fix: default fingerprinting when using synthetic stacktraces

When stracktrace:true is set via globalOptions there is an attempt to
create a default fingerprint value but it gets dropped from the request to
sentry. This ensures the fingerprint value is included in the data
sent to sentry.

src/raven.js

@@ -513,10 +513,11 @@ Raven.prototype = {
     }
 
     options = options || {};
+    msg = msg + ''; // Make sure it's actually a string
 
     var data = objectMerge(
       {
-        message: msg + '' // Make sure it's actually a string
+        message: msg
       },
       options
     );
@@ -555,11 +556,11 @@ Raven.prototype = {
     }
 
     if (this._globalOptions.stacktrace || (options && options.stacktrace)) {
+      // fingerprint on msg, not stack trace (legacy behavior, could be revisited)
+      data.fingerprint = data.fingerprint == null ? msg : data.fingerprint;
+
       options = objectMerge(
         {
-          // fingerprint on msg, not stack trace (legacy behavior, could be
-          // revisited)
-          fingerprint: msg,
           trimHeadFrames: 0
         },
         options
@@ -577,6 +578,13 @@ Raven.prototype = {
       };
     }
 
+    // Make sure that fingerprint is always wrapped in an array
+    if (data.fingerprint) {
+      data.fingerprint = isArray(data.fingerprint)
+        ? data.fingerprint
+        : [data.fingerprint];
+    }
+
     // Fire away!
     this._send(data);
 

test/raven.test.js

@@ -3044,6 +3044,19 @@ describe('Raven (public API)', function() {
         var frames = Raven._send.lastCall.args[0].stacktrace.frames;
         assertSynthetic(frames);
       });
+
+      it('should send a default fingerprint if stacktrace:true is set via globalOptions', function() {
+        this.sinon.stub(Raven, 'isSetup').returns(true);
+        this.sinon.stub(Raven, '_send');
+
+        Raven._globalOptions.stacktrace = true;
+        Raven.captureMessage('foo');
+
+        var fingerprint = Raven._send.lastCall.args[0].fingerprint;
+        // the fingerprint should be the same as the message
+        // but wrapped in an array
+        assert.deepEqual(fingerprint, ['foo']);
+      });
     });
   });