fix(declarative) withCredentails usernamePassword mocking conflict

[stchar]

Fixes #310

[nre-ableton]

Nice fix!

[Willem1987]

Question:

Why would we add a param in this case? The ParametersDeclaration has the string method when calling within a parameters closure.

When the string is called on the script outside the closure, i would not expect params to be added. That's why i did not go through the interceptor. Though i'm not sure if thats building on from #299

I see a clear difference between the string method being called as a param to a downstream build vs the string method inside the parametersdeclaration. I feel only the parametersdeclaration should actually add params.

[stchar]

@Willem1987 I cannot determine whether the string mock is called in which context (parameters {} or withCredentials([...]) {...} ) that's why I've implemented it as is

[Willem1987]

@stchar If i'm correct the call within the Parameters block should end up in ParametersDeclaration class first before getting to the outer lying script. But i could be mistaken. The tests seemed to work the way i tried to implement it

[stchar]

@Willem1987
It looks like parameters block should have it's own string interceptor or to be updated to support interceptor for withCredentials:

registerAllowedMethod('string', [Map]) acts differently in DeclarativePipelineTest and BasePipelineTest
But we hadn't seen any differences until withCredentials has been refactored in BasePipelineTest.

DeclarativePipelineTest inherits BasePipelineTest so withCredentials interceptor had been inherited
in DeclaratievePipelineTest which fired errors in my tests once I updated version of JPU up to 1.8

I would prefer ParametersDeclaration to shadow pipeline dsl but not to mock any pipeline plugins callbacks