perf(language_server): avoid cloning on message conversion

crates/oxc_diagnostics/src/lib.rs

@@ -338,4 +338,9 @@ impl OxcDiagnostic {
     pub fn with_source_code<T: SourceCode + Send + Sync + 'static>(self, code: T) -> Error {
         Error::from(self).with_source_code(code)
     }
+
+    /// Consumes the diagnostic and returns the inner owned data.
+    pub fn inner_owned(self) -> OxcDiagnosticInner {
+        *self.inner
+    }
 }

crates/oxc_linter/src/lsp.rs

@@ -69,11 +69,13 @@ pub struct MessageWithPosition<'a> {
 // we assume that the fix offset will not exceed 2GB in either direction
 #[expect(clippy::cast_possible_truncation)]
 pub fn oxc_diagnostic_to_message_with_position<'a>(
-    diagnostic: &OxcDiagnostic,
+    diagnostic: OxcDiagnostic,
     source_text: &str,
     rope: &Rope,
 ) -> MessageWithPosition<'a> {
-    let labels = diagnostic.labels.as_ref().map(|labels| {
+    let inner = diagnostic.inner_owned();
+
+    let labels = inner.labels.as_ref().map(|labels| {
         labels
             .iter()
             .map(|labeled_span| {
@@ -89,56 +91,33 @@ pub fn oxc_diagnostic_to_message_with_position<'a>(
     });
 
     MessageWithPosition {
-        message: diagnostic.message.clone(),
-        severity: diagnostic.severity,
-        help: diagnostic.help.clone(),
-        url: diagnostic.url.clone(),
-        code: diagnostic.code.clone(),
+        message: inner.message,
+        severity: inner.severity,
+        help: inner.help,
+        url: inner.url,
+        code: inner.code,
         labels,
         fixes: PossibleFixesWithPosition::None,
     }
 }
 
-// clippy: the source field is checked and assumed to be less than 4GB, and
-// we assume that the fix offset will not exceed 2GB in either direction
-#[expect(clippy::cast_possible_truncation)]
 pub fn message_to_message_with_position<'a>(
-    message: &Message<'a>,
+    message: Message<'a>,
     source_text: &str,
     rope: &Rope,
 ) -> MessageWithPosition<'a> {
-    let labels = message.error.labels.as_ref().map(|labels| {
-        labels
-            .iter()
-            .map(|labeled_span| {
-                let offset = labeled_span.offset() as u32;
-                let start_position = offset_to_position(rope, offset, source_text);
-                let end_position =
-                    offset_to_position(rope, offset + labeled_span.len() as u32, source_text);
-                let message = labeled_span.label().map(|label| Cow::Owned(label.to_string()));
-
-                SpanPositionMessage::new(start_position, end_position).with_message(message)
-            })
-            .collect::<Vec<_>>()
-    });
-
-    MessageWithPosition {
-        message: message.error.message.clone(),
-        severity: message.error.severity,
-        help: message.error.help.clone(),
-        url: message.error.url.clone(),
-        code: message.error.code.clone(),
-        labels,
-        fixes: match &message.fixes {
-            PossibleFixes::None => PossibleFixesWithPosition::None,
-            PossibleFixes::Single(fix) => {
-                PossibleFixesWithPosition::Single(fix_to_fix_with_position(fix, rope, source_text))
-            }
-            PossibleFixes::Multiple(fixes) => PossibleFixesWithPosition::Multiple(
-                fixes.iter().map(|fix| fix_to_fix_with_position(fix, rope, source_text)).collect(),
-            ),
-        },
-    }
+    let mut result = oxc_diagnostic_to_message_with_position(message.error, source_text, rope);
+    result.fixes = match &message.fixes {
+        PossibleFixes::None => PossibleFixesWithPosition::None,
+        PossibleFixes::Single(fix) => {
+            PossibleFixesWithPosition::Single(fix_to_fix_with_position(fix, rope, source_text))
+        }
+        PossibleFixes::Multiple(fixes) => PossibleFixesWithPosition::Multiple(
+            fixes.iter().map(|fix| fix_to_fix_with_position(fix, rope, source_text)).collect(),
+        ),
+    };
+
+    result
 }
 
 #[derive(Debug)]

crates/oxc_linter/src/service/runtime.rs

@@ -729,7 +729,7 @@ impl Runtime {
                                         messages.lock().unwrap().extend(
                                             diagnostics.into_iter().map(|diagnostic| {
                                                 oxc_diagnostic_to_message_with_position(
-                                                    &diagnostic,
+                                                    diagnostic,
                                                     source_text,
                                                     rope,
                                                 )
@@ -754,7 +754,7 @@ impl Runtime {
                         messages.lock().unwrap().extend(section_messages.iter().map(|message| {
                             let message = message_cloner.clone_message(message);
 
-                            message_to_message_with_position(&message, source_text, rope)
+                            message_to_message_with_position(message, source_text, rope)
                         }));
                     },
                 );

crates/oxc_linter/src/tsgolint.rs

@@ -383,7 +383,7 @@ impl TsGoLintState {
 
                                             let mut message_with_position: MessageWithPosition<'_> =
                                                 message_to_message_with_position(
-                                                    &Message::from_tsgo_lint_diagnostic(
+                                                    Message::from_tsgo_lint_diagnostic(
                                                         tsgolint_diagnostic,
                                                         &source_text,
                                                     ),