I am testing a class, let's call it ClassUnderTest using another class, let's call it OtherClass. In my Test I do:
$OtherClassStub = $this->createStub(OtherClass::class);
$OtherClassStub->method(...)
->willReturn(...);
$ClassUnderTest->otherClass = $OtherClassStub;
That works. But when the $ClassUnderTest calls new OtherClass(), the original OtherClass class is created instead of the stub.
How can I achieve that every possible instance of OtherClass in the context of the test is replaced by the stub?
From your description I infer that in principle you have something like this:
class OtherClass {
protected function someMethod(): bool
{
// determine $x ...
return $x;
}
}
class ClassUnderTest {
public OtherClass $otherClass;
public function methodToBeTested(): bool
{
$otherClass = new OtherClass();
return $otherClass->someMethod();
}
}
class ClassUnderTestTest extends TestCase {
public function testMethodToBeTested(): void
{
$otherClassStub = $this->createStub(OtherClass::class);
$otherClassStub->method('someMethod')
->willReturn(true);
$classUnderTest = new ClassUnderTest();
$classUnderTest->otherClass = $otherClassStub;
$result = $classUnderTest->methodToBeTested();
$this->assertTrue($result);
}
}
Now the assertion in your test may hold or it may fail. Why? Because you are not calling the method you stubbed on the $otherClassStub. Instead you instantiate a new $otherClass object in the method you're testing (or somewhere down the line).
Either your ClassUnderTest should always use the OtherClass object from the ClassUndertTest::otherClass attribute (assuming that's why you put it there in the first place).
Or you could use some other form of dependency injection, e.g. by using a framework like Symfony or Laravel. (In the case of Symfony you can even use only the DependencyInjection Component, no idea if that's possible with Laravel, too.)
The simple answer to your actual question is: you cannot change the behaviour of the new keyword. Calling new on a class will always instantiate a new object based on exactly that class, unless the constructor of that class defines something else.
(You might want to get the concept of classes and objects straight, your code example as well as your question seem to indicate that you're not quite clear on that. Maybe reading up on that as well as on the concept of dependency injection will help you.)
Perhaps a solution to your problem is presented here:
How to Build a PHP Plugin Module System
This is one way to load classes as plugins and they can be called from each other. With modifying this system a bit, you can create as many "new OtherClass()" as you like from your code and still access everything from other classes. If you want multiple instances of a class, perhaps modify it into this direction:
function load ($module,$instance) {
if (isset($this->$module->$instance)) { return true; }
From above link:
<?php
class Core {
// (A) PROPERTIES
public $error = ""; // LAST ERROR MESSAGE
public $pdo = null; // DATABASE CONNECTION
public $stmt = null; // SQL STATEMENT
public $lastID = null; // LAST INSERT/UPDATE ID
// (B) LOAD SPECIFIED MODULE
// $module : module to load
function load ($module) {
// (B1) CHECK IF MODULE IS ALREADY LOADED
if (isset($this->$module)) { return true; }
// (B2) EXTEND MODULE ON CORE OBJECT
$file = PATH_LIB . "LIB-$module.php";
if (file_exists($file)) {
require $file;
$this->$module = new $module();
// EVIL POINTER - ALLOW OBJECTS TO ACCESS EACH OTHER
$this->$module->core =& $this;
$this->$module->error =& $this->error;
$this->$module->pdo =& $this->pdo;
$this->$module->stmt =& $this->stmt;
return true;
} else {
$this->error = "$file not found!";
return false;
}
}
}
ps. thank you for the mod, who made me work a bit more to keep this answer online. the answer is so much better now.
This four year old question uses third party libraries which I am a little dubious about.
For testing purposes only, I want to redefine a static method of one of my classes. Take the following example:
class Driver {
public static function getVersion() : string
{
// Retrieves a version from a system executable
return some_system_call();
}
}
class Module {
public function methodToTest()
{
if (Driver::getVersion() === '4.0.0') {
// allow for additional options/methods
} else {
// use a subset
}
}
}
I need for the Driver::getVersion to return different version strings. I would usually mock the class, but since this is neither injected nor an instance, it's not going to work.
