Jasmine-Matchers

Jasmine-Matchers

Write Beautiful Specs with Custom Matchers

Table of Contents

• Overview
• 🌩 Installation
• 📝 API
• 🕹 Usage
• 🌍 Browser Support
• 🙋🏽‍♂️ Getting Help
• 👀 Other Projects
• 🤓 Author

Overview

What

A huge library of test matchers for a range of common use-cases, compatible with all versions of Jasmine and Jest.

Why

Custom Matchers make tests easier to read and produce relevant and useful messages when they fail.

How

By avoiding vague messages such as “expected false to be true” in favour of useful cues such as “expected 3 to be even number” and avoiding implementation noise such as expect(cycleWheels % 2 === 0).toEqual(true) in favour of simply stating that you expect(cycleWheels).toBeEvenNumber().

Sponsors

🌩 Installation

npm

npm install jasmine-expect --save-dev

Bower

bower install jasmine-expect --save-dev

Manual

Downloads are available on the releases page.

📝 API

The Jasmine testing framework from Pivotal Labs comes with this default set of matchers:

expect().nothing()
expect().toBe(expected)
expect().toBeCloseTo(expected, precisionopt)
expect().toBeDefined()
expect().toBeFalse()
expect().toBeFalsy()
expect().toBeGreaterThan(expected)
expect().toBeGreaterThanOrEqual(expected)
expect().toBeInstanceOf(expected)
expect().toBeLessThan(expected)
expect().toBeLessThanOrEqual(expected)
expect().toBeNaN()
expect().toBeNegativeInfinity()
expect().toBeNull()
expect().toBePositiveInfinity()
expect().toBeTrue()
expect().toBeTruthy()
expect().toBeUndefined()
expect().toContain(expected)
expect().toEqual(expected)
expect().toHaveBeenCalled()
expect().toHaveBeenCalledBefore(expected)
expect().toHaveBeenCalledOnceWith()
expect().toHaveBeenCalledTimes(expected)
expect().toHaveBeenCalledWith()
expect().toHaveClass(expected)
expect().toHaveSize(expected)
expect().toMatch(expected)
expect().toThrow(expectedopt)
expect().toThrowError(expectedopt, messageopt)
expect().toThrowMatching(predicate)
expect().withContext(message)

and this default set of asymmetric matchers;

jasmine.any(Constructor);
jasmine.anything(mixed);
jasmine.arrayContaining(mixed);
jasmine.objectContaining(mixed);
jasmine.stringMatching(pattern);

Matchers

Jasmine-Matchers adds the following matchers:

expect(array).toBeArray();
expect(array).toBeArrayOfBooleans();
expect(array).toBeArrayOfNumbers();
expect(array).toBeArrayOfObjects();
expect(array).toBeArrayOfSize(number);
expect(array).toBeArrayOfStrings();
expect(array).toBeEmptyArray();
expect(array).toBeNonEmptyArray();
expect(boolean).toBeBoolean();
expect(date).toBeAfter(otherDate);
expect(date).toBeBefore(otherDate);
expect(date).toBeDate();
expect(date).toBeValidDate();
expect(fn).toBeFunction();
expect(fn).toThrowAnyError();
expect(fn).toThrowErrorOfType(constructorName);
expect(mixed).toBeCalculable();
expect(number).toBeEvenNumber();
expect(number).toBeGreaterThanOrEqualTo(otherNumber);
expect(number).toBeLessThanOrEqualTo(otherNumber);
expect(number).toBeNear(otherNumber, epsilon);
expect(number).toBeNumber();
expect(number).toBeOddNumber();
expect(number).toBeWholeNumber();
expect(number).toBeWithinRange(floor, ceiling);
expect(object).toBeEmptyObject();
expect(object).toBeNonEmptyObject();
expect(object).toBeObject();
expect(object).toHaveArray(memberName);
expect(object).toHaveArrayOfBooleans(memberName);
expect(object).toHaveArrayOfNumbers(memberName);
expect(object).toHaveArrayOfObjects(memberName);
expect(object).toHaveArrayOfSize(memberName, size);
expect(object).toHaveArrayOfStrings(memberName);
expect(object).toHaveBoolean(memberName);
expect(object).toHaveCalculable(memberName);
expect(object).toHaveDate(memberName);
expect(object).toHaveDateAfter(memberName, date);
expect(object).toHaveDateBefore(memberName, date);
expect(object).toHaveEmptyArray(memberName);
expect(object).toHaveEmptyObject(memberName);
expect(object).toHaveEmptyString(memberName);
expect(object).toHaveEvenNumber(memberName);
expect(object).toHaveFalse(memberName);
expect(object).toHaveHtmlString(memberName);
expect(object).toHaveIso8601(memberName);
expect(object).toHaveJsonString(memberName);
expect(object).toHaveMember(memberName);
expect(object).toHaveMethod(memberName);
expect(object).toHaveNonEmptyArray(memberName);
expect(object).toHaveNonEmptyObject(memberName);
expect(object).toHaveNonEmptyString(memberName);
expect(object).toHaveNumber(memberName);
expect(object).toHaveNumberWithinRange(memberName, floor, ceiling);
expect(object).toHaveObject(memberName);
expect(object).toHaveOddNumber(memberName);
expect(object).toHaveString(memberName);
expect(object).toHaveStringLongerThan(memberName, string);
expect(object).toHaveStringSameLengthAs(memberName, string);
expect(object).toHaveStringShorterThan(memberName, string);
expect(object).toHaveTrue(memberName);
expect(object).toHaveUndefined(memberName);
expect(object).toHaveWhitespaceString(memberName);
expect(object).toHaveWholeNumber(memberName);
expect(regexp).toBeRegExp();
expect(string).toBeEmptyString();
expect(string).toBeHtmlString();
expect(string).toBeIso8601();
expect(string).toBeJsonString();
expect(string).toBeLongerThan(otherString);
expect(string).toBeNonEmptyString();
expect(string).toBeSameLengthAs(otherString);
expect(string).toBeShorterThan(otherString);
expect(string).toBeString();
expect(string).toBeWhitespace();
expect(string).toEndWith(substring);
expect(string).toStartWith(substring);

