Merge pull request #4 from bengourley/null-caller

Handle case where function caller is null

Author: bengourley

karma.conf.js

@@ -6,7 +6,8 @@ module.exports = function (config) {
             'node_modules/stackframe/dist/stackframe.js',
             'stack-generator.js',
             'spec/spec-helper.js',
-            'spec/*-spec.js'
+            'spec/*-spec.js',
+            { pattern: 'spec/fixtures/**', included: false }
         ],
         reporters: ['spec'],
         port: 9876,

spec/fixtures/a.js

@@ -0,0 +1,5 @@
+function a () {
+  something_bad()
+}
+
+a()

spec/stack-generator-spec.js

@@ -1,5 +1,9 @@
 describe('StackGenerator', function() {
     describe('#backtrace', function() {
+        afterEach(function () {
+          window.onerror = null;
+        });
+
         it('should generate backtrace for function declarations', function() {
             var stackFrames = null;
 
@@ -88,5 +92,21 @@ describe('StackGenerator', function() {
             }
             expect(stackFrames[0].functionName).toBe('StackGenerator$$backtrace');
         });
+
+        it('should handle "null" callees', function(done) {
+          var errored = false;
+          window.onerror = function () {
+            try {
+              StackGenerator.backtrace();
+            } catch (e) {
+              errored = true;
+            }
+            expect(errored).toBe(false);
+            done();
+          }
+          var script = document.createElement('script');
+          script.src = '/base/spec/fixtures/a.js';
+          window.document.body.appendChild(script);
+        });
     });
 });

stack-generator.js

@@ -21,7 +21,7 @@
             }
 
             var curr = arguments.callee;
-            while (curr && stack.length < maxStackSize) {
+            while (curr && stack.length < maxStackSize && curr['arguments']) {
                 // Allow V8 optimizations
                 var args = new Array(curr['arguments'].length);
                 for (var i = 0; i < args.length; ++i) {