Parallel test case execution

[haresh-codi]

Hey how to run test cases parallely in scala using play framework
Also I have added both these in build.sbt but still not running test cases in parallel

fork in Test := true
parallelExecution in Test := true

[mkurz]

AFAIK parallelExecution in Test := true alone does not help for all scenarios. Take a look here:

playframework/testkit/play-test/src/main/scala/play/api/test/Helpers.scala

Lines 50 to 67 in 6ddc99c

	/**
	* Tests using servers share a test server port so we default to true.
	*/
	protected def shouldRunSequentially(app: Application): Boolean = true
	private[play] def runSynchronized[T](app: Application)(block: => T): T = {
	val needsLock = shouldRunSequentially(app)
	if (needsLock) {
	PlayRunners.mutex.lock()
	}
	try {
	block
	} finally {
	if (needsLock) {
	PlayRunners.mutex.unlock()
	}
	}
	}

When "running" a Play app or server in tests, these by default still get executed sequentially, because of runSynchronized. You can override shouldRunSequentially to change that, like we do here:

playframework/core/play-integration-test/src/test/scala/play/it/http/websocket/WebSocketSpec.scala

Line 446 in 6ddc99c

protected override def shouldRunSequentially(app: Application): Boolean = false

and here:

playframework/core/play-integration-test/src/test/scala/play/it/http/JavaResultsHandlingSpec.scala

Line 44 in 6ddc99c

protected override def shouldRunSequentially(app: Application): Boolean = false

This behaviour was added because of what's written in the comment:

* Tests using servers share a test server port so we default to true.

However with Play 2.9 / 3.0 tests that open a port will run on a random port now, so we should be able to set shouldRunSequentially to false by default or even completely remove the runSynchronized method.
Not just because of that, but also now that since a couple of Play versions we do not have a global app enabled by default anymore:

playframework/testkit/play-test/src/main/scala/play/api/test/TestServerFactory.scala

Lines 56 to 62 in 6ddc99c

	/**
	* Get the lock (if any) that should be used to prevent concurrent
	* applications from running.
	*/
	protected def optionalGlobalLock(app: Application): Option[Lock] = {
	if (app.globalApplicationEnabled) Some(PlayRunners.mutex) else None
	}

So this runSynchronized method comes from a time when we still used a fixed port for tests and a global app...

However AFAIK, when I worked on the random port thing a couple of months ago, and if I recall correctly, there is more stuff that needs to be done so we can switch to false by default (because I tried that back then 😉), like

• Correctly shutdown current active LoggerConfigurator on app (re)load in DEV mode #10939, which otherwise makes a lot of tests failing.

This is something to be looked into Play 2.10 and 3.1.

BTW, if you use Play Java the same is true like described above, see:

playframework/testkit/play-test/src/main/java/play/test/Helpers.java

Lines 561 to 563 in 6ddc99c

	public static void running(
	TestServer server, WebDriver webDriver, final Consumer<TestBrowser> block) {
	Helpers$.MODULE$.runSynchronized(

[mkurz]

Added an issue:

• Set shouldRunSequentially to false by default or just remove runSynchronized #12214

[janani-reddy9]

Hi @mkurz, I was looking into the issues and PR's mentioned wrt this.
If I understood correctly, To have parallel running of test cases, PR - #10939 need to be worked on first.

I have a quick doubt wrt this. I saw the implementations of DevServerStart and ProdServerStart. I couldn't understand the need to initialise LoggerConfigurator before the start of application in DevServerStart?