Make it easy to test Generators derived from package:source_gen by
annotating test files.
@ShouldGenerate(
r'''
const TestClass1NameLength = 10;
const TestClass1NameLowerCase = testclass1;
''',
configurations: ['default', 'no-prefix-required'],
)
@ShouldThrow(
'Uh...',
configurations: ['vague'],
element: false,
)
@TestAnnotation()
class TestClass1 {}Other helpers are also provided.