ref(replay): Add further logging to network body parsing (#9566)

We got somewhat closer to figuring out the problem there. Based on this
comment:
#9339 (comment)

> The requests are now showing with the request body, but the response
body is "undefined"

It seems that the problem is with parsing the response body for a XHR
request. I added some more logging there, to be able to debug this
further.

packages/replay/src/coreHandlers/util/networkUtils.ts

@@ -78,6 +78,8 @@ export function getBodyString(body: unknown): string | undefined {
     __DEBUG_BUILD__ && logger.warn('[Replay] Failed to serialize body', body);
   }
 
+  __DEBUG_BUILD__ && logger.info('[Replay] Skipping network body because of body type', body);
+
   return undefined;
 }
 

packages/replay/src/coreHandlers/util/xhrUtils.ts

@@ -135,15 +135,24 @@ function getResponseHeaders(xhr: XMLHttpRequest): Record<string, string> {
 }
 
 function _getXhrResponseBody(xhr: XMLHttpRequest): string | undefined {
+  // We collect errors that happen, but only log them if we can't get any response body
+  const errors: unknown[] = [];
+
   try {
     return xhr.responseText;
-  } catch {} // eslint-disable-line no-empty
+  } catch (e) {
+    errors.push(e);
+  }
 
   // Try to manually parse the response body, if responseText fails
   try {
     const response = xhr.response;
     return getBodyString(response);
-  } catch {} // eslint-disable-line no-empty
+  } catch (e) {
+    errors.push(e);
+  }
+
+  __DEBUG_BUILD__ && logger.warn('[Replay] Failed to get xhr response body', ...errors);
 
   return undefined;
 }