I need to verify that the object's state is not affected by a mutator call that is expected to generate an error. I thought I could do:
function testWhatever(){
try{
// setup $obj
$this->expectException(WhateverException::CLASS);
// code that throws
}finally{
// assert that $obj's state is still valid
}
}
But I immediately realized it would certainly create some issues with PHPUnit (and it indeed does) if the code within finally also throws for whatever reason.
What are my options to perform some assertions after the exception has thrown, possibly without being too acrobatic with try/catch/rethrow and without repeating "code that throws" twice? Something with equivalent functionality to the following, which is not allowed:
function testWhatever(){
try{
// setup $obj
$this->expectException(WhateverException::CLASS);
// code that throws
}finally{
$this->expectException(null);
// assert that $obj's state is still valid
}
}
You can just use an ordinary try / catch / finally
function testFoobar()
{
// setup code
try {
// code that throws
$this->fail("Code didn't throw!");
} catch (ExpectedException $e) {
// verify exception message
} finally {
// verify other things
}
}
You could use two tests and make them depend on each other (just make your first test succeed on Exception
/**
* #depends testWhatever
*/
public function testSomethingAfterException() {
// more tests to run
}
Related
I need some function that will accept a function as the parameter and will run it in try {} catch (Exception $e) {}. If it runs successfully, do nothing, otherwise, throw new Exception. That's something like function-checker, which checks functions if they ran successfully. Anybody can help me or give advice?
Thanks for any replies.
The function should work like that:
function itwillfail () {
echo 10 / 0;
}
check("itwillfail");
Output: Caught exception: Custom exception text here, because it has been thrown as custom.
("check" is that function I need)
What I tried:
function check($func) {
try {
call_user_func($func);
} catch (Exception $e) {
throw new Exception("Custom text here.");
}
}
EDIT: More explained: I need to create function, which do the same as "try" and a lot of different "catch"es for different types of exceptions.
Summarizing your question:
You want a way to call a custom function from a string variable (which you have already figured out that would be via call_user_func($var);.
You then want that function to throw a custom exception error
Confused
What is not clear is the reason you would opt to not define your error handler using the set_error_handler function which would effectively do what your asking and set a switch statement to output different messages based on the error generated.
Example
The following example is not using a call_user_func but it effectively allows you to write how the error will be handled
<?php
function myerror($error_no, $error_msg) {
echo "Error: [$error_no] $error_msg ";
echo "\n Now Script will end";
die();
}
// Setting set_error_handler
set_error_handler("myerror");
$a = 10;
$b = 0;
// Force the error
echo($a / $b);
?>
Not every function throws an exception when they fail. Many functions, especially ones that have been around for a long time, simply trigger PHP errors rather than exceptions.
To handle those, you would use a custom error handler:
https://www.php.net/manual/en/function.set-error-handler.php
So you could set up a custom error handler that would intercept those kinds of failures and throw them as exceptions. The whole point of that function is to do what you're trying to do - handle errors in a custom way.
I'm currently working on an open source personal project that provides a nice backend api for game developers. I'm in the early stages of development, but I plan to write tests as I go along, which is where I've hit a snag.
Through out the system when an error occurs such as incorrect api credentials or missing credentials, I throw a custom exception which stores a bit of extra data so that I can catch it and give a JSON encoded response.
The tests work fine for those thrown in my BaseController, but I also capture a few Laravel Exceptions so I can respond with my own, or at least, output JSON like below:
app/start/global.php
App::error(function(Exception $exception, $code) {
Log::error($exception);
});
App::missing(function(Exception $exception) {
return BaseController::error(
Config::get('response.method.code'),
Config::get('response.method.http'),
'Method not found'
);
});
App::error(function(Viper\Exception $exception) {
return BaseController::error(
$exception->getCode(),
$exception->getStatusCode(),
$exception->getMessage()
);
});
I'm using the try { } catch() { } approach as I need to check an extra value that isn't in the normal Exceptions.
public function testNoMethodGET() {
$config = Config::get('response.method');
try {
$this->call('GET', '/');
} catch(\Viper\Exception $e) {
$this->assertEquals($e->getCode(), $config['code']);
$this->assertEquals($e->getStatusCode(), $config['http']);
}
$this->fail('Exception not thrown');
}
This is all good and well, but I want to check a few things on the actual response, like for example, whether or not the json is valid, whether or not the response structure matches and whether or not the response values are correct.
If I set the return value of $this->call() to a variable, I'd be unable to access that variable within the catch block, so the question is this, how can I test the return value of $this->call() once the Exception has been caught?
According to Taylor Otwell:
"this can be solved by de-coupling your
test. You really want to test the handler and that the exception is
thrown totally separately anyways [sic] to isolate your tests. For
instance:
App::error(function(ErrorType $e)
{
App::make('ErrorTypeHandler')->handle($e);
});
Now you can write test cases for ErrorTypeHandler class separately
from the rest of your application. Then check that proper exceptions
are thrown by your app with #expectedException."
see How do you test your App::error implementations?
