feat(utils): Kill some dead code branches in XHR instrumentation (#4331)

Author: mitsuhiko

packages/utils/src/instrument.ts

@@ -226,15 +226,15 @@ function instrumentXHR(): void {
       // eslint-disable-next-line @typescript-eslint/no-this-alias
       const xhr = this;
       const url = args[1];
-      xhr.__sentry_xhr__ = {
+      const xhrInfo: SentryWrappedXMLHttpRequest['__sentry_xhr__'] = (xhr.__sentry_xhr__ = {
         // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
         method: isString(args[0]) ? args[0].toUpperCase() : args[0],
         url: args[1],
-      };
+      });
 
       // if Sentry key appears in URL, don't capture it as a request
       // eslint-disable-next-line @typescript-eslint/no-unsafe-member-access
-      if (isString(url) && xhr.__sentry_xhr__.method === 'POST' && url.match(/sentry_key/)) {
+      if (isString(url) && xhrInfo.method === 'POST' && url.match(/sentry_key/)) {
         xhr.__sentry_own_request__ = true;
       }
 
@@ -243,9 +243,7 @@ function instrumentXHR(): void {
           try {
             // touching statusCode in some platforms throws
             // an exception
-            if (xhr.__sentry_xhr__) {
-              xhr.__sentry_xhr__.status_code = xhr.status;
-            }
+            xhrInfo.status_code = xhr.status;
           } catch (e) {
             /* do nothing */
           }
@@ -256,8 +254,8 @@ function instrumentXHR(): void {
               // Make sure to pop both key and value to keep it in sync.
               requestKeys.splice(requestPos);
               const args = requestValues.splice(requestPos)[0];
-              if (xhr.__sentry_xhr__ && args[0] !== undefined) {
-                xhr.__sentry_xhr__.body = args[0] as XHRSendInput;
+              if (args[0] !== undefined) {
+                xhrInfo.body = args[0] as XHRSendInput;
               }
             }
           } catch (e) {