Do not send textDocument/didSave message if server does not declare its support (#14412)

Release Notes:

- Improved Zed logic for sending `textDocument/didSave` request
([14286](https://github.com/zed-industries/zed/issues/14286))

crates/lsp/src/lsp.rs

@@ -658,6 +658,10 @@ impl LanguageServer {
                         }),
                         ..SignatureHelpClientCapabilities::default()
                     }),
+                    synchronization: Some(TextDocumentSyncClientCapabilities {
+                        did_save: Some(true),
+                        ..TextDocumentSyncClientCapabilities::default()
+                    }),
                     ..TextDocumentClientCapabilities::default()
                 }),
                 experimental: Some(json!({

crates/project/src/project.rs

@@ -2547,7 +2547,12 @@ impl Project {
                 };
 
                 for (_, _, server) in self.language_servers_for_worktree(worktree_id) {
-                    let text = include_text(server.as_ref()).then(|| buffer.read(cx).text());
+                    if let Some(include_text) = include_text(server.as_ref()) {
+                        let text = if include_text {
+                            Some(buffer.read(cx).text())
+                        } else {
+                            None
+                        };
                         server
                             .notify::<lsp::notification::DidSaveTextDocument>(
                                 lsp::DidSaveTextDocumentParams {
@@ -2557,6 +2562,7 @@ impl Project {
                             )
                             .log_err();
                     }
+                }
 
                 for language_server_id in self.language_server_ids_for_buffer(buffer.read(cx), cx) {
                     self.simulate_disk_based_diagnostics_events_if_needed(language_server_id, cx);
@@ -11179,20 +11185,27 @@ impl Completion {
     }
 }
 
-fn include_text(server: &lsp::LanguageServer) -> bool {
+fn include_text(server: &lsp::LanguageServer) -> Option<bool> {
-    server
+    match server.capabilities().text_document_sync.as_ref()? {
-        .capabilities()
+        lsp::TextDocumentSyncCapability::Kind(kind) => match kind {
-        .text_document_sync
+            &lsp::TextDocumentSyncKind::NONE => None,
-        .as_ref()
+            &lsp::TextDocumentSyncKind::FULL => Some(true),
-        .and_then(|sync| match sync {
+            &lsp::TextDocumentSyncKind::INCREMENTAL => Some(false),
-            lsp::TextDocumentSyncCapability::Kind(_) => None,
+            _ => None,
-            lsp::TextDocumentSyncCapability::Options(options) => options.save.as_ref(),
+        },
-        })
+        lsp::TextDocumentSyncCapability::Options(options) => match options.save.as_ref()? {
-        .and_then(|save_options| match save_options {
+            lsp::TextDocumentSyncSaveOptions::Supported(supported) => {
-            lsp::TextDocumentSyncSaveOptions::Supported(_) => None,
+                if *supported {
-            lsp::TextDocumentSyncSaveOptions::SaveOptions(options) => options.include_text,
+                    Some(true)
-        })
+                } else {
-        .unwrap_or(false)
+                    None
+                }
+            }
+            lsp::TextDocumentSyncSaveOptions::SaveOptions(save_options) => {
+                Some(save_options.include_text.unwrap_or(false))
+            }
+        },
+    }
 }
 
 async fn load_direnv_environment(dir: &Path) -> Result<Option<HashMap<String, String>>> {

crates/project/src/project_tests.rs

@@ -322,6 +322,12 @@ async fn test_managing_language_servers(cx: &mut gpui::TestAppContext) {
                     trigger_characters: Some(vec![".".to_string(), "::".to_string()]),
                     ..Default::default()
                 }),
+                text_document_sync: Some(lsp::TextDocumentSyncCapability::Options(
+                    lsp::TextDocumentSyncOptions {
+                        save: Some(lsp::TextDocumentSyncSaveOptions::Supported(true)),
+                        ..Default::default()
+                    },
+                )),
                 ..Default::default()
             },
             ..Default::default()
@@ -336,6 +342,12 @@ async fn test_managing_language_servers(cx: &mut gpui::TestAppContext) {
                     trigger_characters: Some(vec![":".to_string()]),
                     ..Default::default()
                 }),
+                text_document_sync: Some(lsp::TextDocumentSyncCapability::Options(
+                    lsp::TextDocumentSyncOptions {
+                        save: Some(lsp::TextDocumentSyncSaveOptions::Supported(true)),
+                        ..Default::default()
+                    },
+                )),
                 ..Default::default()
             },
             ..Default::default()