I could change the source, adding in methods and property testing, so that the classes being tested would never need to call Driver, but, in my opinion, refactoring the code just to make tests "work" is not a solution.
I'm thinking along the lines of creating another Driver class and somehow loading it in place of the original.
How can I do this?
You might wanna use smth like:
class Module
{
private $version;
public function __construct($version){
$this->version = $version;
}
public function methodToTest()
{
if ($this->version === '4.0.0') {
// allow for additional options/methods
} else {
// use a subset
}
}
}
or another option would be injecting not version but a provider for that (if you know you will have some bit of complicated logic for versioning control -- so you can split the logic between Module and Provider as appropriate):
class Module
{
private $versionProvider;
public function __construct($provider){
$this->versionProvdier = $provider;
}
public function methodToTest()
{
if ($this->versionProvider->getVersion() === '4.0.0') {
// it could be even $this->versionProvider->newFeaturesAreSupported()
} else {
// some other stuff
}
}
}
and still another could be implementing some proxy class like
class Module
{
public function methodToTest()
{
$myMonostateProxy = new MyMonostateProxy();
$version = $myMonostateProxy->getVersion();
if ($version === '4.0.0') {
// allow for additional options/methods
} else {
// use a subset
}
}
}
so you can mock your monostate separately (probably via reflectioning on privtates or via its public interface, anyway don't forget to tearDown it). Real implementation of it would just call that uncontrollable Driver::getVersion().
I think first two options are cleaner but require some efforts for creation (as you need some injection to perform).
Third has that hidden dependecy and is somewhat tricky in testing and thus not quite clean and needs more efforts to maintaine but hides all that choice stuff inside itself making regular usage easier.
class Driver {
private static $testVersion;
public static function setTestVersion(string $testVersion = null)
{
static::$testVersion = $testVersion;
}
public static function getVersion() : string
{
if (static::$testVersion !== null) {
return static::$testVersion;
}
// Retrieves a version from a system executable
return some_system_call();
}
}
You could register a class loader that is somehow made aware of the testing and loads a modified Driver class from a different location.
For pages that must always be on the website (only 1, not more, like a homepage), I wanted to make an extension. The page should be created when I run dev/build and cannot be created, deleted, unpublished or archived in the CMS. It can be edited however.
Everthing seems to work just fine except the canCreate function. It seems as this function doesn't do much for the CMS when it's on a(n) (Data)Extension. When I'm on .../admin/pages/add I can still create the Page as many times as I want.
If I move the canCreate to the HomePage class, it does work. But I want it in my extension :-)
class OnePage extends DataExtension
{
public function requireDefaultRecords()
{
if($this->canCreate()) {
$page = $this->owner;
$page->Title = $this->owner->className;
$page->write();
$page->publish('Stage', 'Live');
$page->flushCache();
}
}
public function canCreate($member = null)
{
return $this->owner->get()->count() == 0;
}
public function canDeleteFromLive($member = null)
{
return false;
}
public function canArchive($member = null)
{
return false;
}
}
class HomePage extends Page
{
private static $extensions = [
'OnePage'
];
}
Am I doing this the right way or am I missing something?
EDIT
The canCreate method works just fine, so I can solve it like this;
class HomePage extends Page
{
public function canCreate($member = null)
{
return $this->get()->count() == 0;
}
}
This has the desired effect and works like a charm. However, the question is about putting the canCreate method in the Extension. That should work aswell, right?
Well, $this->owner->get() won't work. $this->owner always returns the actual object, not a DataList. It should work like:
public function canCreate() {
$className = $this->owner->ClassName;
return $className::get()->count() == 0;
}
BTW: if you plan to release a module of this please consider another name, I already have published https://github.com/wernerkrauss/silverstripe-onepage/ for making simple onepage-sites utilizing the SiteTree
I have a PHP web application built with CodeIgniter MVC framework. I wish to test various controller classes. I'm using Toast for unit testing. My controllers have no state, everything they process is either saved into session or passed to view to display. Creating a mock session object and testing whether that works properly is straightforward (just create a mock object and inject it with $controller->session = $mock).
