stable sort diagnostics to avoid flickering

helix-term/src/application.rs

@@ -771,7 +771,7 @@ impl Application {
                                         // Note: The `lsp::DiagnosticSeverity` enum is already defined in decreasing order
                                         params
                                             .diagnostics
-                                            .sort_unstable_by_key(|d| (d.severity, d.range.start));
+                                            .sort_by_key(|d| (d.severity, d.range.start));
                                     }
                                     for source in &lang_conf.persistent_diagnostic_sources {
                                         let new_diagnostics = params
@@ -812,9 +812,8 @@ impl Application {
 
                         // Sort diagnostics first by severity and then by line numbers.
                         // Note: The `lsp::DiagnosticSeverity` enum is already defined in decreasing order
-                        diagnostics.sort_unstable_by_key(|(d, server_id)| {
+                        diagnostics
-                            (d.severity, d.range.start, *server_id)
+                            .sort_by_key(|(d, server_id)| (d.severity, d.range.start, *server_id));
-                        });
 
                         if let Some(doc) = doc {
                             let diagnostic_of_language_server_and_not_in_unchanged_sources =

helix-view/src/document.rs

@@ -99,7 +99,6 @@ impl Serialize for Mode {
         serializer.collect_str(self)
     }
 }
-
 /// A snapshot of the text of a document that we want to write out to disk
 #[derive(Debug, Clone)]
 pub struct DocumentSavedEvent {
@@ -1321,7 +1320,7 @@ impl Document {
                 true
             });
 
-            self.diagnostics.sort_unstable_by_key(|diagnostic| {
+            self.diagnostics.sort_by_key(|diagnostic| {
                 (diagnostic.range, diagnostic.severity, diagnostic.provider)
             });
 
@@ -1911,9 +1910,8 @@ impl Document {
             });
         }
         self.diagnostics.extend(diagnostics);
-        self.diagnostics.sort_unstable_by_key(|diagnostic| {
+        self.diagnostics
-            (diagnostic.range, diagnostic.severity, diagnostic.provider)
+            .sort_by_key(|diagnostic| (diagnostic.range, diagnostic.severity, diagnostic.provider));
-        });
     }
 
     /// clears diagnostics for a given language server id if set, otherwise all diagnostics are cleared