C# -> VB code comments are not converted

[paul1956]

It looks like they are just ignored.

[christophwille]

Oops, I didn't copy over https://github.com/icsharpcode/RefactoringEssentials/blob/5857519150dc5084286e05f556a260558d700941/converter.txt - it has the latest recent list of limitations in the converter. And yes, comments are being ignored (main reason was that other statements are way more important to convert than comments)

[paul1956]

Any hints on where to start on implementing comments in C# to VB? I tried simply adding a .WithTriviaFrom and passing the original C# Node and that does nothing useful. Also getting a better match on line breaks, right now most multiline C# statements get converted to a single line. I have implemented coloring of source and output in a desktop converter and it was fairly trivial and have converted entire source to VB (passing all tests) if anyone is interested. One small suggestion, you might want to use LanguageNames throughout instead of "Visual Basic" and "C#" it makes the code less susceptible to typos.

[siegfriedpammer]

When initially implementing the converter I could not come up with a way to deal with all the edge cases that arise from allowing preprocessor directives and comments.

For example:

#if SOMETHING
if (
#else
switch (
#endif
)

I guess we'd have to change the converter to convert each token individually. Not sure how to go about that.

[paul1956]

I don't see why your example is a problem, I just translate the trivia syntax but I have not done #If yet because I am having trouble getting into the DirectiveTrivia.

I added the 2 lines below to the top of every NodeVisitor function

Dim LeadingTriviaList As SyntaxTriviaList = CreateVBTriviaListFromCSharpNode(node.GetLeadingTrivia())
Dim TrailingTriviaList As SyntaxTriviaList = CreateVBTriviaListFromCSharpNode(node.GetTrailingTrivia())

and to the end of every return statement I add

.WithLeadingTrivia(LeadingTriviaList).WithTrailingTrivia(TrailingTriviaList)

I also had to do a little fixing to TidyImports and now most stuff just works. So far I have only partially implemented CreateVBTriviaListFromCSharpNode to handle regions and single line comments. The whole thing took about 4 hours over several days. I still need to see why I am missing a blank line between comments and the next statement and why some tests fail because of an extra blank line at the beginning that I am adding. Without the comments and region addition my VB version of your code passes 100% of the tests. I also have a desktop code converter with syntax highlighting that today converts files but I am adding folders and projects shortly. Eventually I would like to add As Clauses instead of Option Infer (which should be added to the top of every current conversion that uses var) but I am having lots of issues trying to get that to work even in a Visual Studio VSIX.

[paul1956]

The issue with the extra blank line is not mine, it is in your tests. You have an extra blank before class and I now preserve all the formatting.

	TestConversionCSharpToVisualBasic(@"
class TestClass 

But in the result you don't have the leading blank line

}", @"Class TestClass

[siegfriedpammer]

You are welcome to submit a pull request with your changes. Please note that I have stepped down from my role as maintainer of the code converter long ago.

The project is looking for a new maintainer. However, if you submit a pull request I will take a look and merge it.

The issue with the extra blank line is not mine, it is in your tests.

I don't think you could call this an "issue". Since you are adding new information to the output that has not been there previously, it's obvious that the tests will have to be adjusted.

[paul1956]

I don't understand enough about GitHub to do a pull request. Agree an issue was a poor choice of words.

[siegfriedpammer]

Take a look at https://yangsu.github.io/pull-request-tutorial/ for a simple step-by-step guide to pull requests. Thank you in advance for your work!

[siegfriedpammer]

I've noticed that you had some VB.NET code in your comment above... why is your snippet showing VB.NET when our codebase is C#?

[paul1956]

Because I code in VB, I have ported your entire codebase to VB (using a combination of this converter and others). If I decide to contribute (and can get it to work using instructions above) I with back port to C# before posting. I have Comment's and Regions working now. and am just working on additional tests. I am having issues preserving original formatting (notice the missing line feed at the top, the conversion is correct until the call to .NormalizeWhitespace at the end).

I would like to start with something very simple like using LanguageName instead of literals throughout the code. If that works I will tackle comments and regions followed by convert folder if there is interest.

[GrahamTheCoder]

I've got a WIP branch for porting code comments VB -> C#, but it needs a bit of tidying up and some dedicated tests adding: GrahamTheCoder#4

I've tried to do it in a way that stays separate from the rest of the code, though there are edge cases around constructs that change shape which make this tricky, and might need a few overrides for certain types (hence using the visitor).
C# -> VB can probably be implemented as approximately the opposite conversion, happy to discuss further. Apologies for not noticing this thread sooner (I'd forgotten to watch the new repo) - I've now opened issues linking to my ongoing work so it's more visible in future.