Author

Overview

expect-more-jasmine is a huge library of test matchers for a range of common use-cases, to make tests easier to read and produce relevant and useful messages when they fail.

Avoid vague messages such as "expected false to be true" in favour of useful cues like "expected 3 to be even number", and avoid implementation noise such as expect(paws.length % 2 === 0).toEqual(true) in favour of simply stating that you expect(paws.length).toBeEvenNumber().

🌩 Installation

npm install expect-more-jasmine --save-dev

🕹 Configuration

import 'expect-more-jasmine' or require('expect-more-jasmine') at the top your test file.

🔬 Matchers

1describe('expect-more-jasmine', () => {
2  it('makes your tests and output easier to read', () => {
3    expect(new Date('2020-01-01')).toBeAfter(new Date('2019-12-31'));
4    expect([12, 0, 14, 'Ivo']).toBeArrayIncludingAllOf(['Ivo', 14]);
5    expect([12, 0, 14, 'Ginola']).toBeArrayIncludingAnyOf(['Ginola', 3]);
6    expect([5, 10, 1]).toBeArrayIncludingOnly([1, 5, 10]);
7    expect([true, false, new Boolean(true)]).toBeArrayOfBooleans();
8    expect([12, 0, 14]).toBeArrayOfNumbers();
9    expect([{}, new Object()]).toBeArrayOfObjects();
10    expect(['i', 'contain', 4, 'items']).toBeArrayOfSize(4);
11    expect(['we', 'are', 'all', 'strings']).toBeArrayOfStrings();
12    expect([2, true, 'string']).toBeArray();
13    expect(async () => {
14      await fetch('...');
15    }).toBeAsyncFunction();
16    expect(new Date('2019-12-31')).toBeBefore(new Date('2020-01-01'));
17    expect(false).toBeBoolean();
18    expect('100').toBeCalculable();
19    expect(new Date('2019-12-11')).toBeDateBetween(new Date('2019-12-10'), new Date('2019-12-12'));
20    expect(new Date('2021-08-29')).toBeDateInMonth(7);
21    expect(new Date('2021-08-29')).toBeDateInYear(2021);
22    expect(new Date('2021-08-29')).toBeDateOnDayOfMonth(29);
23    expect(new Date('2021-08-29')).toBeDateOnDayOfWeek(0);
24    expect(new Date('2019-12-31')).toBeDateOnOrAfter(new Date('2019-12-15'));
25    expect(new Date('2019-12-15')).toBeDateOnOrBefore(new Date('2019-12-31'));
26    expect(new Date('2019-12-31')).toBeDate();
27    expect(12.55).toBeDecimalNumber();
28    expect(12).toBeDivisibleBy(2);
29    expect([]).toBeEmptyArray();
30    expect({}).toBeEmptyObject();
31    expect('').toBeEmptyString();
32    expect(2).toBeEvenNumber();
33    expect(() => 'i am a function').toBeFunction();
34    expect(function* gen() {
35      yield 'i am a generator';
36    }).toBeGeneratorFunction();
37    expect('1999-12-31T23:59:59').toBeIso8601();
38    expect('{"i":"am valid JSON"}').toBeJsonString();
39    expect(['i', 'have', 3]).toBeLongerThan([2, 'items']);
40    expect(-18).toBeNegativeNumber();
41    expect(undefined).toBeNil();
42    expect(['i', 'am not empty']).toBeNonEmptyArray();
43    expect({ i: 'am not empty' }).toBeNonEmptyObject();
44    expect('i am not empty').toBeNonEmptyString();
45    expect(8).toBeNumber();
46    expect({}).toBeObject();
47    expect(5).toBeOddNumber();
48    expect(5).toBePositiveNumber();
49    expect(new RegExp('i am a regular expression')).toBeRegExp();
50    expect(['i also have', '2 items']).toBeSameLengthAs(['i have', '2 items']);
51    expect(['i have one item']).toBeShorterThan(['i', 'have', 4, 'items']);
52    expect('i am a string').toBeString();
53    expect(new Date('2020-01-01')).toBeValidDate();
54    expect('i am visible').toBeVisibleString();
55    expect({}).toBeWalkable();
