Launcher (junit-platform-launcher 1.0.1 API)

```
@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.
Discovery and execution of tests require a LauncherDiscoveryRequest which is passed to all registered engines. Each engine decides which tests it can discover and later execute according to the LauncherDiscoveryRequest.
Clients of this interface may optionally call discover(org.junit.platform.launcher.LauncherDiscoveryRequest) prior to execute(org.junit.platform.launcher.LauncherDiscoveryRequest, org.junit.platform.launcher.TestExecutionListener...) in order to inspect the TestPlan before executing it.
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. For example, 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

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and 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
  - 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

Interface Launcher

Method Summary

Method Detail

registerTestExecutionListeners

discover

execute