Add TIFF image conversion support to mg-assetscraper-db

TIFF is not on Ghost's media allow-list, so previously any .tif/.tiff
URLs were downloaded, identified as image/tiff, then silently dropped
because getFolderForMimeType returned null. Add image/tiff to
needsConverting so the existing sharp-based path re-encodes them to
lossless WebP, same as AVIF. The resulting file gets stored under
/content/images and the URL is rewritten in content.

Author: 55sketch

packages/mg-assetscraper-db/src/lib/AssetScraper.ts

@@ -725,7 +725,8 @@ export default class AssetScraper {
                 'image/svg+xml': 'svg',
                 'image/avif': 'avif',
                 'image/heif': 'heif',
-                'image/heic': 'heic'
+                'image/heic': 'heic',
+                'image/tiff': 'tif'
             };
             extension = mimeToExtMap[mimeType] || 'jpg';
         }

packages/mg-assetscraper-db/src/lib/utils.ts

@@ -10,10 +10,12 @@ const knownMediaTypes = ['video/mp4', 'video/webm', 'video/ogg', 'audio/mpeg', '
 const knownFileTypes = ['application/pdf', 'application/json', 'application/ld+json', 'application/vnd.oasis.opendocument.presentation', 'application/vnd.oasis.opendocument.spreadsheet', 'application/vnd.oasis.opendocument.text', 'application/vnd.ms-powerpoint', 'application/vnd.openxmlformats-officedocument.presentationml.presentation', 'application/rtf', 'text/plain', 'application/vnd.ms-excel', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet', 'application/xml', 'application/atom+xml'
 ];
 
-export const needsConverting = ['image/avif', 'image/heif', 'image/heic'];
+export const needsConverting = ['image/avif', 'image/heif', 'image/heic', 'image/tiff'];
 
 /**
- * Convert HEIC/HEIF/AVIF images to supported formats (JPEG or WebP)
+ * Convert HEIC/HEIF/AVIF/TIFF images to supported formats (JPEG or WebP).
+ * Ghost's media allow-list does not include TIFF, so we re-encode to WebP via
+ * sharp (libvips) the same way we do for AVIF.
  * @param buffer - The image buffer to convert
  * @param fileMime - The mime type of the image
  * @returns Object with converted buffer, extension, and mime type

packages/mg-assetscraper-db/src/test/AssetScraper.test.ts

@@ -29,13 +29,19 @@ describe('Asset Scraper', () => {
     }
     let avifImageBuffer: Buffer;
     let heicImageBuffer: Buffer;
+    let tiffImageBuffer: Buffer;
     let mp4VideoBuffer: Buffer;
     let mp3AudioBuffer: Buffer;
 
     before(async () => {
         jpgImageBuffer = await readFile(join(fixturesPath, '/image.jpg'));
         avifImageBuffer = await readFile(join(fixturesPath, '/image.avif'));
         heicImageBuffer = await readFile(join(fixturesPath, '/image.heic'));
+        // Generate a small TIFF fixture at runtime to avoid checking in a binary file
+        const sharp = (await import('sharp')).default;
+        tiffImageBuffer = await sharp({
+            create: {width: 8, height: 8, channels: 3, background: {r: 255, g: 0, b: 0}}
+        }).tiff().toBuffer();
         mp4VideoBuffer = await readFile(join(fixturesPath, '/video.mp4'));
         mp3AudioBuffer = await readFile(join(fixturesPath, '/audio.mp3'));
     });
@@ -559,6 +565,23 @@ describe('Asset Scraper', () => {
             assert.equal(responseData.extension, '.jpg');
         });
 
+        it('extractFileDataFromResponse tiff to webp', async () => {
+            const requestMock = nock('https://example.com')
+                .get('/assets/2025/03/photo.tif')
+                .reply(200, tiffImageBuffer);
+
+            const assetScraper = await createScraper({});
+
+            const response = await assetScraper.getRemoteMedia('https://example.com/assets/2025/03/photo.tif');
+            const responseData: any = await assetScraper.extractFileDataFromResponse('https://example.com/assets/2025/03/photo.tif', response);
+
+            assert.ok(requestMock.isDone());
+            assert.equal(responseData.fileBuffer.constructor.name, 'Buffer');
+            assert.equal(responseData.fileName, 'photo.webp');
+            assert.equal(responseData.fileMime, 'image/webp');
+            assert.equal(responseData.extension, '.webp');
+        });
+
         it('extractFileDataFromResponse falls back to content-type header and URL extension', async () => {
             const assetScraper = await createScraper({});