Tracking lsp spec compliance (from version 3.3)

[lukel97]

EDITED by @jneira: we are gonna put here the main checklist of features to give it more visibility

3.3

• CompletionContext
• MarkupContent (done for Hover, still needed for some others) tracked by Support MarkdownClientCapabilities #329

3.11

• Add support for CodeActionOptions to allow a server to provide a list of code action it supports.

3.12

• Add support for textDocument/prepareRename request.

3.13

• File and folder operations (create, rename, move) to workspace edits.

3.14

• Signature label offsets.
• Location links.
• textDocument/declaration request.

3.15

• generic progress reporting.
• specific work done progress reporting support to requests where applicable.
• specific partial result progress support to requests where applicable.
• textDocument/selectionRange.
• server and client information.
• signature help context.
• add version on PublishDiagnosticsParams
• CodeAction#isPreferred.
• CompletionItem#tag.
• Diagnostic#tag.
• Add DocumentLink#tooltip support.
• Add trimTrailingWhitespace, insertFinalNewline and trimFinalNewlines to FormattingOptions.
• Add support for context in SignatureHelpRequest (noted by @bubba in Add support for context in SignatureHelpRequest #190)

3.16

• Call Hierarchy support, needed for Support for function call hierarchy haskell-language-server#738
• Semantic Token support. Tracked with Add support for semantic highlighting (LSP 3.16) #240, needed for Semantic tokens in HLS haskell-language-server#1654
• insert and replace ranges on CompletionItem
• diagnostic code descriptions
• tags on SymbolInformation and DocumentSymbol
• Monikers
• Linked editing
• Change annotation support for text edits and file operations
• Locale
• Diagnostic data
• MessageActionItem additional properties
• create/rename/delete notifications
• normalizesLineEndings
• Support for client default behavior on renames.

[EggBaconAndSpam]

I would love support for this one in particular:

3.13

* [ ]   Add support for file and folder operations (create, rename, move) to workspace edits.

[lukel97]

@EggBaconAndSpam I believe we are yet to add workspace support first. I think we have the types defined, but yes this would be a great feature to have! It might be nice to have a separate issue for this since there’s probably a lot of discussion needed around how the VFS/api will work around it, assuming that we’re adding deeper integration than just handlers.

[EggBaconAndSpam]

My use-case is the following: I would like to be able to create files via the "workspace/applyEdit" command; as far as I understand it workspaces as a concept are largely orthogonal to this feature. Currently the corresponding haskell-lsp-types definition only covers edits to existing files:

(From WorkspaceEdit.hs)

data WorkspaceEdit =
  WorkspaceEdit
    { _changes         :: Maybe WorkspaceEditMap
    , _documentChanges :: Maybe (List TextDocumentEdit)
    } deriving (Show, Read, Eq)

Which corresponds to documentChanges?: TextDocumentEdit[];, while the new spec extends this to documentChanges?: (TextDocumentEdit[] | (TextDocumentEdit | CreateFile | RenameFile | DeleteFile)[]);. I propose something along these lines:

data DocumentChange = DCEdit TextDocumentEdit
                    | DCCreate CreateFile
                    | DCRename RenameFile
                    | DCDelete DeleteFile


data WorkspaceEdit =
  WorkspaceEdit
    { _changes         :: Maybe WorkspaceEditMap
    , _documentChanges :: Maybe (List DocumentChange)
    } deriving (Show, Read, Eq)

[thomasjm]

I just made a pair of PRs for 3.11 and 3.12 support. They're not really adequately tested yet but hopefully this is a step in the right direction.

[michaelpj]

Support for changeAnnotations and AnnotatedTextEdit would be nice.

[michaelpj]

#290 should fix the last remaining place that needs MarkupContent, and one other minor 3.16 addition to SignatureInformation.

[michaelpj]

I was having a look and it looks like lots of things in the list are done, sadly I can't check the checkboxes.

[jneira]

@michaelpj i suspected most of them was done too, what about copy it in a new comment and check what do you know about? I did that in #134 (comment)

[michaelpj]

I think it's almost all done! As far as I can see it's only some 3.16 things that are missing. Note that this is based on going through @jneira 's list not the full LSP changelog.

The remaining items are two substantial ones and one easy one:

• Call Hierarchy support, needed for New feature: call hierarchy support mpickering/ghcide#18
• Semantic Token support. Tracked with Add support for semantic highlighting (LSP 3.16) #240
• tags on SymbolInformation and DocumentSymbol (this is easy, I'll just do this one)

[michaelpj]

Oh, other things we're missing from 3.16:

• Monikers
• Linked editing
• Change annotations
• Locale
• Diagnostic data
• MessageActionItem additional properties
• create/rename/delete notifications
• normalizesLineEndings

[jneira]

We have semantic tokens support and call hierarchy!

[pranaysashank]

Since 3.16, there are new number types https://microsoft.github.io/language-server-protocol/specifications/specification-current/#number . We may want to provide newtype wrappers for them as using Int may lead to subtle bugs like haskell/haskell-language-server#2169

[michaelpj]

I'm going to try and update the checklist in the original description and remove the others!

[jneira]

I wonder if this list should be also placed in docs for reference, in the README?

[michaelpj]

I think if we were going to do that we'd want to actually list all the things we've implemented, which would be a bit tedious. I think it might be good to say which versions we have completely supported and which ones are partial, though.

[michaelpj]

Okay, main checklist should be up-to-date. I think we're actually doing pretty well: we're missing a few things from 3.16, but that's it.

[joyfulmantis]

We are also missing codeAction/resolve, which is new in 3.16. This is a blocker for implementing haskell/haskell-language-server#3534

[michaelpj]

We're generating the code from the metamodel now, so we should have full compliance with 3.17.