Revert "project: Handle textDocument/didSave and textDocument/didChange (un)registration and usage correctly (#36441)" (#36480)

This reverts commit c5991e74bb.

This PR broke rust-analyzer's check on save function, so reverting for
now

Release Notes:

- N/A

crates/lsp/src/lsp.rs

@@ -827,7 +827,7 @@ impl LanguageServer {
                     }),
                     synchronization: Some(TextDocumentSyncClientCapabilities {
                         did_save: Some(true),
-                        dynamic_registration: Some(true),
+                        dynamic_registration: Some(false),
                         ..TextDocumentSyncClientCapabilities::default()
                     }),
                     code_lens: Some(CodeLensClientCapabilities {

crates/project/src/lsp_store.rs

@@ -11820,28 +11820,8 @@ impl LspStore {
                         .transpose()?
                     {
                         server.update_capabilities(|capabilities| {
-                            let mut sync_options =
-                                Self::take_text_document_sync_options(capabilities);
-                            sync_options.change = Some(sync_kind);
                             capabilities.text_document_sync =
-                                Some(lsp::TextDocumentSyncCapability::Options(sync_options));
+                                Some(lsp::TextDocumentSyncCapability::Kind(sync_kind));
-                        });
-                        notify_server_capabilities_updated(&server, cx);
-                    }
-                }
-                "textDocument/didSave" => {
-                    if let Some(save_options) = reg
-                        .register_options
-                        .and_then(|opts| opts.get("includeText").cloned())
-                        .map(serde_json::from_value::<lsp::TextDocumentSyncSaveOptions>)
-                        .transpose()?
-                    {
-                        server.update_capabilities(|capabilities| {
-                            let mut sync_options =
-                                Self::take_text_document_sync_options(capabilities);
-                            sync_options.save = Some(save_options);
-                            capabilities.text_document_sync =
-                                Some(lsp::TextDocumentSyncCapability::Options(sync_options));
                         });
                         notify_server_capabilities_updated(&server, cx);
                     }
@@ -11993,19 +11973,7 @@ impl LspStore {
                 }
                 "textDocument/didChange" => {
                     server.update_capabilities(|capabilities| {
-                        let mut sync_options = Self::take_text_document_sync_options(capabilities);
+                        capabilities.text_document_sync = None;
-                        sync_options.change = None;
-                        capabilities.text_document_sync =
-                            Some(lsp::TextDocumentSyncCapability::Options(sync_options));
-                    });
-                    notify_server_capabilities_updated(&server, cx);
-                }
-                "textDocument/didSave" => {
-                    server.update_capabilities(|capabilities| {
-                        let mut sync_options = Self::take_text_document_sync_options(capabilities);
-                        sync_options.save = None;
-                        capabilities.text_document_sync =
-                            Some(lsp::TextDocumentSyncCapability::Options(sync_options));
                     });
                     notify_server_capabilities_updated(&server, cx);
                 }
@@ -12033,20 +12001,6 @@ impl LspStore {
 
         Ok(())
     }
-
-    fn take_text_document_sync_options(
-        capabilities: &mut lsp::ServerCapabilities,
-    ) -> lsp::TextDocumentSyncOptions {
-        match capabilities.text_document_sync.take() {
-            Some(lsp::TextDocumentSyncCapability::Options(sync_options)) => sync_options,
-            Some(lsp::TextDocumentSyncCapability::Kind(sync_kind)) => {
-                let mut sync_options = lsp::TextDocumentSyncOptions::default();
-                sync_options.change = Some(sync_kind);
-                sync_options
-            }
-            None => lsp::TextDocumentSyncOptions::default(),
-        }
-    }
 }
 
 // Registration with empty capabilities should be ignored.
@@ -13149,18 +13103,24 @@ async fn populate_labels_for_symbols(
 
 fn include_text(server: &lsp::LanguageServer) -> Option<bool> {
     match server.capabilities().text_document_sync.as_ref()? {
-        lsp::TextDocumentSyncCapability::Options(opts) => match opts.save.as_ref()? {
+        lsp::TextDocumentSyncCapability::Kind(kind) => match *kind {
-            // Server wants didSave but didn't specify includeText.
+            lsp::TextDocumentSyncKind::NONE => None,
-            lsp::TextDocumentSyncSaveOptions::Supported(true) => Some(false),
+            lsp::TextDocumentSyncKind::FULL => Some(true),
-            // Server doesn't want didSave at all.
+            lsp::TextDocumentSyncKind::INCREMENTAL => Some(false),
-            lsp::TextDocumentSyncSaveOptions::Supported(false) => None,
+            _ => None,
-            // Server provided SaveOptions.
+        },
+        lsp::TextDocumentSyncCapability::Options(options) => match options.save.as_ref()? {
+            lsp::TextDocumentSyncSaveOptions::Supported(supported) => {
+                if *supported {
+                    Some(true)
+                } else {
+                    None
+                }
+            }
             lsp::TextDocumentSyncSaveOptions::SaveOptions(save_options) => {
                 Some(save_options.include_text.unwrap_or(false))
             }
         },
-        // We do not have any save info. Kind affects didChange only.
-        lsp::TextDocumentSyncCapability::Kind(_) => None,
     }
 }