postal.js/ext/pavlov.js
2011-09-21 01:12:55 -04:00

576 lines
19 KiB
JavaScript

/**
* Pavlov - Behavioral API over QUnit
*
* version 0.2.3
*
* http://michaelmonteleone.net/projects/pavlov
* http://github.com/mmonteleone/pavlov
*
* Copyright (c) 2009 Michael Monteleone
* Licensed under terms of the MIT License (README.markdown)
*/
(function(){
// capture reference to global scope
var globalScope = this;
// ===========
// = Helpers =
// ===========
// Trimmed versions of jQuery helpers for use only within pavlov
/**
* Iterates over an object or array
* @param {Object|Array} object object or array to iterate
* @param {Function} callback callback for each iterated item
*/
var each = function(object, callback) {
var name;
var i = 0;
var length = object.length;
if ( length === undefined ) {
for ( name in object ) {
if ( callback.call( object[ name ], name, object[ name ] ) === false ) {
break;
}
}
} else {
for ( var value = object[0];
i < length && callback.call( value, i, value ) !== false;
value = object[++i] ) {}
}
return object;
};
/**
* converts an array-like object to an array
* @param {Object} array array-like object
* @returns array
*/
var makeArray = function(array) {
var ret = [];
var i = array.length;
while( i ) { ret[--i] = array[i]; }
return ret;
};
/**
* returns whether or not an object is an array
* @param {Object} obj object to test
* @returns whether or not object is array
*/
var isArray = function(obj) {
return Object.prototype.toString.call(obj) === "[object Array]";
};
/**
* merges properties form one object to another
* @param {Object} dest object to receive merged properties
* @param {Object} src object containing properies to merge
*/
var extend = function(dest, src) {
for(var prop in src) {
dest[prop] = src[prop];
}
};
/**
* minimalist (and yes, non-optimal/leaky) event binder
* not meant for wide use. only for jquery-less internal use in pavlov
* @param {Element} elem Event-triggering Element
* @param {String} type name of event
* @param {Function} fn callback
*/
var addEvent = function(elem, type, fn){
if ( elem.addEventListener ) {
elem.addEventListener( type, fn, false );
} else if ( elem.attachEvent ) {
elem.attachEvent( "on" + type, fn );
}
};
// ====================
// = Example Building =
// ====================
var examples = [];
var currentExample;
/**
* Example Class
* Represents an instance of an example (a describe)
* contains references to parent and nested examples
* exposes methods for returning combined lists of before, after, and names
* @constructor
* @param {example} parent example to append self as child to (optional)
*/
function example(parent) {
// private
if(parent) {
// if there's a parent, append self as nested example
parent.children.push(this);
} else {
// otherwise, add this as a new root example
examples.push(this);
}
var thisExample = this;
/**
* Rolls up list of current and ancestors values for given prop name
* @param {String} prop Name of property to roll up
* @returns array of values corresponding to prop name
*/
var rollup = function(prop) {
var items = [];
var node = thisExample;
while(node !== null) {
items.push(node[prop]);
node = node.parent;
}
return items;
};
// public
// parent example
this.parent = parent ? parent : null;
// nested examples
this.children = [];
// name of this description
this.name = '';
// function to happen before all contained specs
this.before = function() {};
// function to happen after all contained specs
this.after = function() {};
// array of it() tests
this.specs = [];
/**
* rolls up this and ancestor's before functions
* @returns arrayt of functions
*/
this.befores = function(){
return rollup('before').reverse();
};
/**
* Rolls up this and ancestor's after functions
* @returns array of functions
*/
this.afters = function(){
return rollup('after');
};
/**
* Rolls up this and ancestor's description names, joined
* @returns string of joined description names
*/
this.names = function(){
return rollup('name').reverse().join(', ');
};
}
// ==============
// = Assertions =
// ==============
/**
* Collection of default-bundled assertion implementations
*/
var assertions = {
equals: function(actual, expected, message) {
equals(actual, expected, message);
},
isEqualTo: function(actual, expected, message) {
equals(actual, expected, message);
},
isNotEqualTo: function(actual, expected, message) {
ok(actual !== expected, message);
},
isSameAs: function(actual, expected, message) {
same(actual, expected, message);
},
isNotSameAs: function(actual, expected, message) {
ok(!QUnit.equiv(actual, expected), message);
},
isTrue: function(actual, message) {
ok(actual, message);
},
isFalse: function(actual, message) {
ok(!actual, message);
},
isNull: function(actual, message) {
ok(actual === null, message);
},
isNotNull: function(actual, message) {
ok(actual !== null, message);
},
isDefined: function(actual, message) {
ok(typeof(actual) !== 'undefined', message);
},
isUndefined: function(actual, message) {
ok(typeof(actual) === 'undefined', message);
},
pass: function(actual, message) {
ok(true, message);
},
fail: function(actual, message) {
ok(!true, message);
},
throwsException: function(actual, expectedErrorDescription, message) {
/* can optionally accept expected error message */
try{
actual();
ok(!true, message);
} catch(e) {
if(arguments.length > 1) {
ok(e === expectedErrorDescription, message);
} else {
ok(true, message);
}
}
}
};
/**
* AssertionHandler
* represents instance of an assertion regarding a particular
* actual value, and provides an api around asserting that value
* against any of the bundled assertion handlers and custom ones.