56    expect(' ').toBeWhitespace();
57    expect(8).toBeWholeNumber();
58    expect(7).toBeWithinRange(0, 10);
59    expect('JavaScript').toEndWith('Script');
60    expect({ child: { grandchild: [12, 0, 14, 'Ivo'] } }).toHaveArrayIncludingAllOf('child.grandchild', ['Ivo', 14]);
61    expect({ child: { grandchild: [12, 0, 14, 'Ginola'] } }).toHaveArrayIncludingAnyOf('child.grandchild', ['Ginola', 3]);
62    expect({ child: { grandchild: [5, 10, 1] } }).toHaveArrayIncludingOnly('child.grandchild', [1, 5, 10]);
63    expect({ child: { grandchild: [true, false, new Boolean(true)] } }).toHaveArrayOfBooleans('child.grandchild');
64    expect({ child: { grandchild: [12, 0, 14] } }).toHaveArrayOfNumbers('child.grandchild');
65    expect({ child: { grandchild: [{}, new Object()] } }).toHaveArrayOfObjects('child.grandchild');
66    expect({ child: { grandchild: ['i', 'contain', 4, 'items'] } }).toHaveArrayOfSize('child.grandchild', 4);
67    expect({ child: { grandchild: ['we', 'are', 'all', 'strings'] } }).toHaveArrayOfStrings('child.grandchild');
68    expect({ child: { grandchild: [2, true, 'string'] } }).toHaveArray('child.grandchild');
69    expect({
70      child: {
71        grandchild: async () => {
72          await fetch('...');
73        },
74      },
75    }).toHaveAsyncFunction('child.grandchild');
76    expect({ child: { grandchild: false } }).toHaveBoolean('child.grandchild');
77    expect({ child: { grandchild: '100' } }).toHaveCalculable('child.grandchild');
78    expect({ child: { grandchild: new Date('2020-01-01') } }).toHaveDateAfter('child.grandchild', new Date('2019-12-31'));
79    expect({ child: { grandchild: new Date('2019-12-31') } }).toHaveDateBefore('child.grandchild', new Date('2020-01-01'));
80    expect({ child: { grandchild: new Date('2019-12-11') } }).toHaveDateBetween('child.grandchild', new Date('2019-12-10'), new Date('2019-12-12'));
81    expect({ child: { grandchild: new Date('2021-08-29') } }).toHaveDateInMonth('child.grandchild', 7);
82    expect({ child: { grandchild: new Date('2021-08-29') } }).toHaveDateInYear('child.grandchild', 2021);
83    expect({ child: { grandchild: new Date('2021-08-29') } }).toHaveDateOnDayOfMonth('child.grandchild', 29);
84    expect({ child: { grandchild: new Date('2021-08-29') } }).toHaveDateOnDayOfWeek('child.grandchild', 0);
85    expect({ child: { grandchild: new Date('2019-12-31') } }).toHaveDateOnOrAfter('child.grandchild', new Date('2019-12-15'));
86    expect({ child: { grandchild: new Date('2019-12-15') } }).toHaveDateOnOrBefore('child.grandchild', new Date('2019-12-31'));
87    expect({ child: { grandchild: new Date('2019-12-31') } }).toHaveDate('child.grandchild');
88    expect({ child: { grandchild: 12.55 } }).toHaveDecimalNumber('child.grandchild');
89    expect({ child: { grandchild: 12 } }).toHaveDivisibleBy('child.grandchild', 2);
90    expect({ child: { grandchild: [] } }).toHaveEmptyArray('child.grandchild');
91    expect({ child: { grandchild: {} } }).toHaveEmptyObject('child.grandchild');
92    expect({ child: { grandchild: '' } }).toHaveEmptyString('child.grandchild');
93    expect({ child: { grandchild: 'JavaScript' } }).toHaveEndingWith('child.grandchild', 'Script');
94    expect({ child: { grandchild: 2 } }).toHaveEvenNumber('child.grandchild');
95    expect({ child: { grandchild: false } }).toHaveFalse('child.grandchild');
96    expect({
97      child: {
98        grandchild: function* gen() {
99          yield 'i am a generator';
100        },
101      },
