Test scope left open if test injection fails

[nlativy]

We enter and exit test scope in TestEnvironment#beforeTest and TestEnvironment#afterTest respectively. The code in Acai which calls these methods looks like:

TestEnvironment testEnvironment = getOrCreateTestEnvironment(module);
testEnvironment.beforeSuiteIfNotAlreadyRun();
testEnvironment.beforeTest();
testEnvironment.inject(target);
try {
  statement.evaluate();
} finally {
  testEnvironment.afterTest();
}

If testEnvironment.inject(target) throws an exception we leave the scope open and all future tests fail with the exception:

java.lang.IllegalStateException: TestScope is already in progress.
    at com.google.common.base.Preconditions.checkState(Preconditions.java:177)
    at com.google.acai.TestScope.enter(TestScope.java:37)
    at com.google.acai.Acai$TestEnvironment.beforeTest(Acai.java:160)
    at com.google.acai.Acai$1.evaluate(Acai.java:78)

This also means, of course, that we fail to do any per-test tear-down as well in this case.

In fixing this issue another case to be aware of is that if a user defined @BeforeTest method fails currently this would also cause the TestScope to not be exited so simply moving testEnvironment.inject(target) into the try block will not make the code completely robust. We probably need to decouple the enter/exit scope from running @BeforeTest and @AfterTest methods.