Package org.junit.platform.launcher

Interface Launcher

@API(status=STABLE,
     since="1.0")
public interface Launcher

The Launcher API is the main entry point for client code that wishes to discover and execute tests using one or more test engines.

Implementations of this interface are responsible for determining the set of test engines to delegate to at runtime and for ensuring that each test engine has an ID that is unique among the registered test engines. For example, the default implementation returned by LauncherFactory.create() dynamically discovers test engines via Java's ServiceLoader mechanism.

Test discovery and execution require a LauncherDiscoveryRequest that is passed to all registered engines. Each engine decides which tests it can discover and execute according to the supplied request.

Prior to executing tests, clients of this interface should register one or more TestExecutionListener instances in order to get feedback about the progress and results of test execution. Listeners will be notified of events in the order in which they were registered. The default implementation returned by LauncherFactory.create() dynamically discovers test execution listeners via Java's ServiceLoader mechanism.

Since:

1.0

See Also:

LauncherDiscoveryRequest, TestPlan, TestExecutionListener, LauncherFactory, TestEngine

Method Summary

Modifier and Type	Method	Description
TestPlan	discover(LauncherDiscoveryRequest launcherDiscoveryRequest)	Discover tests and build a TestPlan according to the supplied LauncherDiscoveryRequest by querying all registered engines and collecting their results.
void	execute(LauncherDiscoveryRequest launcherDiscoveryRequest, TestExecutionListener... listeners)	Execute a TestPlan which is built according to the supplied LauncherDiscoveryRequest by querying all registered engines and collecting their results, and notify registered listeners about the progress and results of the execution.
void	registerTestExecutionListeners(TestExecutionListener... listeners)	Register one or more listeners for test execution.

Method Detail

registerTestExecutionListeners

void registerTestExecutionListeners(TestExecutionListener... listeners)

Register one or more listeners for test execution.

Parameters:

listeners - the listeners to be notified of test execution events; never null or empty

discover

TestPlan discover(LauncherDiscoveryRequest launcherDiscoveryRequest)

Discover tests and build a TestPlan according to the supplied LauncherDiscoveryRequest by querying all registered engines and collecting their results.

Parameters:

launcherDiscoveryRequest - the launcher discovery request; never null

Returns:

a TestPlan that contains all resolved identifiers from all registered engines

API Note:

This method should only be called to generate a preview of the test tree when executing tests is not desired. First calling this method to get access to the TestPlan and then execute(org.junit.platform.launcher.LauncherDiscoveryRequest, org.junit.platform.launcher.TestExecutionListener...) causes test discovery to be executed twice which may result in a significant performance degradation. Instead, execute(org.junit.platform.launcher.LauncherDiscoveryRequest, org.junit.platform.launcher.TestExecutionListener...) should be called directly and a TestExecutionListener that overrides TestExecutionListener.testPlanExecutionStarted(TestPlan) should be registered to get access to the test tree, for example to render it in an IDE.

execute

void execute(LauncherDiscoveryRequest launcherDiscoveryRequest,
             TestExecutionListener... listeners)

Execute a TestPlan which is built according to the supplied LauncherDiscoveryRequest by querying all registered engines and collecting their results, and notify registered listeners about the progress and results of the execution.

Supplied test execution listeners are registered in addition to already registered listeners but only for the supplied launcher discovery request.

Parameters:

launcherDiscoveryRequest - the launcher discovery request; never null

listeners - additional test execution listeners; never null

API Note:

In order to get access to the test tree, for example to render it in an IDE, register a TestExecutionListener that overrides TestExecutionListener.testPlanExecutionStarted(TestPlan) instead of calling discover(org.junit.platform.launcher.LauncherDiscoveryRequest) first.