Added ability to add parameter description attributes

[jsheely]

There was no way to add descriptions to query param without using XML comments.

[heldersepu]

Some unit tests will be nice...

[jsheely]

Ref work done in AspNetCore version domaindrivendev/Swashbuckle.AspNetCore#554

[heldersepu]

@jsheely
I Like the unit test, nicely done!
But why SwaggerDescriptionAttribute? I liked it better the way you had it before...

[jsheely]

After thinking about it using System.ComponentModel.DescriptionAttribute felt like overloading that attribute. This way it fits better with all the other swagger specific attributes. I wouldn't want there to be a situation where someone wanted to use [Description] for a model property in the UI but have a different description in the API.

Perhaps there could be an option to enable using [Description] for anyone who wants that.

[jsheely]

Here is a good reason to use [SwaggerDescription] instead of [Description]. Now I can add summary to the heading of each method.

[heldersepu]

See the build log:

Swagger\SchemaExtensions.cs(57,41): error CS1525: Invalid expression term '.' [C:\projects\swashbuckle\Swashbuckle.Core\Swashbuckle.Core.csproj]
Swagger\SchemaExtensions.cs(57,42): error CS1003: Syntax error, ':' expected [C:\projects\swashbuckle\Swashbuckle.Core\Swashbuckle.Core.csproj]
Done Building Project "C:\projects\swashbuckle\Swashbuckle.Core\Swashbuckle.Core.csproj" (default targets) -- FAILED.
The target "_ConvertPdbFiles" listed in a BeforeTargets attribute at "C:\Program Files

[heldersepu]

I think the compiler does not like your short syntax:
schema.description = attrib?.Description;

[jsheely]

Any idea how to update the AppVeyor compiler to do the right thing? I'd rather not have to change the operator. I really like the null check operator.

[heldersepu]

What version of Visual Studio are you using?
This project shows 2013 on the solution:
https://github.com/domaindrivendev/Swashbuckle/blob/master/Swashbuckle.sln

I don't think that was available back then...

[jsheely]

Well I made the build work. But I have no idea why appVeyor doesn't build the same way as it does locally. Should be using Visual Studio 2017.

[Liero]

But I have no idea why appVeyor doesn't build the same way as it does locally. Should be using Visual Studio 2017.

I recommend to explicitly set C# language version in project properties -> build -> advanced. The default settings uses latest available C# version. which depends on version of Visual Studio you (or the build server) are using.