Additional no match cases for EmptyCatch

[ben-manes]

Description of the problem / feature request:

EmptyCatch will skip matching when either (1) a comment or (2) a junit test is detected. It would be nice to extend this to a few more common patterns.

Feature requests: what underlying problem are you trying to solve with this feature?

1. If the exception is named ignored or expected. I believe this used to be part of the old Google Java style, which can be seen in Guava's JUnit tests. This would also match the behavior of PMD's EmptyCatchBlock rule.
2. Include detection of TestNG as skippable.

Bugs: what's the simplest, easiest way to reproduce this bug? Please provide a minimal example if possible.

// Static initializer fallback from Unsafe => MethodHandles => ThreadLocal
StripedBuffer.java:290: warning: [EmptyCatch] Caught exceptions should not be ignored
      } catch (Throwable ignored) {}

// TestNG unit test, e.g. assert NPE is thrown
CaffeineTest.java:133: warning: [EmptyCatch] Caught exceptions should not be ignored
    } catch (NullPointerException expected) {}

What version of Error Prone are you using?

2.4.0

[sumitbhagwani]

Looking at the style guide : https://google.github.io/styleguide/javaguide.html#s6.2-caught-exceptions

either the empty catch block should've comments with "exception" being test code where the exception name ok/expected/ignored etc are allowed.

EmptyCatch check (at HEAD/master as of July 2020) doesn't not flag JUnit test code.

So for feature requests :

1. such code should've comments - irrespective of exception param name
2. I think check should be extended for TestNG

[sumitbhagwani]

#1730 should fix this issue

[ben-manes]

Thanks!