T> class Null safety
An abstract base class for describing test environment variants.
These serve as elements of the
variants argument to testWidgets.
Use care when adding more testing variants: it multiplies the number of tests which run. This can drastically increase the time it takes to run all the tests.
A const constructor so that subclasses can be const.
T value ) → String
- Returns the string that will be used to both add to the test description, and be printed when a test fails for this variation.
Invocation invocation ) → dynamic
Invoked when a non-existent method or property is accessed. [...]
T value ) → Future< Object>
- A function that will be called before each value is tested, with the value that will be tested. [...]
T value, covariant Object memento ) → Future< void>
- A function that is guaranteed to be called after a value is tested, even if it throws an exception. [...]
) → String
Returns a string representation of this object.