Unencumbered V0.1.2: Write Cucumber step definitions in D

[Rikki Cattermole via Digitalmars-d-announce]

On Friday, 25 April 2014 at 08:52:18 UTC, Atila Neves wrote:
> On Friday, 25 April 2014 at 08:45:20 UTC, Atila Neves wrote:
>> On Thursday, 24 April 2014 at 18:53:22 UTC, Jacob Carlborg 
>> wrote:
>>> On 2014-04-23 15:24, Atila Neves wrote:
>>>> Like testing with Cucumber? Wish you could call native D 
>>>> code with it?
>>>> Now you can!
>>>>
>>>> http://code.dlang.org/packages/unencumbered
>>>> https://github.com/atilaneves/unencumbered
>>>>
>>>> I especially like registering functions that take the 
>>>> parameters with
>>>> the types they need from the regexp captures, as well as the
>>>> compile-time failures that come from that if done 
>>>> incorrectly.
>>>>
>>>> Now I just need to use in "real life".
>>>
>>> BTW, why is the description passed as a template argument to 
>>> the Cucumber keywords. @Given!("foo") instead of 
>>> @Given("foo")?
>>
>> Ehm... because until now I didn't know that @Given("foo") was 
>> possible. In my head I was doing compile-time stuff so 
>> everything had to be compile-time, if that makes any sense.
>>
>> After I read the above I wasn't even sure how @Given("foo") 
>> would work so I wrote some code and now know that all I need 
>> is a struct with a regular string field. I think the 
>> documenation on http://dlang.org/attribute.html is severely 
>> lacking.
>>
>> I think I have some refactoring to do now. Thanks for pointing 
>> this out!
>>
>>
>> Atila
>
> Hmm. So for the string argument is fine, unfortunately I also 
> need to know the line number of the step definition, and that 
> doesn't work:
>
> struct Given {
>     this(string s, ulong l = __LINE__) {
>         this.s = s;
>         this.l = l;
>     }
>     string s;
>     ulong l;
> }
>
>
> @Given("foobar")
> auto func() pure nothrow @safe {
>
> }
>
> void main() {
>     foreach(attr; __traits(getAttributes, func)) {
>         pragma(msg, "s is ", __traits(getMember, attr, "l"));
>     }
> }
>
>
> I get:
>
> s is attr_str.d(21): Error: variable attr cannot be read at 
> compile time
> attr_str.d(21):        while evaluating pragma(msg, 
> __traits(getMember, attr, "l"))

struct Given {
     this(ulong l = __LINE__)(string s) {
         this.s = s;
		this.l = l;
     }
     string s;
     ulong l;
}


@Given("foobar")
auto func() pure nothrow @safe {

}

void main() {
	pragma(msg, "s is ", getGivenL!func);
}

pure ulong getGivenL(alias symbol)() {
	foreach(attr; __traits(getAttributes, func)) {
		static if (is(typeof(attr) == Given)) {
			return attr.l;	
		}
	}
	assert(0);
}

Basically move the "checking" of UDA's to specialist functions 
that are reusable.
Also when using things like __LINE__ keep them to template args, 
as they are inferred to the initiation if possible.