In your case, you already have isolated your error handler in BaseController::error(), so you can test the responses directly in separate unit tests, without the use of $this->call(). Instead, just call $response = BaseController::error() with the desired parameters and then inspect the response and apply relevant assertions.
I access a function in an included class Environment which can throw an Alert which needs to direct the users back to a page with some error information. What is the best way for me to reference the page so it can be used wherever I access the function from anywhere?
Is there any better way to do what I am trying to do?
public function checkEnvironment() {
try {
// If status is false
if (!$this->getStatus()) {
// Generate a new special exception with code
throw new Alert(6);
} else {
$connection = Gateway::checkInstance();
return $connection->getData('SELECT * FROM control_environment WHERE subdomain = ?', array($this->subdomain[0]));
}
} catch (Alert $alert) {
$_SESSION['error'] = $alert->getData();
if (!headers_sent()) {
header('Location: my/file/here.php');
exit;
}
}
}
You're badly abusing exceptions. There is absolutely no reason to put a single if statement in a try block, which can only throw one type of exception which is guaranteed to be caught immediately after that block. You've added nothing to your code but clutter, there is literally no advantage to doing this over simply doing an if/else with no exceptions/catching.
The point of exceptions is that you throw them up out of the current scope, to some place where they can actually be handled in a meaningful way.
Pick a real exception class, one that communicates something about the error that's occurred. Alert(6) doesn't tell anybody anything. Then, handle that (and probably many other) exceptions up above this, where you can be more sure that redirecting is the correct course of action. Your low-level database code shouldn't have any concept of browsers or http or redirection.
Your code also shouldn't have an else branch when the purpose of the if branch is to throw an exception. The else is redundant.
The whole function should look like this.
public function checkEnvironment() {
if (!$this->getStatus())
// Generate a new special exception with code
throw new StatusException;
$connection = Gateway::checkInstance();
return $connection->getData('SELECT * FROM control_environment WHERE subdomain = ?', array($this->subdomain[0]));
}
I'm using phpunit and the ecomdev module to unit test Magento. For a particular class the last code that needs to be tested is an exception on attempting to save a model in a try/catch. The only way I can see to get to the exception is alter the database temporarily. So I changed the table name which works, but then I have to name it back. If the test itself fails I'm in an inconsistent state.
I'd really like to get that code tested so the coverage is 100%. Otherwise I'll be wondering why it's 98% until I look at the code and remember the exception isn't tested.
I was trying to close the connection but I need it to log the exception. So I'm wondering if maybe there is something I can temporarily do to the model or resource model to cause the save to raise an exception. Something that would be reset on the next load.
One note - I can't see anyway that manipulating data will cause the exception. Again the only scenario I see causing an exception in production is if the database connection goes away.
Any ideas?
Edit:
Sample Code:
public function logStuff($stuff){
try{
Mage::getModel('my/stuff')
->setData('stuff', $stuff)
->save();
}catch(Exception $e){
Mage::helper('log/error')->logError(__METHOD__, "Could not save stuff: ". $e->getMessage());
}
}
To make test the exception catch, you need to replace your model instance with the mocked one.
It is very easy to achieve with EcomDev_PHPUnit extension:
$mockedStuff = $this->getModelMock('your/stuff', array('save'));
$mockedStuff->expects($this->once()) // How many times it is invoked
->method('save') // Wich method to mock
->will($this->returnCallback(function () {
throw new Exception('Some error text');
})); // Your exception
$this->replaceByMock('model', 'your/stuff', $mockedStuff);
Also you can evaluate your logging stuff by using mock as well.
$loggerMock = $this->getHelperMock('log/error', array('logError'));
$loggerMock->expects($this->once())
->method('logError')
->with('className::methodName', 'Could not save stuff: Some error text'); // Check that correct arguments passed
$this->replaceByMock('helper', 'log/error', $loggerMock);
Have fun with unit tests :)
I've been wondering why would I use Exceptions in my PHP. Let's take a look at a simple example:
class Worker
{
public function goToWork()
{
return $isInThatMood ?
// Okay, I'll do it.
true :
// In your dreams...
false;
}
}
$worker = new Worker;
if (!$worker->goToWork())
{
if (date('l',time()) == 'Sunday')
echo "Fine, you don't have to work on Sundays...";
else
echo "Get your a** back to work!";
}
else
echo "Good.";
Is there a reason for me to use Exceptions for that kind of code? Why? How would the code be built?
And what about code that may produce errors:
class FileOutputter
{
public function outputFile($file)
{
if (!file_exists($file))
return false;
return file_get_contents($file);
}
}
Why would I use Exceptions in the above case? I have a feeling that Exceptions help you to recognize the type of the problem, which occured, true?
