Parsing csharp files does not recognize the language

[dpordomingo]

discovered at https://github.com/src-d/empathy-sessions/issues/37#issuecomment-470045137

Running parse over a .cs file is not working

$ srcd parse uast examples/example.cs
INFO[0000] detected language: c#                        
Error: language c# is not supported
Usage:
  srcd parse uast [file-path] [flags]
...

Workaround

Until this is fixed, csharp needs to be passed explicitly to bblfshd. For example:

srcd parse uast csharp.cs --lang csharp

[smacker]

This is a known problem in bblfsh:

• Closed Issue
• Workaround that closed the issue
• It does not include fix for supported languages
• Issue for proper fix

We use supported languages API to provide meaningful error to the user.

So the question is: do we want to implement workaround inside engine specially for C#?

//cc @creachadair maybe you have some ETA for the proper fix on bblfsh side?

[creachadair]

My understanding was that the fix from bblfsh/bblfshd#251 was supposed to address this without requiring a change to Engine. To really fix this we will need a solution for aliasing, for which we don't have a timeline yet (@bzz has started an RFC for the question, but we have had higher-priority work so far).

Is the above workaround not working for you?

[smacker]

it does not. We use enry + bblfsh supported languages api to check that bblfsh is able to parse a file. This api currently doesn't return c#, only csharp.

[creachadair]

it does not. We use enry + bblfsh supported languages api to check that bblfsh is able to parse a file. This api currently doesn't return c#, only csharp.

I see. So is the issue not that you're unable to get a parse for the file, but that the list of languages doesn't match the string on the Engine side so that Engine doesn't even ask?

[smacker]

@creachadair yes

jfyi workaround from above also doesn't solve the issue for srcd sql and for gemini (which isn't part of engine yet).

[carlosms]

I added this as a known issue to the release notes.

[smacker]

I would propose to return this issue to backlog and wait for the fix from LA team instead of implementing work around on our side due to:

• we can work around only parse command, not gitbase
• there is a chance we will remove parse command completely from engine

@carlosms wdyt?

[carlosms]

Makes sense, let's wait for a proper fix, I don't think there is any rush.

[carlosms]

It also fails for cpp (c++ is not supported) and bash (shell is not supported).

[campoy]

It seems like C# is then not supported in any way other than language detection for the Engine.
I'd consider simply dropping mentions to C# on the release notes for 0.11.