[2.1.0] Functional tests will fail if Global communicates with database

[omj]

[2.1.0] Functional tests will fail if Global communicates with database

[jroper]

As a workaround, could you try wrapping your onStart code in something that sets the context classloader to application.classloader?

[omj]

I have found the source of an exception. When I define

object SomeObject {
  lazy val db = Database.forDataSource(DB.getDataSource())
  // usage of 'db'
  // ...
}

and simply run application, everything is "fine" - database connection is retrieved from datasource and used until application shutdown. When I run functional tests: first test loads SomeObject, initializes session, does some work and exits. Second test loads SomeObject and reuses session which is expired (datasource is already closed).

Is it a bug or a feature of framework to reuse static objects?

This is why

If I replace this code with the method call of some instance of some class

helped.

Changing lazy val db = ... to def db = ... fixes the problem.
Is it fine to initialize slick's session this way on every request?

Also, I have additional tests that doesn't use Play's FakeApplication but communicate with database directly (via Database.forURL("jdbc:postgresql://localhost/test", ...)
I get SQLException: No suitable driver found for jdbc:postgresql://localhost/test (DriverManager.java:190) if at least one functional test was executed before. I can rewrite them to use "fakes" as a workaround but wondering why does it happen.

P.S. @jroper Please point out some tutorial/explanation about Play's context class loader (is your suggestion is still relevant regarding information above?).

[jroper]

The context classloader is a JVM thing, not a Play thing, it's the classloader attached to the current running thread, and I believe it's what JDBC uses to locate SQL drivers. Setting it looks something like this:

val old = Thread.current().getContextClassLoader()
try {
  Thread.current().setContextClassLoader(application.classloader())
  // Your code here
} finally {
  Thread.current().setContextClassLoader(old)
}

[jroper]

Caching a database session statically is not something that should ever be done. You should update it to def.