Merge pull request #6942 from video-dev/task/xhr-loader-replace-non-null-assertions

Replace non-null assertions in xhr-loader and gate evoking of loader callbacks

Author: robwalch

src/utils/fetch-loader.ts

@@ -93,8 +93,6 @@ class FetchLoader implements Loader<LoaderContext> {
     stats.loading.start = self.performance.now();
 
     const initParams = getRequestParameters(context, this.controller.signal);
-    const onProgress: LoaderOnProgress<LoaderContext> | undefined =
-      callbacks.onProgress;
     const isArrayBuffer = context.responseType === 'arraybuffer';
     const LENGTH = isArrayBuffer ? 'byteLength' : 'length';
     const { maxTimeToFirstByteMs, maxLoadTimeMs } = config.loadPolicy;
@@ -109,8 +107,10 @@ class FetchLoader implements Loader<LoaderContext> {
         ? maxTimeToFirstByteMs
         : maxLoadTimeMs;
     this.requestTimeout = self.setTimeout(() => {
-      this.abortInternal();
-      callbacks.onTimeout(stats, context, this.response);
+      if (this.callbacks) {
+        this.abortInternal();
+        this.callbacks.onTimeout(stats, context, this.response);
+      }
     }, config.timeout);
 
     const fetchPromise = isPromise(this.request)
@@ -127,8 +127,10 @@ class FetchLoader implements Loader<LoaderContext> {
         config.timeout = maxLoadTimeMs;
         this.requestTimeout = self.setTimeout(
           () => {
-            this.abortInternal();
-            callbacks.onTimeout(stats, context, this.response);
+            if (this.callbacks) {
+              this.abortInternal();
+              this.callbacks.onTimeout(stats, context, this.response);
+            }
           },
           maxLoadTimeMs - (first - stats.loading.start),
         );
@@ -145,6 +147,7 @@ class FetchLoader implements Loader<LoaderContext> {
 
         stats.total = getContentLength(response.headers) || stats.total;
 
+        const onProgress = this.callbacks?.onProgress;
         if (onProgress && Number.isFinite(config.highWaterMark)) {
           return this.loadProgressively(
             response,
@@ -184,11 +187,12 @@ class FetchLoader implements Loader<LoaderContext> {
           code: response.status,
         };
 
+        const onProgress = this.callbacks?.onProgress;
         if (onProgress && !Number.isFinite(config.highWaterMark)) {
           onProgress(stats, context, responseData, response);
         }
 
-        callbacks.onSuccess(loaderResponse, stats, context, response);
+        this.callbacks?.onSuccess(loaderResponse, stats, context, response);
       })
       .catch((error) => {
         self.clearTimeout(this.requestTimeout);
@@ -199,7 +203,7 @@ class FetchLoader implements Loader<LoaderContext> {
         // when destroying, 'error' itself can be undefined
         const code: number = !error ? 0 : error.code || 0;
         const text: string = !error ? null : error.message;
-        callbacks.onError(
+        this.callbacks?.onError(
           { code, text },
           context,
           error ? error.details : null,

src/utils/xhr-loader.ts

@@ -113,7 +113,7 @@ class XhrLoader implements Loader<LoaderContext> {
         })
         .catch((error: Error) => {
           // IE11 throws an exception on xhr.open if attempting to access an HTTP resource over HTTPS
-          this.callbacks!.onError(
+          this.callbacks?.onError(
             { code: xhr.status, text: error.message },
             context,
             xhr,
@@ -220,23 +220,16 @@ class XhrLoader implements Loader<LoaderContext> {
             stats.loaded = stats.total = len;
             stats.bwEstimate =
               (stats.total * 8000) / (stats.loading.end - stats.loading.first);
-            if (!this.callbacks) {
-              return;
-            }
-            const onProgress = this.callbacks.onProgress;
+            const onProgress = this.callbacks?.onProgress;
             if (onProgress) {
               onProgress(stats, context, data, xhr);
             }
-            if (!this.callbacks) {
-              return;
-            }
             const response: LoaderResponse = {
               url: xhr.responseURL,
               data: data,
               code: status,
             };
-
-            this.callbacks.onSuccess(response, stats, context, xhr);
+            this.callbacks?.onSuccess(response, stats, context, xhr);
             return;
           }
         }
@@ -254,7 +247,7 @@ class XhrLoader implements Loader<LoaderContext> {
           this.retry(retryConfig);
         } else {
           logger.error(`${status} while loading ${context.url}`);
-          this.callbacks!.onError(
+          this.callbacks?.onError(
             { code: status, text: xhr.statusText },
             context,
             xhr,