refactor: use 'mime' package to determine a file's extension

package.json

@@ -62,6 +62,7 @@
     "formik": "^2.4.6",
     "gravatar-url": "3.1.0",
     "lodash": "4.17.21",
+    "mime": "3",
     "next": "^14.2.4",
     "node-cache": "5.1.2",
     "node-gyp": "9.3.1",
@@ -119,6 +120,7 @@
     "@types/express": "4.17.17",
     "@types/express-session": "1.17.6",
     "@types/lodash": "4.14.191",
+    "@types/mime": "3",
     "@types/node": "20.14.8",
     "@types/node-schedule": "2.1.0",
     "@types/nodemailer": "6.4.7",

pnpm-lock.yaml

@@ -98,6 +98,9 @@ importers:
       lodash:
         specifier: 4.17.21
         version: 4.17.21
+      mime:
+        specifier: '3'
+        version: 3.0.0
       next:
         specifier: ^14.2.4
         version: 14.2.4(@babel/core@7.24.7)(react-dom@18.3.1(react@18.3.1))(react@18.3.1)
@@ -264,6 +267,9 @@ importers:
       '@types/lodash':
         specifier: 4.14.191
         version: 4.14.191
+      '@types/mime':
+        specifier: '3'
+        version: 3.0.4
       '@types/node':
         specifier: 20.14.8
         version: 20.14.8
@@ -2848,6 +2854,9 @@ packages:
   '@types/mime@1.3.5':
     resolution: {integrity: sha512-/pyBZWSLD2n0dcHE3hq8s8ZvcETHtEuF+3E7XVt0Ig2nvsVQXdghHVcEkIWjy9A0wKfTn97a/PSDYohKIlnP/w==}
 
+  '@types/mime@3.0.4':
+    resolution: {integrity: sha512-iJt33IQnVRkqeqC7PzBHPTC6fDlRNRW8vjrgqtScAhrmMwe8c4Eo7+fUGTa+XdWrpEgpyKWMYmi2dIwMAYRzPw==}
+
   '@types/minimatch@3.0.5':
     resolution: {integrity: sha512-Klz949h02Gz2uZCMGwDUSDS1YBlTdDDgbWHi+81l29tQALUtvz4rAYi5uoVhE5Lagoq6DeqAUlbrHvW/mXDgdQ==}
 
@@ -10836,7 +10845,7 @@ snapshots:
       nopt: 5.0.0
       npmlog: 5.0.1
       rimraf: 3.0.2
-      semver: 7.6.2
+      semver: 7.3.8
       tar: 6.2.1
     transitivePeerDependencies:
       - encoding
@@ -10911,13 +10920,13 @@ snapshots:
   '@npmcli/fs@1.1.1':
     dependencies:
       '@gar/promisify': 1.1.3
-      semver: 7.6.2
+      semver: 7.3.8
     optional: true
 
   '@npmcli/fs@2.1.2':
     dependencies:
       '@gar/promisify': 1.1.3
-      semver: 7.6.2
+      semver: 7.3.8
 
   '@npmcli/move-file@1.1.2':
     dependencies:
@@ -12326,7 +12335,7 @@ snapshots:
       read-pkg: 5.2.0
       registry-auth-token: 5.0.2
       semantic-release: 19.0.5(encoding@0.1.13)
-      semver: 7.6.2
+      semver: 7.3.8
       tempy: 1.0.1
 
   '@semantic-release/release-notes-generator@10.0.3(semantic-release@19.0.5(encoding@0.1.13))':
@@ -12670,6 +12679,8 @@ snapshots:
 
   '@types/mime@1.3.5': {}
 
+  '@types/mime@3.0.4': {}
+
   '@types/minimatch@3.0.5': {}
 
   '@types/minimist@1.2.5': {}
@@ -12887,7 +12898,7 @@ snapshots:
       debug: 4.3.5(supports-color@8.1.1)
       globby: 11.1.0
       is-glob: 4.0.3
-      semver: 7.6.2
+      semver: 7.3.8
       tsutils: 3.21.0(typescript@4.9.5)
     optionalDependencies:
       typescript: 4.9.5
@@ -17269,7 +17280,7 @@ snapshots:
       nopt: 5.0.0
       npmlog: 6.0.2
       rimraf: 3.0.2
-      semver: 7.6.2
+      semver: 7.3.8
       tar: 6.2.1
       which: 2.0.2
     transitivePeerDependencies:
@@ -17348,7 +17359,7 @@ snapshots:
     dependencies:
       hosted-git-info: 4.1.0
       is-core-module: 2.14.0
-      semver: 7.6.2
+      semver: 7.3.8
       validate-npm-package-license: 3.0.4
 
   normalize-path@3.0.0: {}

server/lib/imageproxy.ts

@@ -3,6 +3,7 @@ import type { RateLimitOptions } from '@server/utils/rateLimit';
 import rateLimit from '@server/utils/rateLimit';
 import { createHash } from 'crypto';
 import { promises } from 'fs';
+import mime from 'mime/lite';
 import path, { join } from 'path';
 
 type ImageResponse = {
@@ -11,7 +12,7 @@ type ImageResponse = {
     curRevalidate: number;
     isStale: boolean;
     etag: string;
-    extension: string;
+    extension: string | null;
     cacheKey: string;
     cacheMiss: boolean;
   };
@@ -250,7 +251,7 @@ class ImageProxy {
       const arrayBuffer = await response.arrayBuffer();
       const buffer = Buffer.from(arrayBuffer);
 
-      const extension = this.getMimeExtension(
+      const extension = mime.getExtension(
         response.headers.get('content-type') ?? ''
       );
 
@@ -294,7 +295,7 @@ class ImageProxy {
 
   private async writeToCacheDir(
     dir: string,
-    extension: string,
+    extension: string | null,
     maxAge: number,
     expireAt: number,
     buffer: Buffer,
@@ -329,31 +330,6 @@ class ImageProxy {
   private getCacheDirectory() {
     return path.join(baseCacheDirectory, this.key);
   }
-
-  private getMimeExtension(mime: string): string {
-    switch (mime) {
-      case 'image/png':
-        return 'png';
-      case 'image/jpeg':
-        return 'jpeg';
-      case 'image/jpg':
-        return 'jpg';
-      case 'image/apng':
-        return 'apng';
-      case 'image/gif':
-        return 'gif';
-      case 'image/vnd.microsoft.icon':
-        return 'ico';
-      case 'image/tiff':
-        return 'tiff';
-      case 'image/webp':
-        return 'webp';
-      default:
-        break;
-    }
-
-    return '';
-  }
 }
 
 export default ImageProxy;