5.1 @ParameterizedTest annotation
Sometimes you just want to call the test multiple times with different parameters: different values, different input parameters, different usernames. JUnit aims to make your life easier, so for this case it has such a thing as parameterized tests.
To use parameterized tests, you need to add one more dependency to your pom.xml
:
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-params</artifactId>
<version>5.8.2</version>
<scope>test</scope>
</dependency>
Then we can consider an example:
@ParameterizedTest
@ValueSource(ints = { 1, 2, 3 })
void testMethod(int argument) {
//test code
}
@ParameterizedTest
@ValueSource(ints = { 1, 2, 3 })
void testMethodWithAutoboxing(Integer argument) {
//test code
}
Each test method will be called 3 times, and each time it is called, another parameter will be passed to it. Values are set using another annotation - @ValueSource . But more needs to be said about it.
5.2 @ValueSource annotation
The @ValueSource annotation is great for working with primitives and literals. Just list the parameter values separated by commas and the test will be called once for each value.
@ParameterizedTest
@ValueSource(ints = { 1, 2, 3 })
void testMethodWithAutoboxing(Integer argument) {
//test code
}
But there is also a minus - this annotation does not support null, so you will need to use a special crutch for it - @NullSource . It looks like this:
@ParameterizedTest
@NullSource
void testMethodNullSource(Integer argument) {
assertTrue(argument == null);
}
5.3 @EnumSource annotation
There is also a special annotation @EnumSource , which passes all the values of a specific Enum to the method. Its application looks like this:
enum Direction {
EAST, WEST, NORTH, SOUTH
}
@ParameterizedTest
@EnumSource(Direction.class)
void testWithEnumSource(Direction d) {
assertNotNull(d);
}
5.4 @MethodSource annotation
But how to pass objects as parameters? Especially if they have a complex construction algorithm. To do this, you can simply specify a special helper method that will return a list (Stream) of such values.
Example:
@ParameterizedTest
@MethodSource("argsProviderFactory")
void testWithMethodSource(String argument) {
assertNotNull(argument);
}
static Stream<String> argsProviderFactory() {
return Stream.of("one", "two", "three");
}
Parameterized Tests with Multiple Arguments
Of course, you have already wondered what to do if you want to pass several parameters to the method. There is a very cool @CSVSource annotation for this . It allows you to list the values of the method parameters simply separated by commas.
Example:
@ParameterizedTest
@CsvSource({
"alex, 30, Programmer, Working",
"brian, 35, Tester, Working",
"charles, 40, manager, kicks"
})
void testWithCsvSource(String name, int age, String occupation, String status) {
//method code
}
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