TechTalk.SpecFlow.BindingException: 'Parameter count mismatch! The binding method

user_10127198 0
Viewed 5668

I am trying to write a StepArgumentTransformation for specflow.

I have following gherkin

Scenario: Test Arguments
Given user enter once as 2

And I have written this in step definition.

    [StepArgumentTransformation]
    public int GetOnces(string onces, string times)
    {
        return 1 * int.Parse(times);
    }

    [Given(@"user enter (.*) as (.*)")]
    public void GivenUserEnterOnce(int num)
    {
        Assert.Equal(2, num);
    }

But GetOnces method is never called and I get the exception

TechTalk.SpecFlow.BindingException: 'Parameter count mismatch! The binding method 'GivenUserEnterOnce(Int32)' should have 2 parameters

specflow gherkin c#
2 Answers

The bindings should be like this:

[StepArgumentTransformation("(.*) as (.*)")]
public int GetOnces(string onces, string times)
{
    return 1 * int.Parse(times);
}

[Given(@"user enter (.*)")]
public void GivenUserEnterOnce(int num)
{
    Assert.Equal(2, num);
}

If it's more than one parameter you want to transform, you have to specify the regex at the StepArgumentTransformation. Your real step only get's one parameter, so only one parameter in the regex is valid.

You find the documentation for this here: https://specflow.org/documentation/Step-Argument-Conversions/

user_31553230

For me the problem was just that I forgot/removed the "Then" line in my scenario

user_62555780
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