Welcome to the OCMock documentation page! Here you will find all the information you need to get started with OCMock, a powerful mocking and stubbing framework for Objective-C.
Installation
To install OCMock, you can use CocoaPods. Just add the following line to your Podfile:
pod 'OCMock', '~> 3.7'
Run pod install
to fetch and install OCMock. Then, make sure to import the OCMock header file wherever you want to use it:
#import <OCMock.h>
Getting Started
OCMock makes it easy to create mocks and stubs for your Objective-C classes when writing unit tests. Here’s a quick guide to get you started:
Creating Mock Objects
You can create a mock object by using the OCMockObject
class and passing your class as a parameter to the mockForClass:
method. For example:
id mockObject = [OCMockObject mockForClass:[MyClass class]];
This creates a mock object for the MyClass
class.
If you want to partially mock a class instead, you can use the partialMockForObject:
method:
id partialMockObject = [OCMockObject partialMockForObject:myObject];
This creates a partial mock for the myObject
instance.
Setting Up Expectations
Once you have a mock object, you can set up expectations for method calls using the expect
method. For example:
[[mockObject expect] myMethod];
This sets an expectation that the myMethod
method will be called on the mock object.
Verifying Expectations
After you have set up expectations, you can verify that they have been met using the verify
method. For example:
[mockObject verify];
This will throw an exception if any expectations were not met.
Stubbing Methods
You can also stub methods on mock objects to define their behavior using the andReturn:
method. For example:
[[[mockObject stub] andReturn:@"hello"] myMethod];
This stubs the myMethod
method and makes it return "hello"
.
Cleaning Up
Don’t forget to clean up after each test by calling the stopMocking
method on your mock objects. This releases any resources held by the mock objects. For example:
[mockObject stopMocking];
It’s a good practice to do this in the tearDown
method of your test case.
Advanced Features
OCMock provides several advanced features to help you write comprehensive unit tests. Here are a few key features:
Mocking Class Methods
You can mock class methods by using the mockForClass:
method and instead passing the metaclass of the class you want to mock. For example:
id mockObject = [OCMockObject mockForClass:object_getClass([MyClass class])];
This creates a mock object for the metaclass of the MyClass
class.
Setting Up Constraints
OCMock allows you to set up constraints for method arguments. You can use the with:
keyword to define constraints. For example:
BOOL isEven = YES;
[[mockObject expect] myMethodWithNumber: [OCMArg checkWithBlock:^(NSNumber *number) {
return [number intValue] % 2 == 0;
}]];
This sets an expectation that the myMethodWithNumber:
method will be called with an even number argument.
Ordering Expectations
You can specify the order in which you expect methods to be called by using the andDo:
method. For example:
[[[mockObject expect] myMethod1] andDo:^(NSInvocation *invocation) {
[[mockObject2 expect] myMethod2];
}];
This sets an expectation that myMethod1
will be called first and then myMethod2
on mockObject2
.
Additional Resources
For more information about OCMock and its features, check out the following resources: