GetFullName in TypeExtensions.cs not handling arrays correctly

[kcamp]

What You Are Seeing?

When creating a CakeMethodAlias method with a params System.Linq.Expressions.Expression<Func<string,string>> expressions parameter, the resulting Roslyn compilation fails.

Error: Roslyn.Compilers.CompilationErrorException: (1918,131): error CS0231: A params parameter must be the last parameter in a formal parameter list
   at Roslyn.Scripting.CommonScriptEngine.CompilationError(DiagnosticBag localDiagnostics, DiagnosticBag diagnostics)
   at Roslyn.Scripting.CommonScriptEngine.Compile(String code, String path, DiagnosticBag diagnostics, Session session, Type delegateType, Type returnType, CancellationToken cancellationToken, Boolean
 isInteractive, Boolean isExecute, CommonCompilation& compilation, Delegate& factory)
   at Roslyn.Scripting.CommonScriptEngine.Execute[T](String code, String path, DiagnosticBag diagnostics, Session session, Boolean isInteractive)
   at Roslyn.Scripting.Session.Execute(String code)
   at Cake.Scripting.Roslyn.Stable.DefaultRoslynScriptSession.Execute(Script script) in C:\git\cake\src\Cake\Scripting\Roslyn\Stable\DefaultRoslynScriptSession.cs:line 31
   at Cake.Core.Scripting.ScriptRunner.Run(IScriptHost host, FilePath scriptPath, IDictionary`2 arguments) in C:\git\cake\src\Cake.Core\Scripting\ScriptRunner.cs:line 189
   at Cake.Commands.BuildCommand.Execute(CakeOptions options) in C:\git\cake\src\Cake\Commands\BuildCommand.cs:line 33
   at Cake.CakeApplication.Run(CakeOptions options) in C:\git\cake\src\Cake\CakeApplication.cs:line 46
   at Cake.Program.Main() in C:\git\cake\src\Cake\Program.cs:line 69

What is Expected?

I would expect the compilation to work as expected.

What version of Cake are you using?

0.14

Are you running on a 32 or 64 bit system?

x64

What environment are you running on? Windows? Linux? Mac?

Windows

Are you running on a CI Server? If so, which one?

No

How Did You Get This To Happen? (Steps to Reproduce)

Author a Cake add-in with the following method signature - actual implementation is obfuscated, it's the method signature that's causing the issue.

[CakeMethodAlias]
public static object DoSomething(this ICakeContext context, FilePath path, params Expression<Func<string, string>>[] properties)
{
    if (context == null)
    {
        throw new ArgumentNullException(nameof(context));
    }

    // implementation ...

    throw new NotImplementedException();
}

Output Log

https://gist.github.com/kcamp/b08e1b5527baf2216a8005628652dbef

Further investigation shows that the underlying code being serialized for Roslyn in RoslynCodeGenerator.cs is malformed.

public object DoSomething(Cake.Core.IO.FilePath path, params System.Linq.Expressions.Expression`1[[System.Func`2[[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]][] properties)
{
    return My.NameSpace.ProjectAliases.DoSomething(Context, path, properties);
}

[kcamp]

I have a fix for this and will submit a PR shortly

[devlead]

@kcamp thanks notifying us about this issue 👍 , for your PR please start Cake with -mono flag to so we see if mono has the same issue and it gets resolved there too.