Fix range formatting

[mroavi]

Fixes #1180, #1187, #1188, and probably #1184

Here is the idea:

1. We take as input the entire file and the range that should be formatted.
2. We enclose the given range by injecting two markers in the form of comments to the input file.
3. We format the result of step 2 (entire file with markers) using JuliaFormatter.jl. The output should include the injected markers.
4. We replace the given range in the input file with the code inside the markers of the output of step 3, and return this.

This approach avoids the need of having to deal with EXPRs and formats the given range in the context of the entire file.

[pfitzseb]

Generally LGTM and works very nicely. I've left a few comments inline.

[mroavi]

After the last changes, this case stopped working:

:lua vim.lsp.buf.format({ range = { ['start'] = {1,0}, ['end'] = {6,0} } })

Input:

function printx(x)

println("x = $x")
return

end

Output:

function printx(x)

  println("x = $x")
  return

endend

Since now we are only replacing the text inside the given range, it is more difficult to test because we cannot specify how the entire file has to look after formatting (see c05eaa7). This case is not caught by any of the tests because the returned formatted text is correct. However, it is misplaced in the input file. Any idea how we could make these tests more robust? I will look into why this case fails later this week.

[fredrikekre]

the returned formatted text is correct

Where does the extra end come from then?

[mroavi]

the returned formatted text is correct

Where does the extra end come from then?

The original one is not copied over, so we end up with two of them. We are probably making a wrong assumption about the presence of a newline char at the end of the given range. I noticed that if you add an empty line at the end of the file, then it works fine.

[fredrikekre]

What do you mean with copied over? Sounds like a mismatch in how you mark what is going to be formatted then? The end is included in the text to be formatted, but excluded from the range of replacement?

[mroavi]

What do you mean with copied over? Sounds like a mismatch in how you mark what is going to be formatted then? The end is included in the text to be formatted, but excluded from the range of replacement?

I mean that the end should be overwritten with the formatted end, which in this case looks exactly the same. I'm not sure where the issue comes from. It could be indeed an issue with how the range is marked. It could also be that the marking is being done properly but not the way in which we are replacing the text within the marks with the formatted text. I'll take a closer look today when I get home.

[fredrikekre]

I mean that since you insert regular line comments you must mark full lines to format, and then you must also replace the full line, not the original range, right?

[mroavi]

I mean that since you insert regular line comments you must mark full lines to format

Yes.

and then you must also replace the full line

we need to replace the introduced marks (comments) and all the lines inside the range.

We use this regex to do that:

https://github.com/mroavi/LanguageServer.jl/blob/1a12fc86426d8d37bcb554a8f2244ed32486793d/src/requests/features.jl#L214-L216

I see a \n in there which might be the issue. I think it should be optional in order to cover this case.

[mroavi]

And this is the other part that we modified:

https://github.com/mroavi/LanguageServer.jl/blob/1a12fc86426d8d37bcb554a8f2244ed32486793d/src/requests/features.jl#L220

which could also be the source of the problem. I don't have the laptop configured to debug LS.jl at the moment. I'll post an update as soon as I can test this a bit more.

[mroavi]

I'm sorry. This was all noise. The range formatting is working fine. I think I accidentally typed the undo button and disregarded the fix made here a765897. 😳

[fredrikekre]

Yea I couldn't reproduce. I played around a bit with the PR, is it OK if I push some changes to hopefully make it more resilient towards different lineendings?

[mroavi]

Please do so!

[HusterRichard]

When there is an empty line at the end of the code, the format selection operation will be performed. There will be the following error:
ERROR: BoundsError: attempt to access 3-element Vector{String} at index [1:4]
Stacktrace:
[1] throw_boundserror(A::Vector{String}, I::Tuple{UnitRange{Int64}})
@ Base .\abstractarray.jl:691
[2] checkbounds
@ .\abstractarray.jl:656 [inlined]
[3] view
@ .\subarray.jl:177 [inlined]
[4] textDocument_range_formatting_request(params::LanguageServer.DocumentRangeFormattingParams, server::LanguageServerInstance, conn::JSONRPC.JSONRPCEndpoint{Base.PipeEndpoint, Base.PipeEndpoint})
@ LanguageServer c:\Users\admin.vscode\extensions\julialang.language-julia-1.47.2\scripts\packages\LanguageServer\src\requests\features.jl:198
[5] (::LanguageServer.var"#111#112"{typeof(LanguageServer.textDocument_range_formatting_request), LanguageServerInstance})(conn::JSONRPC.JSONRPCEndpoint{Base.PipeEndpoint, Base.PipeEndpoint}, params::LanguageServer.DocumentRangeFormattingParams)
@ LanguageServer c:\Users\admin.vscode\extensions\julialang.language-julia-1.47.2\scripts\packages\LanguageServer\src\languageserverinstance.jl:267
[6] dispatch_msg(x::JSONRPC.JSONRPCEndpoint{Base.PipeEndpoint, Base.PipeEndpoint}, dispatcher::JSONRPC.MsgDispatcher, msg::Dict{String, Any})
@ JSONRPC c:\Users\admin.vscode\extensions\julialang.language-julia-1.47.2\scripts\packages\JSONRPC\src\typed.jl:67
[7] run(server::LanguageServerInstance)
@ LanguageServer c:\Users\admin.vscode\extensions\julialang.language-julia-1.47.2\scripts\packages\LanguageServer\src\languageserverinstance.jl:387
[8] top-level scope
@ c:\Users\admin.vscode\extensions\julialang.language-julia-1.47.2\scripts\languageserver\main.jl:104

[fredrikekre]

Fixed by #1228?