What I don't know, is how to work with views. In CodeIgniter, views are loaded as:
$this->load->view($view_name, $vars, $return);
Since I don't want to alter CI code, I though I could create a mock Loader and replace the original. And here lies the problem, I cannot find a way to derive a new class from CI_Loader.
If I don't include the system/libraries/Loader.php file, the class CI_Loader is undefined and I cannot inherit from it:
class Loader_mock extends CI_Loader
If I do include the file (using require_once), I get the error:
Cannot redeclare class CI_Loader
Looks like CI code itself does not use require_once from whatever reason.
Does anyone here have experience with unit testing CodeIgniter powered applications?
Edit: I tried to inject a real loader object at run-time into a mock class, and redirect all calls and variables with __call, __set, __get, __isset and __unset. But, it does not seem to work (I don't get any errors though, just no output, i.e. blank page from Toast). Here's the code:
class Loader_mock
{
public $real_loader;
public $varijable = array();
public function Loader_mock($real)
{
$this->real_loader = $real;
}
public function __call($name, $arguments)
{
return $this->real_loader->$name($arguments);
}
public function __set($name, $value)
{
return $this->real_loader->$name = $value;
}
public function __isset($name)
{
return isset($this->real_loader->$name);
}
public function __unset($name)
{
unset($this->loader->$name);
}
public function __get($name)
{
return $this->real_loader->$name;
}
public function view($view, $vars = array(), $return = FALSE)
{
$varijable = $vars;
}
}
Alternatively, you could do this:
$CI =& get_instance();
$CI = load_class('Loader');
class MockLoader extends CI_Loader
{
function __construct()
{
parent::__construct();
}
}
Then in your controller do $this->load = new MockLoader().
My current solution is to alter the CodeIgniter code to use require_once instead of require. Here's the patch I'm going to send to CI developers in case someone needs to do the same until they accept it:
diff --git a/system/codeigniter/Common.php b/system/codeigniter/Common.php
--- a/system/codeigniter/Common.php
+++ b/system/codeigniter/Common.php
## -100,20 +100,20 ## function &load_class($class, $instantiate = TRUE)
// folder we'll load the native class from the system/libraries folder.
if (file_exists(APPPATH.'libraries/'.config_item('subclass_prefix').$class.EXT))
{
- require(BASEPATH.'libraries/'.$class.EXT);
- require(APPPATH.'libraries/'.config_item('subclass_prefix').$class.EXT);
+ require_once(BASEPATH.'libraries/'.$class.EXT);
+ require_once(APPPATH.'libraries/'.config_item('subclass_prefix').$class.EXT);
$is_subclass = TRUE;
}
else
{
if (file_exists(APPPATH.'libraries/'.$class.EXT))
{
- require(APPPATH.'libraries/'.$class.EXT);
+ require_once(APPPATH.'libraries/'.$class.EXT);
$is_subclass = FALSE;
}
else
{
- require(BASEPATH.'libraries/'.$class.EXT);
+ require_once(BASEPATH.'libraries/'.$class.EXT);
$is_subclass = FALSE;
}
}
I can't help you much with the testing, but I can help you extend the CI library.
You can create your own MY_Loader class inside /application/libraries/MY_Loader.php.
<?php
class MY_Loader extends CI_Loader {
function view($view, $vars = array(), $return = FALSE) {
echo 'My custom code goes here';
}
}
CodeIgniter will see this automatically. Just put in the functions you want to replace in the original library. Everything else will use the original.
For more info check out the CI manual page for creating core system classes.
I'm impressed by the code you are trying to use.
So now I'm wondering how the 'Hooks' class of CodeIgniter could be of any help to your problem?
http://codeigniter.com/user_guide/general/hooks.html
Kind regards,
Rein Groot
The controller should not contain domain logic, so unit tests make no sense here.
Instead I would test the controllers and views with acceptance tests.
Is there any way to redefine a class or some of its methods without using typical inheritance? For example:
class third_party_library {
function buggy_function() {
return 'bad result';
}
function other_functions(){
return 'blah';
}
}
What can I do to replace buggy_function()? Obviously this is what I would like to do
class third_party_library redefines third_party_library{
function buggy_function() {
return 'good result';
}
function other_functions(){
return 'blah';
}
}
This is my exact dilemma: I updated a third party library that breaks my code. I don't want to modify the library directly, as future updates could break the code again. I'm looking for a seamless way to replace the class method.
