VB -> C#: Missing conversion for array index assignment

[mrmonday]

Input code

Module Module1
    Sub Main()
        Dim x As New ArrayList
        x.Add("a")

        Dim xs(1) As String

        xs(0) = x(0)

    End Sub
End Module

Erroneous output

namespace ConsoleApp10
{
    static class Module1
    {
        public static void Main()
        {
            ArrayList x = new ArrayList();
            x.Add("a");

            string[] xs = new string[2];

            xs[0] = x[0];
        }
    }
}

Expected output

namespace ConsoleApp10
{
    static class Module1
    {
        public static void Main()
        {
            ArrayList x = new ArrayList();
            x.Add("a");

            string[] xs = new string[2];

            xs[0] = Conversions.ToString(x[0]);
        }
    }
}

Details

Version in use: master @ 2483369

[BrianFreemanAtlanta]

Attempting to look into this one. When I get into AnalyzeConversion the typeInfo/vbType = "ErrorType ?" Not sure if additional information is needed on the conversion or add a case for the ErrorType or take another tack.
If you'd like me to do a pull request with the test case in it I can do that.

[GrahamTheCoder]

If you see ErrorType or ErrorSymbol it generally means the compilation had errors.
If you look at _semanticModel.GetDiagnostics() you'll be able to see them.
In this case, adding an import should cover it:

Imports System.Collections

Public Module Module1
	Sub Main()
        Dim x As New ArrayList
        x.Add("a")

        Dim xs(1) As String

        xs(0) = x(0)

    End Sub
End Module

Other stuff:

• There's also a _showCompilationErrors flag I use for showing errors in the test output, but I recently broke it. It'll be fixed again as part of Enable checks that test conversion code compiles #60
• Ideally that System.Collections import would have been automatically added for all conversions since it's a common one (and unused imports get removed at the end). Things like that should go into the list here: https://github.com/icsharpcode/CodeConverter/blob/master/ICSharpCode.CodeConverter/Util/VisualBasicCompiler.cs#L58 which if it "just works" would probably be a better fix rather than changing the test. There's a list of all .NET framework namespaces here: I'd be tempted to add literally all of them...though that would cause potential ambiguities with existing using statements (or each other), so it'd probably be better to either investigate which contain clashing type names (with a bit of reflection investigation), or just pick ones from that list that we've actually ever seen used. I wish I could crawl github for the most commonly used using statements...maybe just add the one for now and we'll do more on this another time.

[GrahamTheCoder]

Generally it's also worth just having a solution with a VB and a CS project open alongside the code converter for checking syntax.