Add "But" step support

[jason-roberts]

Idea for future enhancement.

Add support for "But" just as there is already support for "And",

e.g.
Given A
When B
Then C
And D
But not XYZ

[MehdiK]

The syntax is very ungherkinish; but you can already do this in both Fluent and Reflective APIs. But is basically a variation of AndThen. In Fluent API just go:

this.Given(_ => GivenA())
      .When(_ => WhenB())
      .Then(_ => ThenC())
      .And(_ => AndD())
      .And(_ => ButNotXyz())

You can create your own method name conventions (or customize the existing one) and add But in. See this for details, and from there you can write:

void GivenA() {}
void WhenB() {}
void ThenC() {}
void AndD() {}
void ButNotXyz() {}

And if you like ExecutableAttributes and/or don't want to add But as a naming convention you could create your own custom ButAttribute and use it as:

void GivenA() {}
void WhenB() {}
void ThenC() {}
void AndD() {}
[But]
void ButNotXyz() {}

[JakeGinnivan]

I also like using the Should syntax

Given A
When B
Then C
And D should be foo
And XYZ should not be bar

Which gets around the issue

[mwhelan]

With the reflective API, you can create a new MethodNameStepScanner and add this line into the constructor stepTextTransformer func:

new MethodNameMatcher(s => s.StartsWith("But", StringComparison.OrdinalIgnoreCase), true, ExecutionOrder.ConsecutiveAssertion, true),

and then add your custom scanner during appdomain initialize:

Configurator.Scanners.DefaultMethodNameStepScanner.Disable();
Configurator.Scanners.Add(() => new CustomMethodNameStepScanner());

There is a complete example in the documentation:
http://docs.teststack.net/BDDfy/Customizing/ExampleCustomFramework.html

[jason-roberts]

Yeah, I was just thinking if it would be a good thing to have out of the box for people that might be coming from a tool such as SpecFlow, to possibly ease the migration path??

[MehdiK]

Oh, look at this!! Gherkin DOES support And and But steps! So I think we should do it.

Thanks for reporting this.

[mwhelan]

Maybe we should if Gherkin supports it, though I struggle to see the difference between "but" and "then."

[JakeGinnivan]

Yeah, anything to ease migration from specflow is a great idea. I did not realise it was part of gherkin. Lets do it

[MehdiK]

@mwhelan I agree. There is no difference really. Just syntactic sugar, and one that I personally consider quite unnecessary. At the same time though if it's in Gherkin I think we should do it, and also it's quite easy to add.

[mwhelan]

Agreed

On Tue, Apr 8, 2014 at 7:37 PM, Mehdi Khalili notifications@github.comwrote:

@mwhelan https://github.com/mwhelan I agree. There is no difference
really. Just syntactic sugar, and one that I personally consider quite
unnecessary. At the same time though if it's in Gherkin I think we should
do it, and also it's quite easy to add.

Reply to this email directly or view it on GitHubhttps://github.com//issues/85#issuecomment-39885200
.

[mwhelan]

So, should there be "And But" like there is "And Then?"

[MehdiK]

Nope. Just But to comply with Gherkin.