mocha-shared

Shared behaviour for Mocha, to help DRY your test suite.

Installation

In the root directory of your project, run the command:

npm install mocha-shared --save-dev

Then, in your javascript, add:

var shared = require('mocha-shared');

Methods

• behavior
• setup
• scenario
• forMany

behavior

Used to describe behaviour that is shared between multiple test cases. Behaviors should be used to wrap "it" blocks, and describe what something does.

e.g. "has status", "returns JSON"

ALIAS: #hasBehavior, #behavesLike

NOTE: For our British users, you an also use the "correct" spellings of #behaviour and #hasBehaviour

Setting a behavior:

API:

#behavior(description, fn)

• description (required; string)
• function (required; function signature may take ZERO or ONE arguments)

Example #1:

shared.behavior('is a string', function() {

  // shared behavior
  it('is a string', function() {
    expect(typeof this.word).to.equal('string');
  });

});

Example #2:

shared.behavior('contains letter', function(letter) {

  // shared behavior, based on function param
  it('contains the letter ' + letter, function() {
    expect(typeof this.word).to.contain(letter);
  });

});

Using a behavior:

API:

#behavior(description[, options])

• description (required; string)
• options (optional, injected into your shared behavior method as the first argument)

Example:

describe('hello', function(){

  before(function(){
    this.word = 'hello';
  });

  shared.behavior('is a string'); // must match our description text above EXACTLY
  // or scenario.hasBehavior('is a string');
  // or scenario.behavesLike('is a string');
  shared.behavior('contains the letter', 'h');

});

setup

Used to describe setup steps that are shared between multiple scenarios. These should not include expectations, but should include: before, beforeEach, after, afterEach, for setting up spies, mocks and stubs (for example).

e.g. "set title", "init HTTP request"

Configuring a setup:

API:

#setup(description, fn)

• description (required; string)
• function (required)

Example #1:

shared.setup('init string test', function() {

  // init our setup
  before(function(){
    this.isWord = function(word) {
      return (typeof word == 'string');
    };
  });

});

Example #2:

shared.setup('set word', function(word) {

  // init our setup
  before(function(){
    this.word = word;
  });

});

Using a setup:

API:

#setup(description[, options])

• description (required; string)
• options (optional, injected into your shared behavior method as the first argument)

Example:

describe('hello', function(){

  // include setup
  // must match our description text above EXACTLY
  shared.setup('init string test');
  shared.setup('set word', word);

  // test our expectations
  it('is a word', function(){
    expect(this.isWord(this.word)).to.be.truthy;
  });

});

scenario

Used to describe a scenario that is shared between multiple test cases. Scenarios should be used to wrap describe blocks, and encapsulate shared behaviors and setups.

e.g. "making a request with missing fields", "deleting a resource"

Setting a scenario:

API:

#scenario(description, fn)

• description (required; string)
• function (required; function signature may take ZERO or ONE arguments)

Example:

shared.scenario('word contains "h" and "e"', function(word) {

  describe('when the word is ' + word, function() {
    shared.setup('set word', word);
    shared.behavior('is a string');
    shared.behavior('contains the letter', 'h');
    shared.behavior('contains the letter', 'e');
  });

});

Using a scenario:

API:

#scenario(description[, options])

• description (required; string)
• options (optional, injected into your shared behavior method as the first argument)

Example:

describe('test suite', function() {

  shared.scenario('word contains "h" and "e"', 'horse');
  shared.scenario('word contains "h" and "e"', 'hello');

});

forMany

Used to apply a behavior/scenario to an array of inputs.

ALIAS: #for

Usage

API:

#forMany(values, [fn|description])

• values (required; array)
• fn (function; provides an iterator within the passed-in function)
• description (string; the description of the scenario you want applied to many)

**NOTE: ** This can be used to loop through setup, behaviors and scenarios within the anonymous function. The optional scenario string in the "shorthand" version is just sugar to help reduce repetition.

Example #1:

describe('test suite', function(){

  shared.forMany(['horse','hello'], function(word){
    shared.scenario('word contains "h" and "e"', word);
  });

});

Example #2 ("sugar" shorthand, for scenarios only):

describe('test suite', function(){

  shared.forMany(['horse','hello'], 'word contains "h" and "e"');
  // OR shared.for(['horse','hello'], 'word contains "h" and "e"');

});

Changelog

0.1.0

• Rename example to behavior
• Deprecate example
• Add aliases for behavior (hasBehavior, behavesLike)
• Add British aliases for behavior (behaviour, hasBehaviour), with the extra "u"
• Add setup for setting up tests
• Add forMany for iterative tests

0.2.0

• Add scenario for wrapping describe blocks in tests
• Add alias for forMany (for)
• forMany "sugar" string syntax now points to scenario, not behavior
• Adds deprecation notice for users attempting to call a behavior from forMany