unencumbered 0.2.0

Unencumbered

Unencumbered allows Cucumber to support step definitions written in D.

This is done by implementing the Cucumber wire protocol. The best way to get a feel for how it's used is to look at the calculator example. To run it,type dub run in the examples directory and cucumber from the same directory in another shell.

Unencumbered works by using compile-time reflection to find all the Cucumber step definitions written in D. That means that the server to be run for testing needs to make a call to runCucumberServer with all the modules to include in the search as compile-time string parameters.

Notice that the calculator example steps register functions that vary in the number of arguments they can take, as well as the type of those arguments. Some have to parameters, some take double parameters and one takes just one string argument. The compile-time reflection generates code to convert any regular expression capturing parentheses matches to the type(s) in the function declaration.

If the type is not convertible at run-time, an exception will be thrown. If a function with arity different from the number of capturing parentheses is registered, the code will not compile (try it and see!). If the regular expression is invalid (e.g. because a capturing parenthesis is never closed), a compile-time (CTFE) exception is thrown, so the code won't compile in that case either.

Step definitions are supposed to test the code and signal failure by throwing any Throwable. The examples use the check functions from unit-threaded, but regular assert or anything else that throws on failure would work too. Unencumbered actually reports the exception type and message back to Cucumber over the wire protocol.