fix(ngMock): fix collecting stack trace in inject() on IE10+, PhantomJS

jurko-gospodnetic · gkalpak · commit 92c3b753d487 · 2016-04-09T20:49:10.000+03:00
Add support for collecting current stack trace information in browsers (e.g. IE10+, PhantomJS) that do not automatically store the current stack trace information in a newly created `Error` object's `stack` property, but only add it there once the `Error` gets thrown. The original implementation works fine in Firefox & Chrome, but fails on IE10+ and PhantomJS where it, for example, breaks Karma's error reporting in cases when an exception is thrown in a test like the following: ``` it('the holy crusade', inject(function() { var x = {}; x.holyGrail(); })); ``` In this case, the ngMock `inject()` implementation would incorrectly add the word `undefined` at the end of the collected error stack trace information, thus causing the main error description to be reported back to Karma as `undefined`. The added test makes sure this functionality: - works as expected in browsers supporting JavaScript stack trace collection, e.g. Chrome, Firefox, IE10+, Opera & PhantomJS - does not add any bogus stack track information in browsers that do not support JavaScript stack trace collection, e.g. IE9 Fixes angular#13591 Closes angular#13592 Closes angular#13593
diff --git a/src/ngMock/angular-mocks.js b/src/ngMock/angular-mocks.js
@@ -2916,6 +2916,12 @@ angular.mock.$RootScopeDecorator = ['$delegate', function($delegate) {
   window.inject = angular.mock.inject = function() {
     var blockFns = Array.prototype.slice.call(arguments, 0);
     var errorForStack = new Error('Declaration Location');
+    // IE10+ and PhanthomJS do not set stack trace information, until the error is thrown
+    if (!errorForStack.stack) {
+      try {
+        throw errorForStack;
+      } catch (e) {}
+    }
     return wasInjectorCreated() ? workFn.call(currentSpec) : workFn;
     /////////////////////
     function workFn() {
diff --git a/test/ngMock/angular-mocksSpec.js b/test/ngMock/angular-mocksSpec.js
@@ -914,6 +914,51 @@ describe('ngMock', function() {
           });
         }).toThrow('test message');
       }));
+
+      describe('error stack trace when called outside of spec context', function() {
+        // - Chrome, Firefox, Edge, Opera give us the stack trace as soon as an Error is created
+        // - IE10+, PhantomJS give us the stack trace only once the error is thrown
+        // - IE9 does not provide stack traces
+        var stackTraceSupported = (function() {
+          var error = new Error();
+          if (!error.stack) {
+            try {
+              throw error;
+            } catch (e) {}
+          }
+
+          return !!error.stack;
+        })();
+
+        function testCaller() {
+          return inject(function() {
+            throw new Error();
+          });
+        }
+        var throwErrorFromInjectCallback = testCaller();
+
+        if (stackTraceSupported) {
+          describe('on browsers supporting stack traces', function() {
+            it('should update thrown Error stack trace with inject call location', function() {
+              try {
+                throwErrorFromInjectCallback();
+              } catch (e) {
+                expect(e.stack).toMatch('testCaller');
+              }
+            });
+          });
+        } else {
+          describe('on browsers not supporting stack traces', function() {
+            it('should not add stack trace information to thrown Error', function() {
+              try {
+                throwErrorFromInjectCallback();
+              } catch (e) {
+                expect(e.stack).toBeUndefined();
+              }
+            });
+          });
+        }
+      });
     });
   });
 
