DEV: Handle CORS and other fetch failures for media-optimization-worker (#15364)

Occasionally there will be a misconfigured CORS rule or a different
network failure when loading one of the media optimization WASM scripts.
This commit handles load failures and sends a new installFailed message
from the service worker, so that we don't error and hold up the rest
of the uploads if this occurs; the worker will just not process anything
and will keep trying to install itself with subsequent uploads until it succeeds.

This commit also removes the redundant useUppy variable in the worker
this should have been removed a while ago in f70e6c302f

app/assets/javascripts/discourse/app/services/media-optimization-worker.js

@@ -28,22 +28,21 @@ export default class MediaOptimizationWorkerService extends Service {
   promiseResolvers = null;
 
   async optimizeImage(data, opts = {}) {
-    this.usingUppy = data.id && data.id.includes("uppy");
     this.promiseResolvers = this.promiseResolvers || {};
     this.stopWorkerOnError = opts.hasOwnProperty("stopWorkerOnError")
       ? opts.stopWorkerOnError
       : true;
 
-    let file = this.usingUppy ? data : data.files[data.index];
+    let file = data;
     if (!/(\.|\/)(jpe?g|png|webp)$/i.test(file.type)) {
-      return this.usingUppy ? Promise.resolve() : data;
+      return Promise.resolve();
     }
     if (
       file.size <
       this.siteSettings
         .composer_media_optimization_image_bytes_optimization_threshold
     ) {
-      return this.usingUppy ? Promise.resolve() : data;
+      return Promise.resolve();
     }
     await this.ensureAvailiableWorker();
 
@@ -51,18 +50,14 @@ export default class MediaOptimizationWorkerService extends Service {
       this.logIfDebug(`Transforming ${file.name}`);
 
       this.currentComposerUploadData = data;
-      this.promiseResolvers[this.usingUppy ? file.id : file.name] = resolve;
+      this.promiseResolvers[file.id] = resolve;
 
       let imageData;
       try {
-        if (this.usingUppy) {
         imageData = await fileToImageData(file.data);
-        } else {
-          imageData = await fileToImageData(file);
-        }
       } catch (error) {
         this.logIfDebug(error);
-        return this.usingUppy ? resolve() : resolve(data);
+        return resolve();
       }
 
       this.worker.postMessage(
@@ -104,8 +99,9 @@ export default class MediaOptimizationWorkerService extends Service {
   }
 
   async install() {
-    this.installPromise = new Promise((resolve) => {
+    this.installPromise = new Promise((resolve, reject) => {
       this.afterInstalled = resolve;
+      this.failedInstall = reject;
       this.logIfDebug("Installing worker.");
       this.startWorker();
       this.registerMessageHandler();
@@ -152,13 +148,7 @@ export default class MediaOptimizationWorkerService extends Service {
             `Finished optimization of ${optimizedFile.name} new size: ${optimizedFile.size}.`
           );
 
-          if (this.usingUppy) {
           this.promiseResolvers[e.data.fileId](optimizedFile);
-          } else {
-            let data = this.currentComposerUploadData;
-            data.files[data.index] = optimizedFile;
-            this.promiseResolvers[optimizedFile.name](data);
-          }
 
           break;
         case "error":
@@ -170,20 +160,18 @@ export default class MediaOptimizationWorkerService extends Service {
             this.stopWorker();
           }
 
-          if (this.usingUppy) {
           this.promiseResolvers[e.data.fileId]();
-          } else {
-            this.promiseResolvers[e.data.fileName](
-              this.currentComposerUploadData
-            );
-          }
           break;
         case "installed":
           this.logIfDebug("Worker installed.");
           this.workerInstalled = true;
           this.afterInstalled();
-          this.afterInstalled = null;
+          this.cleanupInstallPromises();
-          this.installPromise = null;
+          break;
+        case "installFailed":
+          this.logIfDebug("Worker failed to install.");
+          this.failedInstall(e.data.errorMessage);
+          this.cleanupInstallPromises();
           break;
         default:
           this.logIfDebug(`Sorry, we are out of ${e}.`);
@@ -191,6 +179,12 @@ export default class MediaOptimizationWorkerService extends Service {
     };
   }
 
+  cleanupInstallPromises() {
+    this.afterInstalled = null;
+    this.failedInstall = null;
+    this.installPromise = null;
+  }
+
   logIfDebug(message) {
     if (this.siteSettings.composer_media_optimization_debug_mode) {
       // eslint-disable-next-line no-console

public/javascripts/media-optimization-worker.js

@@ -148,8 +148,12 @@ onmessage = async function (e) {
       }
       break;
     case "install":
+      try {
         await loadLibs(e.data.settings);
         postMessage({ type: "installed" });
+      } catch (error) {
+        postMessage({ type: "installFailed", errorMessage: error.message });
+      }
       break;
     default:
       logIfDebug(`Sorry, we are out of ${e}.`);