So, am I using Exceptions appropriately in this code:
class FileOutputter
{
public function outputFile($file)
{
if (!file_exists($file))
return throw new Exception("File not found.",123);
try
{
$contents = file_get_contents($file);
}
catch (Exception $e)
{
return $e;
}
return $contents;
}
}
Or is that poor? Now the underlying code can do this:
$fo = new FileOutputter;
try
{
$fo->outputFile("File.extension");
}
catch (Exception $e)
{
// Something happened, we could either display the error/problem directly
echo $e->getMessage();
// Or use the info to make alternative execution flows
if ($e->getCode() == 123) // The one we specified earlier
// Do something else now, create "an exception"
}
Or am I completely lost here?
When should I use an exception?
You use an exception to indicate an exceptional condition; that is, something which prevents a method from fulfilling its contract, and which shouldn't have occurred at that level.
For example, you might have a method, Record::save(), which saves changes to a record into a database. If, for some reason, this can't be done (e.g. a database error occurs, or a data constraint is broken), then you could throw an exception to indicate failure.
How do I create custom exceptions?
Exceptions are usually named such that they indicate the nature of the error, for example, DatabaseException. You can subclass Exception to create custom-named exceptions in this manner, e.g.
class DatabaseException extends Exception {}
(Of course, you could take advantage of inheritance to give this exception some additional diagnostic information, such as connection details or a database error code, for example.)
When shouldn't I use an exception?
Consider a further example; a method which checks for file existence. This should probably not throw an exception if the file doesn't exist, since the purpose of the method was to perform said check. However, a method which opens a file and performs some processing could throw an exception, since the file was expected to exist, etc.
Initially, it's not always clear when something is and isn't exceptional. Like most things, experience will teach you, over time, when you should and shouldn't throw an exception.
Why use exceptions instead of returning special error codes, etc?
The useful thing about exceptions is that they immediately leap out of the current method and head up the call stack until they're caught and handled, which means you can move error-handling logic higher up, although ideally, not too high.
By using a clear mechanism to deal with failure cases, you automatically kick off the error handling code when something bad happens, which means you can avoid dealing with all sorts of magic sentinel values which have to be checked, or worse, a global error flag to distinguish between a bunch of different possibilities.
I'm not a PHP programmer, but this looks similar to C#.
Typically you'd want to throw errors if it is a point of no return. Then you would be able to log something to show that the impossible happened.
If you can tell that the file doesn't exist then you could just say that. No real need in my mind to also throw an exception.
Now if the file was found and you are processing it, and say only half the file was uploaded and you had no way of telling that without an exception, then it'd be nice to have around.
I would say it's a good design practice to avoid the catch all exceptions "catch (Exception $e)" and design by contract instead, just like you seem to be doing in the prior example. I would at first be more specific with the type of exception being thrown and then work from there if needed. Otherwise, stay away from the try->catch and exceptions.
In no way can you assume that a file exists just because you called file_exists()! The function file_exists doesn't open the file, so the file can potentially be deleted or renamed or moved at any time!
class FileOutputter
{
public function outputFile($file)
{
if (!file_exists($file))
return false;
///<--- file may be deleted right here without you knowing it
return file_get_contents($file);//<-- then this will throw an error
//if you don't catch it, you're program may halt.
}
}
I believe this it better:
class FileOutputter
{
public function outputFile($file)
{
try{
if (!file_exists($file))
return false;
return file_get_contents($file);
}catch(Exception e){
check_what_went_wrong_and_go_to_plan_B();
}
}
}
(Edit: And it's probably even better to actually try to open the file from the beginning. If you succeed then you have a 'lock' on the file and it won't just disappear. If not, then catch the exception and see what went wrong.
Then again, you might feel that this level of reduncancy is just silly. In that case I don't think you need to worry about try/catch at all :)
Just a note really, your code for file outputter is invalid, since file_get_contents($file)
does not throw an exception. It will however raise a warning if the file doesn't exist, or can't be accessed for some reason. Additionally, you are returning an exception from outputFile, when you should probably be just letting the error propagate up the call stack.
However, you can register the error handler in php to throw exceptions when an error occurs:
function exception_error_handler($errno, $errstr, $errfile, $errline ) {
throw new ErrorException($errstr, 0, $errno, $errfile, $errline);
}
set_error_handler("exception_error_handler");
That way, any standard function calls that cause an error will throw an exception.
So, I would change FileOutputter to this (with that snippet above added):
class FileOutputter
{
public function outputFile($file)
{
if (!file_exists($file))
throw new Exception("File not found.",123);
return file_get_contents($file);
}
}
The calling code is then basically the same.
Basically rule is not to return an Exception when an error occurs - you can catch it if you want, and throw a custom exception, but let the exception go up the call stack until you want to use it.