Writing parameterized tests can be a powerful technique to test your code with different input values. It allows you to test your code against a range of inputs and verify that it behaves correctly in various scenarios. In this blog post, we will explore how to write parameterized tests using the Spock testing framework in Java.

Spock is a testing and specification framework that offers a fluent, expressive, and easy-to-read syntax for writing tests. It provides built-in support for parameterized testing through its @Unroll annotation, which allows you to generate multiple test cases from a single test definition.

Here’s an example of how to write a parameterized test using Spock:

import spock.lang.Specification
import spock.lang.Unroll

class ParameterizedTestExample extends Specification {

    @Unroll
    def "test adding #a and #b should result in #expectedSum"() {
        given:
        def calculator = new Calculator()

        when:
        def sum = calculator.add(a, b)

        then:
        sum == expectedSum

        where:
        a     | b     | expectedSum
        1     | 2     | 3
        5     | 10    | 15
        -5    | -5    | -10
    }
}

In the code snippet above, we define a parameterized test method using the @Unroll annotation. This annotation allows us to specify the parameter names (a, b, expectedSum) in the test method name. The test method will be executed multiple times, once for each set of parameters provided in the where block.

Inside the test method, we initialize a Calculator object, perform the desired operation (in this case, addition), and assert that the result matches the expected sum.

The where block provides the input values for the test cases. Each row in the where block represents a set of parameters that will be passed to the test method. In the example above, we test three cases: (1, 2, 3), (5, 10, 15), and (-5, -5, -10).

By running this test, Spock will automatically generate individual test cases for each set of parameters, making it easy to see which inputs pass or fail.

To run the test, you can use your preferred build tool (e.g., Gradle or Maven) or execute it directly from your IDE. Spock integrates seamlessly with popular Java IDEs, providing a smooth testing experience.

In conclusion, writing parameterized tests with Spock simplifies testing multiple scenarios and ensures your code behaves correctly across different input values. The @Unroll annotation in Spock makes it easy to generate and execute parameterized tests, making your test suite more robust and thorough.

#Java #Spock