Jasmine2-custom-message NPM

jasmine2-custom-message

works with jasmine v2 (for work with jasmine v1.3 see jasmine-custom-message)

This script makes it possible to use your own failure message on any jasmine assertion.

Example

describe('the story', function() {
  it('should finish ok', function() {
    since('all cats are grey in the dark').
    expect('tiger').toEqual('kitty'); // => 'all cats are grey in the dark'
  });
});

Simple

All the magic happens in since function. That returns an object with a property expect. That contains no more than a wrapped jasmine expect function. That returns jasmine expectation object with a wrapped addExpectationResult function. That can replace an ordinary jasmine failure message with a newly generated one. That is generating based on a custom message you have supplied to since function as the first argument. That can be a primitive (except null and undefined), a function, or any other object. That is it.

Example

describe('test', function() {
  it('should be ok', function() {
    since(function() {
      return {'tiger': 'kitty'};
    }).
    expect(3).toEqual(4); // => '{"tiger":"kitty"}'
  });
});

Unobtrusive

You can use jasmine as you did before, since jasmine2-custom-message does not replace global jasmine expect function.

Example

describe('test', function() {
  it('should be ok', function() {
    expect(3).toEqual(4); // => ordinary jasmine message
  });
});

Powerful

You can use expected and actual values of the assertion in your custom message by:

Passing a function, and using this.actual and this.expected
Passing a string, and using #{actual} and #{expected}

You can include the full original message from Jasmine by:

Passing a function, and using this.message
Passing a string, and using #{message}

Examples using a function

describe('test', function() {
  it('should be ok', function() {
    since(function() {
      return this.actual + ' =/= ' + this.expected;
    }).
    expect(3).toEqual(4); // => '3 =/= 4'
  });
});

describe('multiple tests that need some context added to the message', function() {
    it('should be ok for all options', function() {
      // passes the 1st loop iteration, fails the 2nd
      [1, 2, 3, 4, 5].forEach(testOptionIndex => {
        since(function() {
          return 'for test option ' + testOptionIndex + ': ' + this.message;
        }).
        expect(testOptionIndex).toEqual(1); // => for test option 2: Expected 2 to equal 1.  
      });
    });
});

Example using a string

describe('test', function() {
  it('should be ok', function() {
    since('#{actual} =/= #{expected}').
    expect(3).toEqual(4); // => '3 =/= 4'
  });
});

describe('multiple tests that need some context added to the message', function() {
    it('should be ok for all options', function() {
      // passes the 1st loop iteration, fails the 2nd
      [1, 2, 3, 4, 5].forEach(testOptionIndex => {
        since('for test option ' + testOptionIndex + ': #{message}').
        expect(testOptionIndex).toEqual(1); // => for test option 2: Expected 2 to equal 1.  
      });
    });
});

Front-end usage

install the bower package from github

bower install jasmine2-custom-message --save-dev

include jasmine2-custom-message.js into your HTML file next to jasmine script

<script src="PATH-TO/jasmine.js"></script>
<script src="PATH-TO/jasmine2-custom-message.js"></script>

Node.js usage

install the bower package from github

$ bower install jasmine2-custom-message --save-dev

$ npm install jasmine2-custom-message --save-dev

require it in your spec file before your tests

require('jasmine2-custom-message');

or be explicit in any functional scope

var since = require('jasmine2-custom-message');

Change log

v0.9.0 - 2018.03.01

improved "format string" functionality: #{message} added for the original jasmine2 error message (kudos to Keith Zimmerman)
corrected output for toHaveBeenCalled matcher (kudos to Holger Jeromin)
updated protractor environment (kudos to Keith Zimmerman)
added typescript definitions (kudos to Holger Jeromin and Andrew N Marshall)
updated specs

v0.8.0 - 2015.08.05

implemented "format string" functionality: #{actual} and #{expected}
configured protractor environment
corrected displaying of colors in tests running through protractor
updated specs

v0.7.0 - 2014.10.23

fixed issue with custom failure messages on inverse assertions
updated specs

v0.6.0 - 2014.01.18 - BROKEN COMPATIBILITY!

all the magic moved into newly introduced since function
restored automatic initiation of the script upon inclusion (browser) or require (Node.js)
cleaned specs

v0.5.0 - 2014.01.15