list of numbers as parameter in specflow test step

Question

I am looking for a way to have a step definition such as:

Given a collection of numbers 1,2,3,4

and map that to a step definition with either a int[], List, or IEnumerable

the regex (\d+(,\d+)*) matches, but means I need two parameters.

At present I have

[Given(@"a collection of numbers (\d+(,\d+)*)")]
public void givencollectionofnumbers(string p0, string p1)
{
    //p0 is "1,2,3,4"
    //p1 is ",4"
}

I have a simple workarouns that is

[Given(@"a collection of numbers (.*)")]
public void givencollectionofnumbers(string p0)
{
    var numbers = p0.Split(',').Select(x => int.Parse(x));
}

but I would like to do this in a more elegant manner potentially changing the type of the numbers to doubles and also ensuring that the regex only maches lists of numbers.

I also would rather not use a table for this as it seems excessive for simple list of data

Can anyone help with this

Answer 1

I just resolve the same issue on my project: this will do the trick

((?:.,\d+)*(?:.\d+))

If you want to accept single int as well, use this instead:

((?:.,\d+)*(?:.+))

There are 2 problems with your proposition :

• Specflow try to match it as 2 parameters, when you need only 1. But I was unable to find a clear explanation of why it did that in the documentation

• you definitely need a StepArgumentTransformation to transform your input string in any enumerable

So your final step functions will look like that:

[Given(@"foo ((?:.,\d+)*(?:.+))")]
public void Foo(IEnumerable<int> ints)
{
}

[StepArgumentTransformation(@"((?:.,\d+)*(?:.+))")]
public static IEnumerable<int> ListIntTransform(string ints)
{
    return ints.Split(new[] { ',' }).Select(int.Parse);
}

And you receive an Enumerable int in your Foo function.

Hope it helps.