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java.lang.Objectorg.junit.runner.Runner
org.junit.runners.ParentRunner<Runner>
org.junit.runners.Suite
org.junit.runners.Parameterized
public class Parameterized
The custom runner Parameterized implements parameterized tests.
When running a parameterized test class, instances are created for the
cross-product of the test methods and the test data elements.
For example, to test the + operator, write:
@RunWith(Parameterized.class)
public class AdditionTest {
@Parameters(name = "{index}: {0} + {1} = {2}")
public static Iterable<Object[]> data() {
return Arrays.asList(new Object[][] { { 0, 0, 0 }, { 1, 1, 2 },
{ 3, 2, 5 }, { 4, 3, 7 } });
}
private int firstSummand;
private int secondSummand;
private int sum;
public AdditionTest(int firstSummand, int secondSummand, int sum) {
this.firstSummand = firstSummand;
this.secondSummand = secondSummand;
this.sum = sum;
}
@Test
public void test() {
assertEquals(sum, firstSummand + secondSummand);
}
}
Each instance of AdditionTest will be constructed using the
three-argument constructor and the data values in the
@Parameters method.
In order that you can easily identify the individual tests, you may provide a
name for the @Parameters annotation. This name is allowed
to contain placeholders, which are replaced at runtime. The placeholders are
In the example given above, the Parameterized runner creates
names like [2: 3 + 2 = 5]. If you don't use the name parameter,
then the current parameter index is used as name.
You can also write:
@RunWith(Parameterized.class)
public class AdditionTest {
@Parameters(name = "{index}: {0} + {1} = {2}")
public static Iterable<Object[]> data() {
return Arrays.asList(new Object[][] { { 0, 0, 0 }, { 1, 1, 2 },
{ 3, 2, 5 }, { 4, 3, 7 } });
}
@Parameter(0)
public int firstSummand;
@Parameter(1)
public int secondSummand;
@Parameter(2)
public int sum;
@Test
public void test() {
assertEquals(sum, firstSummand + secondSummand);
}
}
Each instance of AdditionTest will be constructed with the default constructor
and fields annotated by @Parameter will be initialized
with the data values in the @Parameters method.
The parameters can be provided as an array, too:
@Parameters
public static Object[][] data() {
return new Object[][] { { 0, 0, 0 }, { 1, 1, 2 }, { 3, 2, 5 }, { 4, 3, 7 } } };
}
If your test needs a single parameter only, you don't have to wrap it with an
array. Instead you can provide an Iterable or an array of
objects.
@Parameters
public static Iterable<? extends Object> data() {
return Arrays.asList("first test", "second test");
}
or
@Parameters
public static Object[] data() {
return new Object[] { "first test", "second test" };
}
If your test needs to perform some preparation or cleanup based on the
parameters, this can be done by adding public static methods annotated with
@BeforeParam/@AfterParam. Such methods should either have no
parameters or the same parameters as the test.
@BeforeParam
public static void beforeTestsForParameter(String onlyParameter) {
System.out.println("Testing " + onlyParameter);
}
By default the Parameterized runner creates a slightly modified
BlockJUnit4ClassRunner for each set of parameters. You can build an
own Parameterized runner that creates another runner for each set of
parameters. Therefore you have to build a ParametersRunnerFactory
that creates a runner for each TestWithParameters. (
TestWithParameters are bundling the parameters and the test name.)
The factory must have a public zero-arg constructor.
public class YourRunnerFactory implements ParametersRunnerFactory {
public Runner createRunnerForTestWithParameters(TestWithParameters test)
throws InitializationError {
return YourRunner(test);
}
}
Use the Parameterized.UseParametersRunnerFactory to tell the Parameterized
runner that it should use your factory.
@RunWith(Parameterized.class)
@UseParametersRunnerFactory(YourRunnerFactory.class)
public class YourTest {
...
}
With assumptions you can dynamically skip tests.
Assumptions are also supported by the @Parameters method.
Creating parameters is stopped when the assumption fails and none of the
tests in the test class is executed. JUnit reports a
single assumption failure for the
whole test class in this case.
@Parameters
public static Iterable<? extends Object> data() {
String os = System.getProperty("os.name").toLowerCase()
Assume.assumeTrue(os.contains("win"));
return Arrays.asList("first test", "second test");
}
| Nested Class Summary | |
|---|---|
static interface |
Parameterized.AfterParam
Annotation for public static void methods which should be executed after
evaluating tests with particular parameters. |
static interface |
Parameterized.BeforeParam
Annotation for public static void methods which should be executed before
evaluating tests with particular parameters. |
static interface |
Parameterized.Parameter
Annotation for fields of the test class which will be initialized by the method annotated by Parameters. |
static interface |
Parameterized.Parameters
Annotation for a method which provides parameters to be injected into the test class constructor by Parameterized. |
static interface |
Parameterized.UseParametersRunnerFactory
Add this annotation to your test class if you want to generate a special runner. |
| Nested classes/interfaces inherited from class org.junit.runners.Suite |
|---|
Suite.SuiteClasses |
| Constructor Summary | |
|---|---|
Parameterized(Class<?> klass)
Only called reflectively. |
|
| Method Summary |
|---|
| Methods inherited from class org.junit.runners.Suite |
|---|
describeChild, emptySuite, getChildren, runChild |
| Methods inherited from class org.junit.runners.ParentRunner |
|---|
childrenInvoker, classBlock, classRules, collectInitializationErrors, createTestClass, filter, getDescription, getName, getRunnerAnnotations, getTestClass, isIgnored, order, run, runLeaf, setScheduler, sort, validatePublicVoidNoArgMethods, withAfterClasses, withBeforeClasses, withInterruptIsolation |
| Methods inherited from class org.junit.runner.Runner |
|---|
testCount |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Constructor Detail |
|---|
public Parameterized(Class<?> klass)
throws Throwable
Throwable
|
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