ref: Disable blob handling as its using deprecated sync XHR API

Author: kamilogorek

packages/browser/src/tracekit/index.js

@@ -38,11 +38,7 @@ var _is = require('@sentry/utils/is');
 var window =
   typeof window !== 'undefined'
     ? window
-    : typeof global !== 'undefined'
-      ? global
-      : typeof self !== 'undefined'
-        ? self
-        : {};
+    : typeof global !== 'undefined' ? global : typeof self !== 'undefined' ? self : {};
 
 var TraceKit = {};
 var _oldTraceKit = window.TraceKit;
@@ -635,7 +631,7 @@ TraceKit.computeStackTrace = (function computeStackTraceWrapper() {
       //   *before* the offending line.
       linesBefore = Math.floor(TraceKit.linesOfContext / 2),
       // Add one extra line if linesOfContext is odd
-      linesAfter = linesBefore + (TraceKit.linesOfContext % 2),
+      linesAfter = linesBefore + TraceKit.linesOfContext % 2,
       start = Math.max(0, line - linesBefore - 1),
       end = Math.min(source.length, line + linesAfter - 1);
 
@@ -759,11 +755,9 @@ TraceKit.computeStackTrace = (function computeStackTraceWrapper() {
 
     if (!(parts = codeRE.exec(code))) {
       re = new RegExp(escapeRegExp(code).replace(/\s+/g, '\\s+'));
-    }
-
-    // not sure if this is really necessary, but I don’t have a test
-    // corpus large enough to confirm that and it was in the original.
-    else {
+    } else {
+      // not sure if this is really necessary, but I don’t have a test
+      // corpus large enough to confirm that and it was in the original.
       var name = parts[1] ? '\\s+' + parts[1] : '',
         args = parts[2].split(',').join('\\s*,\\s*');
 
@@ -918,7 +912,12 @@ TraceKit.computeStackTrace = (function computeStackTraceWrapper() {
         element.func = guessFunctionName(element.url, element.line);
       }
 
-      if (element.url && element.url.substr(0, 5) === 'blob:') {
+      // NOTE: This feature has been turned off for now, as it produces deprecation warning
+      // due to usage of synchronous XMLHttpRequest. And because we use ReportingObserver API
+      // to report deprecations, we'd report ourselves...
+      // We can re-enable this feature once we migrate Tracekit to async-oriented code
+      // and we'll be able to await for the request to come back with the blob
+      if (false && element.url && element.url.substr(0, 5) === 'blob:') {
         // Special case for handling JavaScript loaded into a blob.
         // We use a synchronous AJAX request here as a blob is already in
         // memory - it's not making a network request.  This will generate a warning