I've found this library that says it can do it, but I'm wary as it's 4 years old.
EDIT:
I should have clarified that I cannot rename the class from third_party_library to magical_third_party_library or anything else because of framework limitations.
For my purposes, would it be possible to just add a function to the class? I think you can do this in C# with something called a "partial class."
It's called monkey patching. But, PHP doesn't have native support for it.
Though, as others have also pointed out, the runkit library is available for adding support to the language and is the successor to classkit. And, though it seemed to have been abandoned by its creator (having stated that it wasn't compatible with PHP 5.2 and later), the project does now appear to have a new home and maintainer.
I still can't say I'm a fan of its approach. Making modifications by evaluating strings of code has always seemed to me to be potentially hazardous and difficult to debug.
Still, runkit_method_redefine appears to be what you're looking for, and an example of its use can be found in /tests/runkit_method_redefine.phpt in the repository:
runkit_method_redefine('third_party_library', 'buggy_function', '',
'return \'good result\''
);
runkit seems like a good solution but its not enabled by default and parts of it are still experimental. So I hacked together a small class which replaces function definitions in a class file. Example usage:
class Patch {
private $_code;
public function __construct($include_file = null) {
if ( $include_file ) {
$this->includeCode($include_file);
}
}
public function setCode($code) {
$this->_code = $code;
}
public function includeCode($path) {
$fp = fopen($path,'r');
$contents = fread($fp, filesize($path));
$contents = str_replace('<?php','',$contents);
$contents = str_replace('?>','',$contents);
fclose($fp);
$this->setCode($contents);
}
function redefineFunction($new_function) {
preg_match('/function (.+)\(/', $new_function, $aryMatches);
$func_name = trim($aryMatches[1]);
if ( preg_match('/((private|protected|public) function '.$func_name.'[\w\W\n]+?)(private|protected|public)/s', $this->_code, $aryMatches) ) {
$search_code = $aryMatches[1];
$new_code = str_replace($search_code, $new_function."\n\n", $this->_code);
$this->setCode($new_code);
return true;
} else {
return false;
}
}
function getCode() {
return $this->_code;
}
}
Then include the class to be modified and redefine its methods:
$objPatch = new Patch('path_to_class_file.php');
$objPatch->redefineFunction("
protected function foo(\$arg1, \$arg2)
{
return \$arg1+\$arg2;
}");
Then eval the new code:
eval($objPatch->getCode());
A little crude but it works!
For people that are still looking for this answer.
You should use extends in combination with namespaces.
like this:
namespace MyCustomName;
class third_party_library extends \third_party_library {
function buggy_function() {
return 'good result';
}
function other_functions(){
return 'blah';
}
}
Then to use it do like this:
use MyCustomName\third_party_library;
$test = new third_party_library();
$test->buggy_function();
//or static.
third_party_library::other_functions();
For the sake of completeness - monkey patching is available in PHP through runkit. For details, see runkit_method_redefine().
How about wrapping it in another class like
class Wrapper {
private $third_party_library;
function __construct() { $this->third_party_library = new Third_party_library(); }
function __call($method, $args) {
return call_user_func_array(array($this->third_party_library, $method), $args);
}
}
Yes, it's called extend:
<?php
class sd_third_party_library extends third_party_library
{
function buggy_function() {
return 'good result';
}
function other_functions(){
return 'blah';
}
}
I prefixed with "sd". ;-)
Keep in mind that when you extend a class to override methods, the method's signature has to match the original. So for example if the original said buggy_function($foo, $bar), it has to match the parameters in the class extending it.
PHP is pretty verbose about it.
Zend Studio and PDT (eclipse based ide) have some built in refractoring tools. But there are no built in methods to do this.
Also you wouldn't want to have bad code in your system at all. Since it could be called upon by mistake.
I've modified the code from the answer by #JPhilly and made it possible to rename a the patched class to avoid errors.
