Is there any way to use parameterized unit tests, similar to what you can achieve in .Net using NUnit framework.
[TestCase(12, 3, 4)]
[TestCase(12, 2, 6)]
[TestCase(12, 4, 3)]
public void DivideTest(int expectedResult, int a, int b)
{
Assert.AreEqual(expectedResult, a / b);
}
Using this kind of tests (vs non-parameterized ones) can give you bigger back for buck by allowing you to avoid writing series of almost identical unit tests differing only by parameter values.
I am looking for either XCTest-based solution or some other means to achieve it. Optimal solution should report each test case (parameter set) as a separate unit test in Xcode, so is it clear whether all or only some of the tests cases failed.
The best way to use parametrized is using the XCTestCase subclass's property defaultTestSuite
. A clearly example with devision is the next:
import XCTest
class ParameterizedExampleTests: XCTestCase {
//properties to save the test cases
private var array: [Float]? = nil
private var expectedResult: Float? = nil
// This makes the magic: defaultTestSuite has the set of all the test methods in the current runtime
// so here we will create objects of ParameterizedExampleTests to call all the class' tests methodos
// with differents values to test
override open class var defaultTestSuite: XCTestSuite {
let testSuite = XCTestSuite(name: NSStringFromClass(self))
addTestsWithArray([12, 3], expectedResult: 4, toTestSuite: testSuite)
addTestsWithArray([12, 2], expectedResult: 6, toTestSuite: testSuite)
addTestsWithArray([12, 4], expectedResult: 3, toTestSuite: testSuite)
return testSuite
}
// This is just to create the new ParameterizedExampleTests instance to add it into testSuite
private class func addTestsWithArray(_ array: [Float], expectedResult: Float, toTestSuite testSuite: XCTestSuite) {
testInvocations.forEach { invocation in
let testCase = ParameterizedExampleTests(invocation: invocation)
testCase.array = array
testCase.expectedResult = expectedResult
testSuite.addTest(testCase)
}
}
// Normally this function is into production code (e.g. class, struct, etc).
func division(a: Float, b: Float) -> Float {
return a/b
}
func testDivision() {
XCTAssertEqual(self.expectedResult, division(a: array?[0] ?? 0, b: array?[1] ?? 0))
}
}