如何生成列表<T>在 SpecFlow 场景的步骤定义中？

Question

In the documentation for SpecFlow Step Definitions it shows an example where you can create a list in the step definition by using a comma separated list in the scenario:

For example:

Given I am available on "Tuesday,Friday,Sunday"

would result in:

@Given("I am available on \"(.+)\"")
public void I_have_cukes_in_my_belly(List<String> days) {
    // Do something with the days
}

Unfortunately, when I do it, I get this:

@Given("I am available on ""(.*)"")
public void I_have_cukes_in_my_belly(string days) {
    // Do something with the days
}

I am using VS 2012 and version 1.9.1 of SpecFlow. Does anyone have any idea what I might be doing wrong? Or how I can go about fixing this?

Thanks in advance.

Answer 1

You could do something like:

Given I am available on these days:

| DaysOfWeek |

| Monday |

| Tuesday |

| Wednesday |

Then you could use the table and convert that to a list...

@Given("I am available on these days:")
public void I_have_cukes_in_my_belly(Table table) {
    List<string> days = new List<string>();
    foreach (var tableRow in table.Rows)
    {
        days.Add(tableRow["DaysOfWeek"]);
    }
 }

Answer 2

The only language that seems to support Lists currently is Java. I'm assuming you're using C# as you're using VS2012. If you switch the code sample on your linked page to C# instead of Java, the List example goes away and I'm seeing the same behavior you are.

However, you can simply get the string as a parameter and put it into a List. 1 line.

C#

[Given(@"I am available on ""(.*)""")]
public void GivenIAmAvailableOn(string days)
{
        List<String> daysList = new List<string>(days.Split(','));

Answer 3

您可以尝试查询 Table 实例以获取您要查找的列表。

expectedTable.Rows.Select(row => row.Values.FirstOrDefault()).ToList()

Answer 4

If you click C# on the Step Definitions page you will see that the List examples disappear. However as OCary points out you can simulate it by splitting the string.

But I would suggest that there is no need to cast back to list and you can just use IEnumerable via Linq instead so you can parse the list more simply ie

[Given(@"I am available on ""(.*)""")]
public void GivenIAmAvailableOn(string days)
{
    var daysList = from x in days.Split(',') select x.Trim();

Answer 5

Currently I'm using a step argument transformation to get the list right:

[StepArgumentTransformation(@"((?:.*)(?:,.*)*)")]
public List<string> StringToList(string list)
{
    // (
    //    (?:    - Don't capture
             .*  - Match any character
    //    )
    //    (?:    - Don't capture
    //       ,   - Separated by a comma
    //       .*  - Match any character
    //    )*     - Zero or more items after the first item
    // )

    return list
        .Split(',')
        .Select(x => x.Trim())
        .ToList();
}

Then you'd be able to use List<string> as the argument type, like so:

[Given(@"I am available on ""(.*)""")]
public void GivenIAmAvailableOn(List<string> days)
{
}

Answer 6

Use Table to IEnumerable<T> convertor:

[StepArgumentTransformation]
public static IEnumerable<string> ToStringEnumerable(Table table) =>
    table.Rows.Select(t => t.Values.Single());

Then you can use it as in your example (or cast to List<T> if you like):

@Given("I am available on \"(.+)\"")
public void I_have_cukes_in_my_belly(IEnumerable<String> days) {
    // Do something with the days
}