Testing Your Application
With CFWheels, writing automated tests for your application is part of the development lifecycle itself, and running the tests is as simple as clicking a link.
Why Test?
At some point, your code is going to break. Upgrades, feature enhancements, and bug fixes are all part of the development lifecycle. Quite often with deadlines, you don't have the time to test the functionality of your entire application with every change you make.
The problem is that today's fix could be tomorrow's bug. What if there were an automated way of checking if that change you're making is going to break something? That's where writing tests for your application can be invaluable.
In the past, writing test against your application meant downloading, configuring and learning a completely separate framework. This often caused more headaches than it was worth and was the reason why most developers didn't bother writing tests. With CFWheels, we've included a small and very simple testing framework based on RocketUnit to help address just this issue.
The Test Framework
Like everything else in CFWheels, the testing framework is very simple, yet powerful. You don't need to remember a hundred different functions because CFWheels' testing framework contains only a handful.
Conventions
In order to run tests against your application, all tests must reside in the tests
directory off the root of your CFWheels application, or within a subdirectory thereof.
When you run the tests for your application, CFWheels recursively scans your application's tests
directory for valid tests. Whilst you have freedom to organize your subdirectories, tests and supporting files any way you see fit, we would recommend using the directory structure below as a guide:
What are these directories for?
The "functions" directory might contain test packages that cover model methods, global or view helper functions.
The "requests" directory might contain test packages that cover controller actions and the output that they generate (views).
Any components that will contain tests must extend the wheels.Test
component:
If the testing framework sees that a component does not extend wheels.Test
, that component will be skipped. This lets you create and store any mock components that you might want to use with your tests and keep everything together.
Any test methods must begin their name with "test":
If a method does not begin with test
, it is ignored and skipped. This lets you create as many helper methods for your testing components as you want.
Do not var
-scope any variables used in your tests. In order for the testing framework to access the variables within the tests that you're writing, all variables need to be within the component's variables
scope. The easy way to do this is to just not var
variables within your tests, and your CFML engine will automatically assign these variables into the variables
scope of the component for you. You'll see this in the examples below.
Setup & Teardown
When writing a group of tests, it's common for there to be some duplicate code, global configuration, and/or cleanup needs that need to be run before or after each test. In order to keep things DRY (Don't Repeat Yourself), the testing framework offers 2 special methods that you can optionally use to handle such configuration.
setup()
: Used to initialize or override any variables or execute any code that needs to be run before each test.
teardown()
: Used to clean up any variables or execute any code that needs to be ran after each test.
Example:
Evaluation
assert()
: This is the main method that you will be using when developing tests. To use, all you have to do is provide a quoted expression. The power of this is that ANY 'truthy' expression can be used.
An example test that checks that two values equal each other:
An example test that checks that the first value is less then the second value:
You get the idea since you've used these kinds of expressions a thousand times. If you think of the assert()
command as another way of using evaluate()
, it will all make sense. Remember that you can use any expression that evaluates to a boolean value, so if you can write assertions against structures, arrays, objects, you name it, you can test it!
An example test that checks that a key exists in a structure:
raised()
: Used when you want to test that an exception will be thrown. raised()
will raise and catch the exception and return to you the exception type (think cfcatch.type
). Just like assert()
, raised()
takes a quoted expression as its argument.
An example of raising the Wheels.TableNotFound
error when you specify an invalid model name:
Debugging
debug()
: Will display its output after the test result so you can examine an expression more closely.
expression
(string) - a quoted expression to display
display
(boolean) - whether or not to display the output
TIP
Overloaded arguments will be passed to the internal cfdump
attributeCollection
Testing Your Models
The first part of your application that you are going to want to test against are your models because this is where all the business logic of your application lives. Suppose that we have the following model:
As you can see from the code above, our model has a beforeSave
callback that runs whenever we save a user object. Let's get started writing some tests against this model to make sure that our callback works properly.
First, create a test component called /tests/models/TestUserModel.cfc
, and in the setup
function, create an instance of the model that we can use in each test that we write. We will also create a structure containing some default properties for the model.