Also, I've changed the regex that identifies the about-to-be-replaced function to fit cases where the replaced function doesn't have any class access modifiers in front of its name
Hope it helps.
class Patch {
private $_code;
public function __construct($include_file = null) {
if ( $include_file ) {
$this->includeCode($include_file);
}
}
public function setCode($code) {
$this->_code = $code;
}
public function includeCode($path) {
$fp = fopen($path,'r');
$contents = fread($fp, filesize($path));
$contents = str_replace('<?php','',$contents);
$contents = str_replace('?>','',$contents);
fclose($fp);
$this->setCode($contents);
}
function redefineFunction($new_function) {
preg_match('/function ([^\(]*)\(/', $new_function, $aryMatches);
$func_name = trim($aryMatches[1]);
// capture the function with its body and replace it with the new function
if ( preg_match('/((private|protected|public)?\s?function ' . $func_name .'[\w\W\n]+?)(private|protected|public|function|class)/s', $this->_code, $aryMatches) ) {
$search_code = $aryMatches[1];
$new_code = str_replace($search_code, $new_function."\n\n", $this->_code);
$this->setCode($new_code);
return true;
} else {
return false;
}
}
function renameClass($old_name, $new_name) {
$new_code = str_replace("class $old_name ", "class $new_name ", $this->_code);
$this->setCode($new_code);
}
function getCode() {
return $this->_code;
}
}
This is how I've used it to patch a Wordpress plugin:
$objPatch = new Patch(ABSPATH . 'wp-content/plugins/a-plugin/code.php');
$objPatch->renameClass("Patched_AClass", "Patched_Patched_AClass"); // just to avoid class redefinition
$objPatch->redefineFunction("
function default_initialize() {
echo 'my patched function';
}");
eval($objPatch->getCode());
$result = new Patched_AClass();
If the library is explicitly creating the bad class and not using a locater or dependency system you are out of luck. There is no way to override a method on another class unless you subclass.
The solution might be to create a patch file that fixes the library, so you can upgrade the library and re-apply the patch to fix that specific method.
You might be able to do this with runkit. http://php.net/runkit
You can make a copy of the library class, with everything the same except the class name. Then override that renamed class.
It's not perfect, but it does improve the visibility of the extending class's changes. If you fetch the library with something like Composer, you'll have to commit the copy to source control and update it when you update the library.
In my case it was an old version of https://github.com/bshaffer/oauth2-server-php. I modified the library's autoloader to fetch my class file instead. My class file took on the original name and extended a copied version of one of the files.
Since you always have access to the base code in PHP, redefine the main class functions you want to override as follows, this should leave your interfaces intact:
class third_party_library {
public static $buggy_function;
public static $ranOnce=false;
public function __construct(){
if(!self::$ranOnce){
self::$buggy_function = function(){ return 'bad result'; };
self::$ranOnce=true;
}
.
.
.
}
function buggy_function() {
return self::$buggy_function();
}
}
You may for some reason use a private variable but then you will only be able to access the function by extending the class or logic inside the class. Similarly it's possible you'd want to have different objects of the same class have different functions. If so, do't use static, but usually you want it to be static so you don't duplicate the memory use for each object made. The 'ranOnce' code just makes sure you only need to initialize it once for the class, not for every $myObject = new third_party_library()
Now, later on in your code or another class - whenever the logic hits a point where you need to override the function - simply do as follows:
$backup['buggy_function'] = third_party_library::$buggy_function;
third_party_library::$buggy_function = function(){
//do stuff
return $great_calculation;
}
.
.
. //do other stuff that needs the override
. //when finished, restore the original function
.
third_party_library::$buggy_function=$backup['buggy_function'];
As a side note, if you do all your class functions this way and use a string-based key/value store like public static $functions['function_name'] = function(...){...}; this can be useful for reflection. Not as much in PHP as other languages though because you can already grab the class and function names, but you can save some processing and future users of your class can use overrides in PHP. It is however, one extra level of indirection, so I would avoid using it on primitive classes wherever possible.
There's alway extending the class with a new, proper, method and calling that class instead of the buggy one.
class my_better_class Extends some_buggy_class {
function non_buggy_function() {
return 'good result';
}
}
(Sorry for the crappy formatting)