From be46f91d6261eb88b6e04364d912f6cb39b1a26c Mon Sep 17 00:00:00 2001
From: Qingyu Wang <40660121+colinaaa@users.noreply.github.com>
Date: Mon, 14 Jul 2025 20:09:32 +0800
Subject: [PATCH] perf(swc_error_reporters): avoid initilizing mitte handler
 when no diagnostics

---
 crates/swc_error_reporters/src/handler.rs | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/crates/swc_error_reporters/src/handler.rs b/crates/swc_error_reporters/src/handler.rs
index e28eb1f3dd21..5e1a87eed27f 100644
--- a/crates/swc_error_reporters/src/handler.rs
+++ b/crates/swc_error_reporters/src/handler.rs
@@ -87,10 +87,18 @@ impl ThreadSafetyDiagnostics {
         skip_filename: bool,
         color: ColorConfig,
     ) -> Vec<String> {
-        let handler = to_pretty_handler(color);
-        self.0
+        let diagnostics = self
+            .0
             .lock()
-            .expect("Failed to access the diagnostics lock")
+            .expect("Failed to access the diagnostics lock");
+
+        // If there are no diagnostics, return empty vector without initializing handler
+        if diagnostics.is_empty() {
+            return Vec::new();
+        }
+
+        let handler = to_pretty_handler(color);
+        diagnostics
             .iter()
             .map(|d| d.to_pretty_string(cm, skip_filename, &handler))
             .collect::<Vec<String>>()