From d84009648e94417c351c2efcc2456f13bb185c90 Mon Sep 17 00:00:00 2001
From: rrrockey <126512405+rrrockey@users.noreply.github.com>
Date: Thu, 6 Mar 2025 05:46:37 -0600
Subject: [PATCH] refactor(server): replace switch statement in sendFile with
 Record lookup (#16630)

* refactor cache control handling in server/utils/file.ts

* add ability to null CacheControl.NONE

* Cache control handling comment

* Added comment to file.ts

This comment provides a better understanding of what the cacheControlHeader is doing.

* Update file.ts

Added comments

* Update server/src/utils/file.ts

* fix comments in file.ts

* run prettier with --write to fix formatting

---------

Co-authored-by: pnleguizamo <pnleguizamo@gmail.com>
Co-authored-by: drew-kearns <dkearns@iastate.edu>
Co-authored-by: Sierra (Izumi) Brown <119357873+SierraIBrown@users.noreply.github.com>
Co-authored-by: Alex <alex.tran1502@gmail.com>
---
 server/src/utils/file.ts | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/server/src/utils/file.ts b/server/src/utils/file.ts
index 915c60de2a..716e0b1957 100644
--- a/server/src/utils/file.ts
+++ b/server/src/utils/file.ts
@@ -33,27 +33,28 @@ export class ImmichFileResponse {
 type SendFile = Parameters<Response['sendFile']>;
 type SendFileOptions = SendFile[1];
 
+const cacheControlHeaders: Record<CacheControl, string | null> = {
+  [CacheControl.PRIVATE_WITH_CACHE]: 'private, max-age=86400, no-transform',
+  [CacheControl.PRIVATE_WITHOUT_CACHE]: 'private, no-cache, no-transform',
+  [CacheControl.NONE]: null, // falsy value to prevent adding Cache-Control header
+};
+
 export const sendFile = async (
   res: Response,
   next: NextFunction,
   handler: () => Promise<ImmichFileResponse>,
   logger: LoggingRepository,
 ): Promise<void> => {
+  // promisified version of 'res.sendFile' for cleaner async handling
   const _sendFile = (path: string, options: SendFileOptions) =>
     promisify<string, SendFileOptions>(res.sendFile).bind(res)(path, options);
 
   try {
     const file = await handler();
-    switch (file.cacheControl) {
-      case CacheControl.PRIVATE_WITH_CACHE: {
-        res.set('Cache-Control', 'private, max-age=86400, no-transform');
-        break;
-      }
-
-      case CacheControl.PRIVATE_WITHOUT_CACHE: {
-        res.set('Cache-Control', 'private, no-cache, no-transform');
-        break;
-      }
+    const cacheControlHeader = cacheControlHeaders[file.cacheControl];
+    if (cacheControlHeader) {
+      // set the header to Cache-Control
+      res.set('Cache-Control', cacheControlHeader);
     }
 
     res.header('Content-Type', file.contentType);
@@ -61,6 +62,7 @@ export const sendFile = async (
       res.header('Content-Disposition', `inline; filename*=UTF-8''${encodeURIComponent(file.fileName)}`);
     }
 
+    // configure options for serving
     const options: SendFileOptions = { dotfiles: 'allow' };
     if (!isAbsolute(file.path)) {
       options.root = process.cwd();