lib/subject.js

subject.js - Subject-style setups/teardowns.

module.exports = (function() { "use strict"; var assert = require('assert') , path = require('path') , $S = { }; // main exports

_infections list

Array of function names to adds to global when infect() is called.

$S._infections = 'subject,property'.split(',');

_before( func ) and _after( func ) hook

Helper function that adds the supplied function to the before() and after() hook provided by mocha. This is provided in case you want to override the behavior of the before() and after() hook that is used by mocha-subject.

NOTE: Mocha rebuilds its before() and after() function after every test run so you must take care not to capture these variables and re-use it across different run of the test because it will produce unpredictable result. These two functions also helps in this regard. (Re-retreiving the value of global.before and global.after hook after every run.)

$S._before = function(func) { return global.before(func); }; $S._after = function(func) { return global.after(func); };

infect()

Adds subject() and property() method to global scope so it can be used without referencing mocha-subject.

$S.infect = function() { for (var i = 0; i < $S._infections.length; i++) global[$S._infections[i]] = $S[$S._infections[i]]; };

disinfect()

Removes all functions added by infect() from global scope.

$S.disinfect = function() { for (var i = 0; i < $S._infections.length; i++) delete global[$S._infections[i]]; };

subject( name, object )

Adds the given object to current mocha test context using the specified name in a before hook and removes it afterwards in an after hook.

$S.subject = function(name, object) { assert(typeof name === 'string', 'name argument missing or not a string'); assert(typeof object !== 'undefined', 'object argument is undefined'); $S._before(function() { this[name] = object;

TODO: Is there a way to track subjects hierarchy without modifying the context? storing states ourselves is probably not a good idea.

if (!this.__subjects) { Object.defineProperty(this, '__subjects', { enumerable: false , configurable: true // required for delete , value: [] }); } this.__subjects.push(object); }); $S._after(function() { delete this[name]; this.__subjects.pop(); if (!this.__subjects.length) { delete this.__subjects; } }); };

property( name, [key] )

Take property name from the nearest subject object and adds it to current mocha test context using the specified key (or the same name as the property if key is not specified.)

$S.property = function(name, contextKey) { assert(typeof name === 'string', 'name argument missing or not a string'); if (typeof contextKey === 'undefined') contextKey = name; assert(typeof contextKey === 'string', 'contextKey argument not a string'); $S._before(function() { var subject = this.__subjects[this.__subjects.length - 1]; this[contextKey] = subject[name]; }); $S._after(function() { delete this[contextKey]; }); };

return $S; })();