AssertionsTestingExample

This library is deprecated. You can use https://github.com/mattgallagher/CwlPreconditionTesting instead.

Finally, you can achieve 100% coverage. Previously, you couldn't because you cannot test assert, assertionFailure, precondition, preconditionFailure and fatalError. But now with every easy steps you can test them.

This is an example app to show you how to do it. When you test command + U the app. You will find many test cases fail. This is intentional, to show that expectAssert for example fails the test case with a proper error message when the assert function is not called.

When you go to the coverage, you finally can see that we have 100% coverage.

HOW TO USE

1. Drop ProgrammerAssertions.swift to the target of your app or framework under test. Just besides your source code.
2. Drop XCTestCase+ProgrammerAssertions.swift to your test target. Just besides your test cases.
3. Use assert, assertionFailure, precondition, preconditionFailure and fatalError normally as you always do.
4. Unit test them with the new methods expectAssert, expectAssertionFailure, expectPrecondition, expectPreconditionFailure and expectFatalError.

For example: If you have a function that does a division like the following:

func divideFatalError(x: Float, by y: Float) -> Float {

    guard y != 0 else {
        fatalError("Zero division")
    }
    
    return x / y
}

You can test the 0 division with the following code.

func testFatalCorrectMessage() {
    expectFatalError("Zero division") {
        divideFatalError(1, by: 0)
    }
}

Or if you don't want to test the message, you simply do.

func testFatalErrorNoMessage() {
    expectFatalError() {
        divideFatalError(1, by: 0)
    }
}

Attributions

Thanks to nschum and Ken Ko they have the credit for creating these reusable files. I just added very few stuff.

Author

Mohamed Afifi, [email protected]

License

AssertionsTestingExample is available under the MIT license. See the LICENSE file for more info.