Strip metadata in the ExifTool worker during upload preview.

Cache stripped blobs, show original vs stripped metadata tabs, and keep user-facing errors on fixed store messages with console logging for diagnostics.

frontend/src/workers/exiftoolWorker.ts

@@ -1,9 +1,10 @@
 import zeroperlWasmUrl from '@6over3/zeroperl-ts/zeroperl.wasm?url';
-import { parseMetadata } from '@uswriting/exiftool';
+import { parseMetadata, writeMetadata } from '@uswriting/exiftool';
 import { EXIFTOOL_WORKER_INIT_JPEG } from '@/consts/exiftoolWorkerInitJpeg';
 import type { ExiftoolWorkerInMessage } from '@/types/workers/exiftoolWorkerInMessage';
 import type { ExiftoolWorkerJob } from '@/types/workers/exiftoolWorkerJob';
 import { resolveErrorMessage } from '@/utils/resolveErrorMessage';
+import { toArrayBuffer } from '@/utils/toArrayBuffer';
 
 /** Custom fetch function for `@uswriting/exiftool` to load `zeroperl.wasm` from the worker. */
 const exiftoolParseOptions = { fetch: () => fetch(zeroperlWasmUrl) };
@@ -107,17 +108,87 @@ const processJob = async (job: ExiftoolWorkerJob): Promise<void> => {
             const result = await parseMetadata(job.file, exiftoolParseOptions);
 
             if (!result.success) {
-                self.postMessage({ type: 'read-metadata-error', id: job.id, message: result.error });
+                const message = result.error ?? 'Could not load image metadata';
+
+                console.error('[exiftool-worker] read failed', { id: job.id, file: job.file.name, message });
+
+                self.postMessage({ type: 'read-metadata-error', id: job.id, message });
 
                 return;
             }
 
             self.postMessage({ type: 'read-metadata-done', id: job.id, output: result.data });
         } catch (error) {
+            const message = resolveErrorMessage(error, 'Could not load image metadata');
+
+            console.error('[exiftool-worker] read threw', { id: job.id, file: job.file.name, error });
+
             self.postMessage({
                 type: 'read-metadata-error',
                 id: job.id,
-                message: resolveErrorMessage(error, 'Could not load image metadata')
+                message
+            });
+        }
+
+        return;
+    }
+
+    if (job.type === 'strip-metadata') {
+        try {
+            await initializeWorker();
+
+            const result = await writeMetadata(
+                job.file,
+                {},
+                { args: ['-all='], ...exiftoolParseOptions }
+            );
+
+            if (!result.success) {
+                const message = result.error ?? 'Could not strip image metadata';
+
+                console.error('[exiftool-worker] strip failed', {
+                    id: job.id,
+                    file: job.file.name,
+                    type: job.file.type,
+                    exitCode: result.exitCode,
+                    message
+                });
+
+                self.postMessage({
+                    type: 'strip-metadata-error',
+                    id: job.id,
+                    message
+                });
+
+                return;
+            }
+
+            const data = toArrayBuffer(result.data);
+
+            if (!data) {
+                const message = 'Strip succeeded but returned no image bytes';
+
+                console.error('[exiftool-worker] strip missing data', {
+                    id: job.id,
+                    file: job.file.name,
+                    dataType: result.data === null ? 'null' : typeof result.data
+                });
+
+                self.postMessage({ type: 'strip-metadata-error', id: job.id, message });
+
+                return;
+            }
+
+            self.postMessage({ type: 'strip-metadata-done', id: job.id, data }, { transfer: [data] });
+        } catch (error) {
+            const message = resolveErrorMessage(error, 'Failed to strip metadata');
+
+            console.error('[exiftool-worker] strip failed', { id: job.id, file: job.file.name, error });
+
+            self.postMessage({
+                type: 'strip-metadata-error',
+                id: job.id,
+                message
             });
         }
     }
@@ -134,5 +205,11 @@ self.addEventListener('message', (event: MessageEvent<ExiftoolWorkerInMessage>)
 
     if (message.type === 'read-metadata') {
         enqueue({ type: 'read-metadata', id: message.id, file: message.file });
+
+        return;
+    }
+
+    if (message.type === 'strip-metadata') {
+        enqueue({ type: 'strip-metadata', id: message.id, file: message.file });
     }
 });