As you can see, we invoke our model by using the model()
method just like you would normally do in your controllers.
The first thing we do is add a simple test to make sure that our custom model validation works.
Now that we have tests to make sure that our model validations work, it's time to make sure that the callback works as expected when a valid model is created.
Testing Your Controllers
The next part of our application that we need to test is our controller. Below is what a typical controller for our user model would contain for creating and displaying a list of users:
Notice the return
in the create
action in the redirectTo()
method? The reason for this is quite simple, under the covers, when you call redirectTo()
, CFWheels is using cflocation
. As we all know, there is no way to intercept or stop a cflocation
from happening. This can cause quite a number of problems when testing out a controller because you would never be able to get back any information about the redirection.
To work around this, the CFWheels test framework will "delay" the execution of a redirect until after the controller has finished processing. This allows CFWheels to gather and present some information to you about what redirection will occur.
The drawback to this technique is that the controller will continue processing and as such we need to explicitly exit out of the controller action on our own, thus the reason why we use return
.
Let's create a test package called /tests/controllers/TestUsersController.cfc
to test that the create
action works as expected:
Notice that a lot more goes into testing a controller than a model. The first step is setting up the params
that will need to be passed to the controller. We then pass the 'params' to the processRequest()
function which returns a structure containing a bunch of useful information.
We use this information to make sure that the controller redirected the visitor to the index
action once the action was completed.
Note: processRequest()
is only for use within the test framework.
Below are some examples of how a controller can be tested:
Testing Controller Variables
If you want to test a variable that's being set on a controller you can make use of the this
scope. This way it's available from outside the controller, which makes it testable.
If you think that's too "ugly", you can instead make a public function on the controller that returns the value and then call that from your tests.
Testing Partials
You may at some point want to test a partial (usually called via includePartial()
) outside of a request. You'll notice that if you just try and call includePartial()
from within the test suite, it won't work. Thankfully there's a fairly easy technique you can use by calling a "fake" or "dummy" controller.
Testing Your Views
Next we will look at testing the view layer. Below is the code for new.cfm
, which is the view file for the controller's new
action:
Testing the view layer is very similar to testing controllers, we will setup a params structure to pass to the processRequest()
function which will return (among other things) the generated view output.
Once we have this output, we can then search through it to make sure that whatever we wanted the view to display is presented to our visitor. In the test below, we are simply checking for the heading.
Testing Your Application Helpers
Next up is testing global helper functions. Below is a simple function that removes spaces from a string.
Testing these helpers is fairly straightforward. All we need to do is compare the function's return value against a value that we expect, using the assert()
function.
Testing Your View Helpers
Testing your view helpers are very similar to testing application helpers except we need to explicitly include the helpers in the setup()
function so our view functions are available to the test framework.
Below is a simple function that returns a string wrapped in h1
tags.
And in our view test package:
Testing Plugins
Testing plugins requires slightly different approaches depending on the mixin
attribute defined in the plugin's main component.
Below is a simple plugin called timeAgo
that extends CFWheels' timeAgoInWords
view helper by appending "ago" to the function's return value. Take note of the mixin="controller"
argument as this will play a part in how we test the plugin.
In order to test our plugin, we'll need to do a little setup. Our plugin's tests will reside in a directory within our plugin package named tests
. We'll also need a directory to keep test assets, in this case a dummy controller that we will need to instantiate in out test's setup()
function.
The /plugins/timeago/tests/assets/controllers/Dummy.cfc
controller contains the bare minimum for a controller.
Firstly, in our /plugins/timeago/tests/TestTimeAgo.cfc
we'll need to copy the application scope so that we can change some of CFWheels' internal paths. Fear not, we'll reinstate any changes after the tests have finished executing using the teardown
function. so that if you're running your tests on your local development machine, your application will continue to function as expected after you're done testing.
Once the setup is done, we simply execute the plugin functions and assert that the return values are what we expect.
If your plugin is uses mixin="model"
, you will need to create and instantiate a dummy model component.
