jest-immutable-matchers

List of matchers

• toBeImmutable
• toBeIterableImmutable
• toBeKeyedImmutable
• toBeIndexedImmutable
• toBeAssociativeImmutable
• toBeOrderedImmutable
• toBeImmutableList
• toBeImmutableMap
• toBeImmutableOrderedMap
• toBeImmutableSet
• toBeImmutableOrderedSet
• toBeImmutableStack
• toBeImmutableSeq
• toEqualImmutable

Installation

Just run:

$ npm install --save-dev jest-immutable-matchers

Usage

Load these matchers in a beforeEach block, and then use them like any other matcher:

expect(Immutable.Map()).toBeImmutable()

TypeScript

This package includes the necessary declarations for TypeScript. Just make sure they get loaded in your project, for example by adding the package name to the types field in your tsconfig.json:

{
  "compilerOptions": {
    "module": "commonjs",
    "target": "es5",
    "types": [
      "jest",
      "jest-immutable-matchers"
    ]
  }
}

Then just load the matchers at runtime in your tests:

import * as matchers from 'jest-immutable-matchers';

describe('My suite', function () {
  beforeEach(function () {
    expect.extend(matchers);
  });

  it('passes if the object is immutable', function () {
    expect(Immutable.Map()).toBeImmutable();
  });

  it('passes if the immutable objects are equal', function () {
    expect(Immutable.Map({a: 1})).toEqualImmutable(Immutable.Map({a: 1}));
  });
});

ES2015

If you are using the new module syntax, import all exported matchers:

import * as matchers from 'jest-immutable-matchers';

describe('My suite', function () {
  beforeEach(function () {
    expect.extend(matchers);
  });

  it('passes if the object is immutable', function () {
    expect(Immutable.Map()).toBeImmutable();
  });

  it('passes if the immutable objects are equal', function () {
    expect(Immutable.Map({a: 1})).toEqualImmutable(Immutable.Map({a: 1}));
  });
});

Note that jest-immutable-matchers does not have a default export!

AMD/CommonJS

If you are using AMD or CommonJS, require normally:

var matchers = require('jest-immutable-matchers');

describe('My suite', function () {
  beforeEach(function () {
    expect.extend(matchers);
  });

  it('passes if the object is immutable', function () {
    expect(Immutable.Map()).toBeImmutable();
  });

  it('passes if the immutable objects are equal', function () {
    expect(Immutable.Map({a: 1})).toEqualImmutable(Immutable.Map({a: 1}));
  });
});

Global

Otherwise, use window['jest-immutable-matchers']:

var matchers = window['jest-immutable-matchers'];

describe('My suite', function () {
  beforeEach(function () {
    expect.extend(matchers);
  });

  it('passes if the object is immutable', function () {
    expect(Immutable.Map()).toBeImmutable();
  });

  it('passes if the immutable objects are equal', function () {
    expect(Immutable.Map({a: 1})).toEqualImmutable(Immutable.Map({a: 1}));
  });
});