* @constructor
* @param {Object} value A test-produced value to assert against
*/
var assertHandler = function(value) {
this.value = value;
};
/**
* Appends assertion methods to the assertHandler prototype
* For each provided assertion implementation, adds an identically named
* assertion function to assertionHandler prototype which can run impl
* @param {Object} asserts Object containing assertion implementations
*/
var addAssertions = function(asserts) {
each(asserts, function(name, fn){
assertHandler.prototype[name] = function() {
// implement this handler against backend
// by pre-pending assertHandler's current value to args
var args = makeArray(arguments);
args.unshift(this.value);
fn.apply(this, args);
};
});
};
// pre-add all the default bundled assertions
addAssertions(assertions);
// =====================
// = Pavlov Public API =
// =====================
/**
* Object containing methods to be made available as public API
*/
var api = {
/**
* Initiates a new Example context
* @param {String} description Name of what's being "described"
* @param {Function} fn Function containing description (before, after, specs, nested examples)
*/
describe: function(description, fn) {
if(arguments.length < 2) {
throw("both 'description' and 'fn' arguments are required");
}
// capture reference to current example before construction
var originalExample = currentExample;
try{
// create new current example for construction
currentExample = new example(currentExample);
currentExample.name = description;
fn();
} finally {
// restore original reference after construction
currentExample = originalExample;
}
},
/**
* Sets a function to occur before all contained specs and nested examples' specs
* @param {Function} fn Function to be executed
*/
before: function(fn) {
if(arguments.length === 0) {
throw("'fn' argument is required");
}
currentExample.before = fn;
},
/**
* Sets a function to occur after all contained tests and nested examples' tests
* @param {Function} fn Function to be executed
*/
after: function(fn) {
if(arguments.length === 0) {
throw("'fn' argument is required");
}
currentExample.after = fn;
},
/**
* Creates a spec (test) to occur within an example
* When not passed fn, creates a spec-stubbing fn which asserts fail "Not Implemented"
* @param {String} specification Description of what "it" "should do"
* @param {Function} fn Function containing a test to assert that it does indeed do it (optional)
*/
it: function(specification, fn) {
if(arguments.length === 0) {
throw("'specification' argument is required");
}
thisApi = this;
if(fn) {
currentExample.specs.push([specification, fn]);
} else {
// if not passed an implementation, create an implementation that simply asserts fail
thisApi.it(specification, function(){thisApi.assert.fail('Not Implemented');});
}
},
/**
* Generates a row spec for each argument passed, applying
* each argument to a new call against the spec
* @returns an object with an it() function for defining
* function to be called for each of given's arguments
* @param {Array} arguments either list of values or list of arrays of values
*/
given: function() {
if(arguments.length === 0) {
throw("at least one argument is required");
}
var args = makeArray(arguments);
var thisIt = this.it;
return {
/**
* Defines a row spec (test) which is applied against each
* of the given's arguments.
