@CsvAutoSource

The @CsvAutoSource annotation merges the features of @CsvSource and @AutoSource, providing you with the flexibility to specify CSV-formatted arguments for some parameters while generating random values for the remaining ones.

How to Use

To use @CsvAutoSource, annotate your test method with it and provide CSV-formatted input values for the initial set of parameters. The remaining parameters will be populated with automatically generated values.

Here's a simple example:

Java

@ParameterizedTest
@CsvAutoSource({"16, foo"})
void testMethod(int arg1, String arg2, String arg3) {
    assertEquals(16, arg1);
    assertEquals("foo", arg2);
    assertNotEquals(arg2, arg3);
}

Kotlin

@ParameterizedTest
@CsvAutoSource("16, foo")
fun testMethod(arg1: Int, arg2: String, arg3: String) {
    assertEquals(16, arg1)
    assertEquals("foo", arg2)
    assertNotEquals(arg2, arg3)
}

In this example, arg1 is set to 16 and arg2 is set to "foo" based on the provided CSV input. Meanwhile, arg3 will be assigned a randomly generated value. The test verifies that arg3 is different from arg2.

Compatibility with @Freeze

Just like @ValueAutoSource, @CsvAutoSource is fully compatible with the @Freeze annotation, allowing you to lock in values for specific parameters while also defining others via CSV.

Here's how they can work together:

Java

@AllArgsConstructor
@Getter
public class ValueContainer {
    private final String value;
}

Kotlin

class ValueContainer(val value: String)

Java

@ParameterizedTest
@CsvAutoSource({"16, foo"})
void testMethod(int arg1, @Freeze String arg2, ValueContainer arg3) {
    assertEquals("foo", arg3.getValue());
}

Kotlin

@ParameterizedTest
@CsvAutoSource("16, foo")
fun testMethod(arg1: Int, @Freeze arg2: String, arg3: ValueContainer) {
    assertEquals("foo", arg3.value)
}

Benefits

1. Dual Control: The ability to specify values via CSV for some parameters while allowing automatic random generation for others provides a high level of control over your test data.
2. Streamlined Testing: By allowing both manual and automated data input, @CsvAutoSource simplifies the setup of complex tests.
3. Flexible and Comprehensive: This feature offers you the flexibility to cover a broader range of test scenarios by mixing pre-defined and random values.

The @CsvAutoSource annotation is another versatile tool in your testing suite, adding both precision and coverage to your parameterized tests.