Junit5 ‐ Parameterized Tests

About The test

• We can use this type of test to run multiple tests from a single test case with different inputs as params that change instead of writing a separate new test for each param.
• Three types of parameterized test are present
  • valueSource
  • csvFileSource
  • csvSource

Code

Class in test

class ShoppingCart {

    private val items = mutableListOf<Product>()

    fun addProduct(product: Product, quantity: Int) {
        if(quantity < 0) {
            throw IllegalArgumentException("Quantity can't be negative")
        }
        repeat(quantity) {
            items.add(product)
        }
    }

    fun getTotalCost(): Double {
        return items.sumOf { it.price }
    }
}

Our test case -----> ValueSource

• The below test will run twice and each time a new value is passed

@ParameterizedTest
    @ValueSource(
        ints = [2,2]
    )
    fun `Add multiple products, total price sum is correct with parameterized test way`(
        quantityParam : Int
    ){
        val productOne = Product(id = 1, name = "Product-1", price = 1.0)
        cart.addProduct(productOne,quantityParam)
        assertThat(cart.getTotalCost()).isEqualTo(2.0)
    }
}

Our test case -----> csvSource

• Here we can pass kind of collection of inputs as parameters
• Here three tests are conducted and all will be passed

    @ParameterizedTest
    @CsvSource(
        "2,2.0",
        "3,3,0",
        "4,4,0"
    )
    fun `Add multiple products, total price sum is correct with parameterised test way`(
        inputParam : Int, expectedParam : Double
    ){
        val productOne = Product(id = 1, name = "Product-1", price = 1.0)
        cart.addProduct(productOne,inputParam)
        assertThat(cart.getTotalCost()).isEqualTo(expectedParam)
    }