Handle JavaScript loaded in a blob

test/vendor/tracekit-parser.test.js

@@ -3,8 +3,18 @@
 
 var TraceKit = require('../../vendor/TraceKit/tracekit');
 var CapturedExceptions = require('./fixtures/captured-errors');
+var sinon = require('sinon');
+var xhr;
 
 describe('TraceKit', function() {
+  beforeEach(function() {
+    xhr = sinon.useFakeXMLHttpRequest();
+  });
+
+  afterEach(function() {
+    xhr.restore();
+  });
+
   describe('Parser', function() {
     it('should parse Safari 6 error', function() {
       var stackFrames = TraceKit.computeStackTrace(CapturedExceptions.SAFARI_6);

test/vendor/tracekit.test.js

@@ -4,6 +4,7 @@
 var TraceKit = require('../../vendor/TraceKit/tracekit');
 var utils = require('../../src/utils');
 var supportsErrorEvent = utils.supportsErrorEvent;
+var sinon = require('sinon');
 
 describe('TraceKit', function() {
   describe('stacktrace info', function() {
@@ -81,6 +82,52 @@ describe('TraceKit', function() {
       assert.equal(trace.stack[2].line, 26);
       assert.equal(trace.stack[2].column, 5);
     });
+
+    it('should update url based on sourcemap suffix in blob: based frames if full url available', function() {
+      var server = sinon.createFakeServer();
+      server.respondImmediately = true;
+      server.respondWith('GET', 'blob:http://localhost:8080/some-blob', [
+        200,
+        {'Content-Type': 'application/javascript'},
+        'just a random stream of bytes, as we care only about the sourcemaps suffix there\n' +
+          'oh, here it comes! //# sourceMappingURL=http://awesome.com/file.js.map'
+      ]);
+
+      var stack_str =
+        'Error: test\n' +
+        '    at Error (native)\n' +
+        '    at s (blob:http://localhost:8080/some-blob:31:29146)';
+
+      var mock_err = {stack: stack_str};
+      var trace = TraceKit.computeStackTrace.computeStackTraceFromStackProp(mock_err);
+
+      assert.equal(trace.stack[1].url, 'http://awesome.com/file.js');
+
+      server.restore();
+    });
+
+    it('should update url based on sourcemap suffix in blob: based frames if relative url available, by adding location.origin to it', function() {
+      var server = sinon.createFakeServer();
+      server.respondImmediately = true;
+      server.respondWith('GET', 'blob:http://localhost:8080/some-blob', [
+        200,
+        {'Content-Type': 'application/javascript'},
+        'just a random stream of bytes, as we care only about the sourcemaps suffix there\n' +
+          'oh, here it comes! //# sourceMappingURL=~/awesome.com/file.js.map'
+      ]);
+
+      var stack_str =
+        'Error: test\n' +
+        '    at Error (native)\n' +
+        '    at s (blob:http://localhost:8080/some-blob:31:29146)';
+
+      var mock_err = {stack: stack_str};
+      var trace = TraceKit.computeStackTrace.computeStackTraceFromStackProp(mock_err);
+
+      assert.equal(trace.stack[1].url, 'http://localhost:9876/awesome.com/file.js');
+
+      server.restore();
+    });
   });
 
   describe('.computeStackTrace', function() {

vendor/TraceKit/tracekit.js

@@ -30,10 +30,14 @@ var ERROR_TYPES_RE = /^(?:[Uu]ncaught (?:exception: )?)?(?:((?:Eval|Internal|Ran
 
 function getLocationHref() {
   if (typeof document === 'undefined' || document.location == null) return '';
-
   return document.location.href;
 }
 
+function getLocationOrigin() {
+  if (typeof document === 'undefined' || document.location == null) return '';
+  return document.location.origin;
+}
+
 /**
  * TraceKit.report: cross-browser processing of unhandled exceptions
  *
@@ -441,6 +445,44 @@ TraceKit.computeStackTrace = (function computeStackTraceWrapper() {
         element.func = UNKNOWN_FUNCTION;
       }
 
+      if (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
+        // in the browser console, but there has already been an error so that's not
+        // that much of an issue.
+        var xhr = new XMLHttpRequest();
+        xhr.open('GET', element.url, false);
+        xhr.send(null);
+
+        // If we failed to download the source, skip this patch
+        if (xhr.status === 200) {
+          var source = xhr.responseText || '';
+
+          // We trim the source down to the last 300 characters as sourceMappingURL is always at the end of the file.
+          // Why 300? To be in line with: https://github.com/getsentry/sentry/blob/4af29e8f2350e20c28a6933354e4f42437b4ba42/src/sentry/lang/javascript/processor.py#L164-L175
+          source = source.slice(-300);
+
+          // Now we dig out the source map URL
+          var sourceMaps = source.match(/\/\/# sourceMappingURL=(.*)$/);
+
+          // If we don't find a source map comment or we find more than one, continue on to the next element.
+          if (sourceMaps) {
+            var sourceMapAddress = sourceMaps[1];
+
+            // Now we check to see if it's a relative URL.
+            // If it is, convert it to an absolute one.
+            if (sourceMapAddress.charAt(0) === '~') {
+              sourceMapAddress = getLocationOrigin() + sourceMapAddress.slice(1);
+            }
+
+            // Now we strip the '.map' off of the end of the URL and update the
+            // element so that Sentry can match the map to the blob.
+            element.url = sourceMapAddress.slice(0, -4);
+          }
+        }
+      }
+
       stack.push(element);
     }