*/
it: function(specification, fn) {
each(args, function(){
var arg = this;
thisIt("given " + arg + ", " + specification, function(){
fn.apply(this, isArray(arg) ? arg : [arg]);
});
});
}
};
},
/**
* Assert a value against any of the bundled or custom assertions
* @param {Object} value A value to be asserted
* @returns an assertHandler instance to fluently perform an assertion with
*/
assert: function(value) {
return new assertHandler(value);
},
/**
* specifies test runner to synchronously wait
* @param {Number} ms Milliseconds to wait
* @param {Function} fn Function to execute after ms has
* passed before resuming
*/
wait: function(ms, fn) {
if(arguments.length < 2) {
throw("both 'ms' and 'fn' arguments are required");
}
stop();
QUnit.specify.globalObject.setTimeout(function(){
fn();
start();
}, ms);
}
};
// extend api's assert function for easier syntax for blank pass and fail
extend(api.assert, {
/**
* Shortcuts assert().pass() with assert.pass()
* @param {String} message Assertion message (optional)
*/
pass: function(message){
(new assertHandler()).pass(message);
},
/**
* Shortcuts assert().fail() with assert.fail()
* @param {String} message Assertion message (optional)
*/
fail: function(message){
(new assertHandler()).fail(message);
}
});
/**
* Extends a function's scope
* applies the extra scope to the function returns un-run new version of fn
* inspired by Yehuda Katz's metaprogramming Screw.Unit
* different in that new function can still accept all parameters original function could
* @param {Function} fn Target function for extending
* @param {Object} thisArg Object for the function's "this" to refer
* @param {Object} extraScope object whose members will be added to fn's scope
* @returns Modified version of original function with extra scope. Can still
* accept parameters of original function
*/
var extendScope = function(fn, thisArg, extraScope) {
// get a string of the fn's parameters
var params = fn.toString().match(/\(([^\)]*)\)/)[1];
// get a string of fn's body
var source = fn.toString().match(/^[^\{]*\{((.*\s*)*)\}/m)[1];
// create a new function with same parameters and
// body wrapped in a with(extraScope){ }
fn = new Function(
"extraScope" + (params ? ", " + params : ""),
"with(extraScope){" + source + "}");
// returns a fn wrapper which takes passed args,
// pre-pends extraScope arg, and applies to modified fn
return function(){
var args = [extraScope];
each(arguments,function(){
args.push(this);
});
fn.apply(thisArg, args);
};
};
/**
* Top-level Specify method. Declares a new QUnit.specify context
* @param {String} name Name of what's being specified
* @param {Function} fn Function containing exmaples and specs
*/
var specify = function(name, fn) {
if(arguments.length < 2) {
throw("both 'name' and 'fn' arguments are required")
}
examples = [];
currentExample = null;
// set the test suite title
document.title = name + " Specifications";
addEvent(window,'load',function(){
// document.getElementsByTag('h1').innerHTML = name;
var h1s = document.getElementsByTagName('h1');
if(h1s.length > 0)
h1s[0].innerHTML = document.title;
});
if(QUnit.specify.globalApi) {
// if set to extend global api,
// extend global api and run example builder
extend(globalScope, api);
fn();
} else {
// otherwise, extend example builder's scope with api
// and run example builder
extendScope(fn, this, api)();
}
// compile examples into flat qunit statements
var qunitStatements = compile(examples);
// run qunit tests
each(qunitStatements, function(){ this(); });
};
// ==========================================
// = Example-to-QUnit Statement Compilation =
// ==========================================
/**
* Compiles nested set of examples into flat array of QUnit statements
* @param {Array} examples Array of possibly nested Example instances
* @returns array of QUnit statements each wrapped in an anonymous fn
*/
var compile = function(examples) {
var statements = [];
/**
* Comples a single example and its children into QUnit statements
* @param {Example} example Single example instance
* possibly with nested instances
*/
var compileDescription = function(example) {
// get before and after rollups
var befores = example.befores();
var afters = example.afters();
// create a module with setup and teardown
// that executes all current befores/afters
statements.push(function(){
module(example.names(), {
setup: function(){
each(befores, function(){ this(); });
},
teardown: function(){
each(afters, function(){ this(); });
}
});
});
// create a test for each spec/"it" in the example
each(example.specs, function(){
var spec = this;
statements.push(function(){
test(spec[0],spec[1]);
});
});
// recurse through example's nested examples
each(example.children, function() {
compileDescription(this);
});
};
// compile all root examples
each(examples, function() {
compileDescription(this, statements);
});
return statements;
};
// =====================
// = Expose Public API =
// =====================
// extend QUnit
QUnit.specify = specify;
// add global settings onto QUnit.specify
extend(specify, {
version: '0.2.3',
globalApi: false, // when true, adds api to global scope
extendAssertions: addAssertions, // function for adding custom assertions
globalObject: window // injectable global containing setTimeout and pals
});
})();