From 7aab945a2199be06e20a35ec0d197fc817a48d9d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Donny/=EA=B0=95=EB=8F=99=EC=9C=A4?= <kdy1997.dev@gmail.com>
Date: Tue, 29 Oct 2024 11:53:29 +0900
Subject: [PATCH] perf(es): Cache `current_dir()` system calls (#9683)

**Description:**

Cache `current_dir()` system calls. Those are needless because we already cache `current_dir` in some places so it will break if the user changes cwd anyway.

**Related issue:**

 - https://github.com/swc-project/swc/issues/9601
---
 .changeset/silent-cows-brake.md          |  7 +++++++
 crates/swc/src/config/mod.rs             |  4 +++-
 crates/swc_common/src/plugin/metadata.rs | 12 +++++++++---
 3 files changed, 19 insertions(+), 4 deletions(-)
 create mode 100644 .changeset/silent-cows-brake.md

diff --git a/.changeset/silent-cows-brake.md b/.changeset/silent-cows-brake.md
new file mode 100644
index 00000000000..7e083c0549b
--- /dev/null
+++ b/.changeset/silent-cows-brake.md
@@ -0,0 +1,7 @@
+---
+swc: patch
+swc_common: patch
+swc_core: patch
+---
+
+perf(es): Cache `current_dir()` system calls
diff --git a/crates/swc/src/config/mod.rs b/crates/swc/src/config/mod.rs
index 39c2fd92956..7d60e2efba3 100644
--- a/crates/swc/src/config/mod.rs
+++ b/crates/swc/src/config/mod.rs
@@ -842,7 +842,9 @@ pub struct CallerOptions {
 
 #[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"))))]
 fn default_cwd() -> PathBuf {
-    ::std::env::current_dir().unwrap()
+    static CWD: Lazy<PathBuf> = Lazy::new(|| ::std::env::current_dir().unwrap());
+
+    CWD.clone()
 }
 
 /// `.swcrc` file
diff --git a/crates/swc_common/src/plugin/metadata.rs b/crates/swc_common/src/plugin/metadata.rs
index 2f608e714e8..a4d6ed7160f 100644
--- a/crates/swc_common/src/plugin/metadata.rs
+++ b/crates/swc_common/src/plugin/metadata.rs
@@ -1,5 +1,7 @@
 use std::env;
 
+use once_cell::sync::Lazy;
+
 use crate::collections::AHashMap;
 
 /// Indexable key to the metadata context for a transform plugin.
@@ -48,12 +50,16 @@ impl TransformPluginMetadataContext {
         env: String,
         experimental: Option<AHashMap<String, String>>,
     ) -> Self {
+        static CWD: Lazy<Option<String>> = Lazy::new(|| {
+            env::current_dir()
+                .map(|cwd| cwd.as_path().to_string_lossy().to_string())
+                .ok()
+        });
+
         TransformPluginMetadataContext {
             filename,
             env,
-            cwd: env::current_dir()
-                .map(|cwd| cwd.as_path().to_string_lossy().to_string())
-                .ok(),
+            cwd: CWD.clone(),
             experimental: experimental.unwrap_or_default(),
         }
     }