Migrate all tests to Truth & use assertThrows

[Marcono1234]

Purpose

Migrate all tests to Truth & use assertThrows

Description

• Migrates all remaining tests to use Truth instead of JUnit for assertions
• Refactors all test code from try { ...; fail(); } catch (expected) { } to assertThrows
• Improves some tests

Checklist

• New code follows the Google Java Style Guide
  This is automatically checked by mvn verify, but can also be checked on its own using mvn spotless:check.
  Style violations can be fixed using mvn spotless:apply; this can be done in a separate commit to verify that it did not cause undesired changes.
• If necessary, new public API validates arguments, for example rejects null
• New public API has Javadoc
  • Javadoc uses @since $next-version$
    ($next-version$ is a special placeholder which is automatically replaced during release)
• If necessary, new unit tests have been added
  • Assertions in unit tests use Truth, see existing tests
  • No JUnit 3 features are used (such as extending class TestCase)
  • If this pull request fixes a bug, a new test was added for a situation which failed previously and is now fixed
• mvn clean verify javadoc:jar passes without errors

[eamonnmcmanus]

This is fantastic! Thanks for the many small improvements throughout, beyond just the mechanical transformation into assertThat and assertThrows.

Just a couple of very minor things.

[Marcono1234]

Sorry for the delay; I have added a few more test improvements. This pull request should now be ready.