fix(ngMock window.inject): Remove Error 'stack' property changes

wizardwerdna · vojtajina · commit 7e916455b36d · 2014-01-06T17:47:06.000-08:00
Recent browsers, particularly PhantomJS 1.9.2 and Safari 7.0
treat the stack property as non-configurable and unwritable.

Because window.inject captures the stack at the time of the inject,
and attempts to insert it into a captured throw from the injected
function by modifying e.stack, a meaningless error message and
stack is thrown instead.

This commit inserts two tests exposing the problem, and implements
a proposed solution that builds a new error-like object that mimicks
the old Error object, but with the additional stack information, and
captures the toString function from the Error object prototype.  This
appears to work for the browsers suppoerted here.
diff --git a/src/ngMock/angular-mocks.js b/src/ngMock/angular-mocks.js
@@ -2079,6 +2079,20 @@ if(window.jasmine || window.mocha) {
    *
    * @param {...Function} fns any number of functions which will be injected using the injector.
    */
+
+
+
+  var ErrorAddingDeclarationLocationStack = function(e, errorForStack) {
+    this.message = e.message;
+    this.name = e.name;
+    if (e.line) this.line = e.line;
+    if (e.sourceId) this.sourceId = e.sourceId;
+    if (e.stack && errorForStack)
+      this.stack = e.stack + '\n' + errorForStack.stack;
+    if (e.stackArray) this.stackArray = e.stackArray;
+  };
+  ErrorAddingDeclarationLocationStack.prototype.toString = Error.prototype.toString;
+
   window.inject = angular.mock.inject = function() {
     var blockFns = Array.prototype.slice.call(arguments, 0);
     var errorForStack = new Error('Declaration Location');
@@ -2099,7 +2113,9 @@ if(window.jasmine || window.mocha) {
           injector.invoke(blockFns[i] || angular.noop, this);
           /* jshint +W040 */
         } catch (e) {
-          if(e.stack && errorForStack) e.stack +=  '\n' + errorForStack.stack;
+          if (e.stack && errorForStack) {
+            throw new ErrorAddingDeclarationLocationStack(e, errorForStack);
+          }
           throw e;
         } finally {
           errorForStack = null;
diff --git a/test/ngMock/angular-mocksSpec.js b/test/ngMock/angular-mocksSpec.js
@@ -862,6 +862,23 @@ describe('ngMock', function() {
           expect(log).toEqual('module;inject;')
         });
       });
+
+      // We don't run the following tests on IE8.
+      // IE8 throws "Object does not support this property or method." error,
+      // when thrown from a function defined on window (which `inject` is).
+      if (msie <= 8) return;
+
+      it('should not change thrown Errors', function() {
+        expect(function(){
+          throw new Error('test message');
+        }).toThrow('test message');
+      });
+
+      it('should not change thrown strings', function(){
+        expect(function(){
+          throw 'test message';
+        }).toThrow('test message');
+      });
     });
   });
 
