From 126f187922b0a0a4c1335e044de0b5fc5b39f37b Mon Sep 17 00:00:00 2001
From: =?utf8?q?Magnus=20Gro=C3=9F?= <magnus@mggross.com>
Date: Fri, 2 Jun 2023 18:28:18 +0200
Subject: [PATCH] Add Ale integration support

Ale [0] is a famous plugin to show linter warnings and diagnostics. It
already provides extensive functionality and configurability to display
those diagnostics.
In order to allow diagnostics from other plugins (e.g. LSP plugins) to
be shown together with those linter warnings, Ale has API so that those
diagnostics can be sent to Ale.

Ale will then display them as if they came from Ale itself. This is
useful for many reasons, e.g. this ensures a consistent look and allows
the location list for a window to be populated with all diagnostics,
regardless from which plugin they come.

There are other famous LSP plugins, that already integrate with Ale,
e.g. coc.nvim [1] allows this with "diagnostic.displayByAle".

This patch implements the same functionality by adding an "aleSupport"
option that is off by default. If the option is turned on, diagnostics
will be sent to Ale instead of being displayed by this plugin directly.

[0] https://github.com/dense-analysis/ale
[1] https://github.com/neoclide/coc.nvim
---
 README.md                |  1 +
 autoload/lsp/diag.vim    | 32 +++++++++++++++++++++++++++++++-
 autoload/lsp/options.vim |  4 ++++
 doc/lsp.txt              |  5 +++++
 4 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 0c88aa5..892cc75 100644
--- a/README.md
+++ b/README.md
@@ -108,6 +108,7 @@ Some of the LSP plugin features can be enabled or disabled by using the LspOptio
 Here is an example of configuration with default values:
 ```viml
 call LspOptionsSet(#{
+	\   aleSupport: v:false,
 	\   autoComplete: v:true,
 	\   autoHighlight: v:false,
 	\   autoHighlightDiags: v:true,
diff --git a/autoload/lsp/diag.vim b/autoload/lsp/diag.vim
index ec3f971..e453dff 100644
--- a/autoload/lsp/diag.vim
+++ b/autoload/lsp/diag.vim
@@ -82,6 +82,10 @@ export def InitOnce()
   hlset([{name: 'LspDiagVirtualText', default: true, linksto: 'LineNr'}])
   prop_type_add('LspDiagVirtualText', {highlight: 'LspDiagVirtualText',
                                        override: true})
+
+  if opt.lspOptions.aleSupport
+    autocmd_add([{group: 'LspAleCmds', event: 'User', pattern: 'ALEWantResults', cmd: 'AleHook(g:ale_want_results_buffer)'}])
+  endif
 enddef
 
 # Sort diagnostics ascending based on line and character offset
@@ -235,6 +239,29 @@ def DiagsRefresh(bnr: number)
   signs->sign_placelist()
 enddef
 
+# Sends diagnostics to Ale
+def SendAleDiags(bnr: number, timerid: number)
+  if !diagsMap->has_key(bnr)
+    return
+  endif
+
+  # Conver to Ale's diagnostics format (:h ale-loclist-format)
+  ale#other_source#ShowResults(bnr, 'lsp', diagsMap[bnr].sortedDiagnostics->mapnew((_, v) => {
+     return {text: v.message,
+             lnum: v.range.start.line + 1,
+             col: util.GetLineByteFromPos(bnr, v.range.start) + 1,
+             end_lnum: v.range.end.line + 1,
+             end_col: util.GetLineByteFromPos(bnr, v.range.end) + 1,
+             type: "EWIH"[v.severity - 1]}
+  }))
+enddef
+
+# Hook called when Ale wants to retrieve new diagnostics
+def AleHook(bnr: number)
+  ale#other_source#StartChecking(bnr, 'lsp')
+  timer_start(0, function('SendAleDiags', [bnr]))
+enddef
+
 # New LSP diagnostic messages received from the server for a file.
 # Update the signs placed in the buffer for this file
 export def ProcessNewDiags(bnr: number)
@@ -242,7 +269,10 @@ export def ProcessNewDiags(bnr: number)
     DiagsUpdateLocList(bnr)
   endif
 
-  if !opt.lspOptions.autoHighlightDiags
+  if opt.lspOptions.aleSupport
+    SendAleDiags(bnr, -1)
+    return
+  elseif !opt.lspOptions.autoHighlightDiags
     return
   endif
 
diff --git a/autoload/lsp/options.vim b/autoload/lsp/options.vim
index 610631f..8ccf7e4 100644
--- a/autoload/lsp/options.vim
+++ b/autoload/lsp/options.vim
@@ -3,6 +3,10 @@ vim9script
 # LSP plugin options
 # User can override these by calling the OptionsSet() function.
 export var lspOptions: dict<any> = {
+  # Enable ale diagnostics support.
+  # If true, diagnostics will be sent to ale, which will be responsible for
+  # showing them.
+  aleSupport: false,
   # In insert mode, complete the current symbol automatically
   # Otherwise, use omni-completion
   autoComplete: true,
diff --git a/doc/lsp.txt b/doc/lsp.txt
index 19e8256..cb9fea6 100644
--- a/doc/lsp.txt
+++ b/doc/lsp.txt
@@ -412,6 +412,11 @@ Some of the LSP plugin features can be enabled or disabled by using the
 LspOptionsSet() function. This function accepts a dictionary argument with the
 following optional items:
 
+						*lsp-opt-aleSupport*
+aleSupport		|Boolean| option. If true, diagnostics will be sent to
+			Ale, instead of being displayed by this plugin.
+			This is useful to combine all LSP and linter
+			diagnostics. By default this is set to false.
 						*lsp-opt-autoComplete*
 autoComplete		|Boolean| option. In insert mode, automatically
 			complete the current symbol. Otherwise use
-- 
2.48.1