From cfb0666bf75d72c083e438440009b3c92a61a653 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Sat, 2 May 2026 07:54:00 +0000
Subject: [PATCH] refactor: pass encoding to readFileSync instead of toString

Pass the 'utf8' encoding directly to `fs.readFileSync` to avoid
intermediate Buffer allocation, reducing memory footprint and GC churn
during build/config processes.

Co-authored-by: vishnu-madhavan-git <237662584+vishnu-madhavan-git@users.noreply.github.com>
---
 packages/@expo/cli/src/utils/mergeGitIgnorePaths.ts      | 4 ++--
 packages/@expo/config-plugins/src/android/Package.ts     | 4 ++--
 packages/expo-brownfield/plugin/src/common/filesystem.ts | 9 +++++----
 3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/packages/@expo/cli/src/utils/mergeGitIgnorePaths.ts b/packages/@expo/cli/src/utils/mergeGitIgnorePaths.ts
index dab487df678413..8fe635d49973c9 100644
--- a/packages/@expo/cli/src/utils/mergeGitIgnorePaths.ts
+++ b/packages/@expo/cli/src/utils/mergeGitIgnorePaths.ts
@@ -35,8 +35,8 @@ export function mergeGitIgnorePaths(
     return null;
   }
 
-  const targetGitIgnore = fs.readFileSync(targetGitIgnorePath).toString();
-  const sourceGitIgnore = fs.readFileSync(sourceGitIgnorePath).toString();
+  const targetGitIgnore = fs.readFileSync(targetGitIgnorePath, 'utf8');
+  const sourceGitIgnore = fs.readFileSync(sourceGitIgnorePath, 'utf8');
   const merged = mergeGitIgnoreContents(targetGitIgnore, sourceGitIgnore);
   // Only rewrite the file if it was modified.
   if (merged.contents) {
diff --git a/packages/@expo/config-plugins/src/android/Package.ts b/packages/@expo/config-plugins/src/android/Package.ts
index 96222ebf4ba553..052004d5ed719e 100644
--- a/packages/@expo/config-plugins/src/android/Package.ts
+++ b/packages/@expo/config-plugins/src/android/Package.ts
@@ -125,7 +125,7 @@ export async function renameJniOnDiskForType({
   filesToUpdate.forEach((filepath: string) => {
     try {
       if (fs.lstatSync(filepath).isFile() && ['.h', '.cpp'].includes(path.extname(filepath))) {
-        let contents = fs.readFileSync(filepath).toString();
+        let contents = fs.readFileSync(filepath, 'utf8');
         contents = contents.replace(
           new RegExp(transformJavaClassDescriptor(currentPackageName).replace(/\//g, '\\/'), 'g'),
           transformJavaClassDescriptor(packageName)
@@ -207,7 +207,7 @@ export async function renamePackageOnDiskForType({
   filesToUpdate.forEach((filepath: string) => {
     try {
       if (fs.lstatSync(filepath).isFile()) {
-        let contents = fs.readFileSync(filepath).toString();
+        let contents = fs.readFileSync(filepath, 'utf8');
         if (path.extname(filepath) === '.kt') {
           contents = replacePackageName(contents, currentPackageName, kotlinSanitizedPackageName);
         } else {
diff --git a/packages/expo-brownfield/plugin/src/common/filesystem.ts b/packages/expo-brownfield/plugin/src/common/filesystem.ts
index dfbcceaeb05b2d..a1f9762a7c0c0c 100644
--- a/packages/expo-brownfield/plugin/src/common/filesystem.ts
+++ b/packages/expo-brownfield/plugin/src/common/filesystem.ts
@@ -26,13 +26,14 @@ const maybeReadOverwrittenTemplate = (template: string, platform?: PlatformStrin
   try {
     accessSync(path.join(process.cwd(), '.brownfield-templates'));
     if (existsSync(path.join(process.cwd(), '.brownfield-templates', template))) {
-      return readFileSync(path.join(process.cwd(), '.brownfield-templates', template)).toString();
+      return readFileSync(path.join(process.cwd(), '.brownfield-templates', template), 'utf8');
     }
 
     if (existsSync(path.join(process.cwd(), '.brownfield-templates', platform ?? '.', template))) {
       return readFileSync(
-        path.join(process.cwd(), '.brownfield-templates', platform ?? '.', template)
-      ).toString();
+        path.join(process.cwd(), '.brownfield-templates', platform ?? '.', template),
+        'utf8'
+      );
     }
     // eslint-disable-next-line no-empty
   } catch {}
@@ -55,7 +56,7 @@ const readTemplate = (template: string, platform?: PlatformString): string => {
     throw new Error(`Template ${template} doesn't exist at ${templatePath}`);
   }
 
-  return readFileSync(templatePath).toString();
+  return readFileSync(templatePath, 'utf8');
 };
 
 const createFileFromTemplateInternal = (