Running Your Tests
Down in the debug area of your CFWheels application (that grey area at the bottom of the page), you will notice a some links for running tests for the following areas:
Run Tests Runs all tests that you have created for your application. You should run these tests before deploying your application.
View Tests Shows a list of all your test packages with links to run individual packages or single tests.
Framework Tests If you have cloned the CFWheels repository, you will also see a link to run the core framework unit tests.
Plugin Tests If a plugin has a /tests
directory, you will also see a link to run the plugin's tests.
The test URL will look something like this:
/index.cfm?controller=wheels&action=wheels&view=tests&type=app
Running an individual package:
/index.cfm?controller=wheels&action=wheels&view=tests&type=app&package=controllers
Running a single test:
/index.cfm?controller=wheels&action=wheels&view=tests&type=app&package=controllers&test=testCaseOne
These URLs are useful should you want an external system to run your tests.
Test Results Format
CFWheels can return your test results in either HTML, JUnit or JSON formats, simply by using the format
url parameter. Eg: format=junit
Additional Techniques
Once you're comfortable with the concepts thus far, there are a few more functions available which can be used to modify the behavior of your test suite.
beforeAll()
- Runs once before the test suite has run. Here is where you might populate a test database or set suite-specific application variables*.
afterAll()
- Runs once after the test suite has finished.
packageSetup()
- Used in a test package, similar to setup()
but only runs once before a package's first test case. Here is where you might set variables that are common to all the tests in a CFC.
packageTeardown()
- Used in a test package, similar to teardown()
but only runs once after a package's last test case. Here is where you might cleanup files, database rows created by test cases or revert application variables in a CFC.
A typical test request lifecycle will look something like this:
Test.cfc -beforeAll()
Foo.cfc - packageSetup()
Foo.cfc - setup()
Foo.cfc - testCaseOne()
Foo.cfc - teardown()
Foo.cfc - setup()
Foo.cfc - testCaseTwo()
Foo.cfc - teardown()
Foo.cfc - packageTeardown()
Bar.cfc - packageSetup()
Bar.cfc - setup()
Bar.cfc - testCaseThree()
Bar.cfc - teardown()
Bar.cfc - packageTeardown()
Test.cfc - afterAll()
In order to use beforeAll()
and afterAll()
, you'll need to make a few small changes to your test suite. Firstly, create a Test.cfc
in the root of your /tests/
directory. This is where you'll define your beforeAll()
and afterAll()
functions and it should look something like this:
For your test packages to inherit these functions, you'll need to change the extends
attribute in your
test packages to extends="tests.Test"
. This enables the CFWheels test framework to run your functions.
Since we've implemented the new Test.cfc
component, we now have global setup()
and teardown()
functions will run respectively before and after every test case. If we want to prevent these from running in a particular package, we simply override the global functions like this:
If we want to run the global function AND some package-specific setup & teardown code, here's how achieve that:
Whilst best practice recommends that tests should be kept as simple and readable as possible, sometimes moving commonly used code into test suite helpers can greatly improve the simplicity of your tests.
Some examples may include, serializing complex values for use in assert()
or grouping multiple assertions together. Whatever your requirements, there are a number of ways to use test helpers.
Put your helper functions in your
/tests/Test.cfc
. These will be available to any package that extends this component. Be mindful of functions you put in here, as it's easy to create naming collisions.If you've arranged your tests into subdirectories, you can create a
helpers.cfm
file in any given directory and simply include it in the package.Put package-specific helper functions in the same package as the tests that use it. These will only be available to the tests in that package. To ensure that these test helpers are not run as tests, use a function name that doesn't start with "test_". Eg:
$simplify()
Overloading application vars.. CFWheels will revert the application scope after all tests have completed.
Caveat: The test suite request must complete without uncaught exceptions. If an uncaught exception occurs, the application scope may stay 'dirty', so it's recommended to reload the application by adding reload=true
param to your url whilst developing your test packages.
Learn By Example: CFWheels Core
The CFWheels core uses this test framework for its unit test suite and contains a wealth of useful examples. They can all be found in the tests
folder of the CFWheels git repo.
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