102    }).toHaveGeneratorFunction('child.grandchild');
103    expect({ child: { grandchild: 10 } }).toHaveGreaterThanOrEqualTo('child.grandchild', 5);
104    expect({ child: { grandchild: '1999-12-31T23:59:59' } }).toHaveIso8601('child.grandchild');
105    expect({ child: { grandchild: '{"i":"am valid JSON"}' } }).toHaveJsonString('child.grandchild');
106    expect({ child: { grandchild: 8 } }).toHaveLessThanOrEqualTo('child.grandchild', 12);
107    expect({ child: { grandchild: ['i', 'have', 3] } }).toHaveLongerThan('child.grandchild', [2, 'items']);
108    expect({ child: { grandchild: () => 'i am a function' } }).toHaveMethod('child.grandchild');
109    expect({ child: { grandchild: -18 } }).toHaveNegativeNumber('child.grandchild');
110    expect({ child: { grandchild: undefined } }).toHaveNil('child.grandchild');
111    expect({ child: { grandchild: ['i', 'am not empty'] } }).toHaveNonEmptyArray('child.grandchild');
112    expect({ child: { grandchild: { i: 'am not empty' } } }).toHaveNonEmptyObject('child.grandchild');
113    expect({ child: { grandchild: 'i am not empty' } }).toHaveNonEmptyString('child.grandchild');
114    expect({ child: { grandchild: null } }).toHaveNull('child.grandchild');
115    expect({ child: { grandchild: 4.8 } }).toHaveNumberNear('child.grandchild', 5, 0.5);
116    expect({ child: { grandchild: 7 } }).toHaveNumberWithinRange('child.grandchild', 0, 10);
117    expect({ child: { grandchild: 8 } }).toHaveNumber('child.grandchild');
118    expect({ child: { grandchild: {} } }).toHaveObject('child.grandchild');
119    expect({ child: { grandchild: 5 } }).toHaveOddNumber('child.grandchild');
120    expect({ child: { grandchild: 5 } }).toHavePositiveNumber('child.grandchild');
121    expect({ child: { grandchild: new RegExp('i am a regular expression') } }).toHaveRegExp('child.grandchild');
122    expect({ child: { grandchild: ['i also have', '2 items'] } }).toHaveSameLengthAs('child.grandchild', ['i have', '2 items']);
123    expect({ child: { grandchild: ['i have one item'] } }).toHaveShorterThan('child.grandchild', ['i', 'have', 4, 'items']);
124    expect({ child: { grandchild: 'JavaScript' } }).toHaveStartingWith('child.grandchild', 'Java');
125    expect({ child: { grandchild: 'i am a string' } }).toHaveString('child.grandchild');
126    expect({ child: { grandchild: true } }).toHaveTrue('child.grandchild');
127    expect({ child: { grandchild: undefined } }).toHaveUndefined('child.grandchild');
128    expect({ child: { grandchild: new Date('2020-01-01') } }).toHaveValidDate('child.grandchild');
129    expect({ child: { grandchild: 'i am visible' } }).toHaveVisibleString('child.grandchild');
130    expect({ child: { grandchild: {} } }).toHaveWalkable('child.grandchild');
131    expect({ child: { grandchild: ' ' } }).toHaveWhitespace('child.grandchild');
132    expect({ child: { grandchild: 8 } }).toHaveWholeNumber('child.grandchild');
133    expect('JavaScript').toStartWith('Java');
134  });
135});

🙋🏽‍♂️ Getting Help

Get help with issues by creating a Bug Report or discuss ideas by opening a Feature Request.

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🤓 Author

I'm Jamie Mason from Leeds in England, I began Web Design and Development in 1999 and have been Contracting and offering Consultancy as Fold Left Ltd since 2012. Who I've worked with includes Sky Sports, Sky Bet, Sky Poker, The Premier League, William Hill, Shell, Betfair, and Football Clubs including Leeds United, Spurs, West Ham, Arsenal, and more.