Write Beautiful Specs with Custom Matchers
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- π© Installation
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- πΉ Usage
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A huge library of test matchers for a range of common use-cases, compatible with all versions of Jasmine and Jest.
Custom Matchers make tests easier to read and produce relevant and useful messages when they fail.
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()
.
npm install jasmine-expect --save-dev
bower install jasmine-expect --save-dev
Downloads are available on the releases page.
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);
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);
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);
Embed jasmine-matchers.js after Jasmine but before your tests.
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";
Integration is easy with the karma-jasmine-matchers plugin.
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
}
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"]
}
Jasmine-Matchers-Snippets or Jasmine-Matchers-ES6-Snippets can be installed with Package Control to ease development with Jasmine Matchers in Sublime Text.
There is a Plugin for Tern to auto-complete matchers in your Text Editor.
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 |
Get help with issues by creating a Bug Report or discuss ideas by opening a Feature Request.
If you find my Open Source projects useful, please share them β€οΈ
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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
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.