From 48b8620610f681a718872b58aafcda7aa56bb7e9 Mon Sep 17 00:00:00 2001
From: muxcmux <storm.bg@gmail.com>
Date: Wed, 31 Jan 2024 21:20:48 +0000
Subject: [PATCH] Fix handling of textDocument/diagnostic

The `textDocument` parameter for the `textDocument/diagnostic` request
is of type `TextDocumentIdentifier`, which has a single property `uri`
of type `DocumentUri`.

Ref: https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_diagnostic

According to the spec the `DocumentUri` type does not hold the contents
of the document, which the handler currently relies on in order to
publish diagnostics to the client.

This breaks the LSP mode in Neovim 0.10, which now supports pull
diagnostics, and possibly other editors too. The same problem exists in
`standardrb` (https://github.com/standardrb/standard/issues/575)

I have made the `textDocument/diagnostic` hander a no-op, since
diagnostics are already being pushed to clients on
`textDocument/didChange`.
---
 ...ix_handling_of_text_document_diagnostic.md |  1 +
 lib/rubocop/lsp/routes.rb                     |  4 +--
 spec/rubocop/lsp/server_spec.rb               | 32 ++-----------------
 3 files changed, 4 insertions(+), 33 deletions(-)
 create mode 100644 changelog/fix_handling_of_text_document_diagnostic.md

diff --git a/changelog/fix_handling_of_text_document_diagnostic.md b/changelog/fix_handling_of_text_document_diagnostic.md
new file mode 100644
index 000000000000..02a0e77cd60b
--- /dev/null
+++ b/changelog/fix_handling_of_text_document_diagnostic.md
@@ -0,0 +1 @@
+* [#12664](https://github.com/rubocop/rubocop/pull/12664): Fix handling of `textDocument/diagnostic`. ([@muxcmux][])
diff --git a/lib/rubocop/lsp/routes.rb b/lib/rubocop/lsp/routes.rb
index 8d7c40d08fda..27ba1fc4a328 100644
--- a/lib/rubocop/lsp/routes.rb
+++ b/lib/rubocop/lsp/routes.rb
@@ -73,9 +73,7 @@ def for(name)
       end
 
       handle 'textDocument/diagnostic' do |request|
-        doc = request[:params][:textDocument]
-        result = diagnostic(doc[:uri], doc[:text])
-        @server.write(result)
+        # no-op, diagnostics are handled in textDocument/didChange
       end
 
       handle 'textDocument/didChange' do |request|
diff --git a/spec/rubocop/lsp/server_spec.rb b/spec/rubocop/lsp/server_spec.rb
index 678d57738bf7..595a9ab2f1b7 100644
--- a/spec/rubocop/lsp/server_spec.rb
+++ b/spec/rubocop/lsp/server_spec.rb
@@ -103,10 +103,7 @@
         method: 'textDocument/diagnostic',
         params: {
           textDocument: {
-            languageId: 'ruby',
-            text: "def hi#{eol}  [1, 2,#{eol}   3  ]#{eol}end#{eol}",
-            uri: 'file:///path/to/file.rb',
-            version: 0
+            uri: 'file:///path/to/file.rb'
           }
         }
       ]
@@ -114,32 +111,7 @@
 
     it 'handles requests' do
       expect(stderr).to eq('')
-      expect(messages.count).to eq(1)
-      expect(messages.first).to eq(
-        jsonrpc: '2.0',
-        method: 'textDocument/publishDiagnostics',
-        params: {
-          diagnostics: [
-            {
-              code: 'Style/FrozenStringLiteralComment',
-              message: 'Missing frozen string literal comment.',
-              range: {
-                start: { character: 0, line: 0 }, end: { character: 0, line: 0 }
-              },
-              severity: 3,
-              source: 'rubocop'
-            }, {
-              code: 'Layout/SpaceInsideArrayLiteralBrackets',
-              message: 'Do not use space inside array brackets.',
-              range: {
-                start: { character: 4, line: 2 }, end: { character: 5, line: 2 }
-              },
-              severity: 3,
-              source: 'rubocop'
-            }
-          ], uri: 'file:///path/to/file.rb'
-        }
-      )
+      expect(messages.count).to eq(0)
     end
   end