Asymmetric Matchers

any.after(date);
any.arrayOfBooleans();
any.arrayOfNumbers();
any.arrayOfObjects();
any.arrayOfSize(number);
any.arrayOfStrings();
any.before(date);
any.calculable();
any.emptyArray();
any.emptyObject();
any.endingWith(string);
any.evenNumber();
any.greaterThanOrEqualTo(number);
any.iso8601();
any.jsonString();
any.lessThanOrEqualTo(number);
any.longerThan(string);
any.nonEmptyArray();
any.nonEmptyObject();
any.nonEmptyString();
any.oddNumber();
any.regExp();
any.sameLengthAs(string);
any.shorterThan(string);
any.startingWith(string);
any.whitespace();
any.wholeNumber();
any.withinRange(floor, ceiling);

🕹 Usage

Browser

Embed jasmine-matchers.js after Jasmine but before your tests.

Jest

Include the following in your package.json:

"unmockedModulePathPatterns": ["jasmine-expect"]

And the following at the top of your test suite:

import JasmineExpect from "jasmine-expect";

Karma

Integration is easy with the karma-jasmine-matchers plugin.

Node.js

Use the Jasmine CLI and include the path to where Jasmine Matchers is installed in the helpers array of your spec/support/jasmine.json.

{
  "spec_dir": "spec",
  "spec_files": ["../src/**/*.spec.js"],
  "helpers": ["../node_modules/jasmine-expect/index.js"],
  "stopSpecOnExpectationFailure": false,
  "random": false
}

TypeScript and Angular CLI Projects

If you are using TypeScript, you might want to npm install @types/jasmine-expect --save-dev in order to prevent your IDE from complaining about the new Matchers.

Also, if you run into TypeScript compilation errors when running your tests, add "jasmine-expect" to the "types" array in your tests’ tsconfig file.

As an example, for an Angular CLI based project, this would be your tsconfig.spec.json file:

{
  "extends": "../tsconfig.json",
  "compilerOptions": {
    "outDir": "../out-tsc/spec",
    "baseUrl": "./",
    "module": "commonjs",
    "target": "es5",
    "types": ["jasmine", "node", "jasmine-expect"]
  },
  "files": ["test.ts"],
  "include": ["**/*.spec.ts", "**/*.d.ts"]
}

Sublime Text

Jasmine-Matchers-Snippets or Jasmine-Matchers-ES6-Snippets can be installed with Package Control to ease development with Jasmine Matchers in Sublime Text.

Tern

There is a Plugin for Tern to auto-complete matchers in your Text Editor.

🌍 Browser Support

Jasmine-Matchers is tested on Travis CI and BrowserStack against the following environments.

Browser	Version Range
Android	9 - 11
Chrome	80 - 85
Edge	80 - 85
Firefox	76 - 80
iOS	10 - 14
Safari	10 - 13

🙋🏽‍♂️ Getting Help

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

👀 Other Projects

If you find my Open Source projects useful, please share them ❤️

• eslint-formatter-git-log
  ESLint Formatter featuring Git Author, Date, and Hash
• eslint-plugin-move-files
  Move and rename files while keeping imports up to date
• eslint-plugin-prefer-arrow-functions
  Convert functions to arrow functions
• ImageOptim-CLI
  Automates ImageOptim, ImageAlpha, and JPEGmini for Mac to make batch optimisation of images part of your automated build process.
• karma-benchmark
  Run Benchmark.js over multiple Browsers, with CI compatible output
• self-help
  Interactive Q&A Guides for Web and the Command Line
• syncpack
  Manage multiple package.json files, such as in Lerna Monorepos and Yarn Workspaces

🤓 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.