fix: Update how wrapped functions are detected as native functions

package.json

@@ -77,14 +77,17 @@
   },
   "lint-staged": {
     "src/**/*.js": [
+      "eslint",
       "prettier --write",
       "git add"
     ],
     "test/**/*.js": [
+      "eslint",
       "prettier --write",
       "git add"
     ],
     "plugins/**/*.js": [
+      "eslint",
       "prettier --write",
       "git add"
     ]

src/raven.js

@@ -222,6 +222,9 @@ Raven.prototype = {
       TraceKit.report.subscribe(function() {
         self._handleOnErrorStackInfo.apply(self, arguments);
       });
+
+      self._patchFunctionToString();
+
       if (self._globalOptions.instrument && self._globalOptions.instrument.tryCatch) {
         self._instrumentTryCatch();
       }
@@ -378,6 +381,7 @@ Raven.prototype = {
   uninstall: function() {
     TraceKit.report.uninstall();
 
+    this._unpatchFunctionToString();
     this._restoreBuiltIns();
 
     Error.stackTraceLimit = this._originalErrorStackTraceLimit;
@@ -940,6 +944,25 @@ Raven.prototype = {
     });
   },
 
+  _patchFunctionToString: function() {
+    var self = this;
+    self._originalFunctionToString = Function.prototype.toString;
+    // eslint-disable-next-line no-extend-native
+    Function.prototype.toString = function() {
+      if (typeof this === 'function' && this.__raven__) {
+        return self._originalFunctionToString.apply(this.__orig_method__, arguments);
+      }
+      return self._originalFunctionToString.apply(this, arguments);
+    };
+  },
+
+  _unpatchFunctionToString: function() {
+    if (this._originalFunctionToString) {
+      // eslint-disable-next-line no-extend-native
+      Function.prototype.toString = this._originalFunctionToString;
+    }
+  },
+
   /**
      * Wrap timer functions and event targets to catch errors and provide
      * better metadata.

src/utils.js

@@ -357,6 +357,8 @@ function isSameStacktrace(stack1, stack2) {
 function fill(obj, name, replacement, track) {
   var orig = obj[name];
   obj[name] = replacement(orig);
+  obj[name].__raven__ = true;
+  obj[name].__orig_method__ = orig;
   if (track) {
     track.push([obj, name, orig]);
   }

test/integration/test.js

@@ -1254,6 +1254,46 @@ describe('integration', function() {
         }
       );
     });
+
+    it('should preserve native code detection compatibility', function(done) {
+      var iframe = this.iframe;
+
+      iframeExecute(
+        iframe,
+        done,
+        function() {
+          done();
+        },
+        function() {
+          assert.include(
+            Function.prototype.toString.call(window.setTimeout),
+            '[native code]'
+          );
+          assert.include(
+            Function.prototype.toString.call(window.setInterval),
+            '[native code]'
+          );
+          assert.include(
+            Function.prototype.toString.call(window.addEventListener),
+            '[native code]'
+          );
+          assert.include(
+            Function.prototype.toString.call(window.removeEventListener),
+            '[native code]'
+          );
+          assert.include(
+            Function.prototype.toString.call(window.requestAnimationFrame),
+            '[native code]'
+          );
+          if ('fetch' in window) {
+            assert.include(
+              Function.prototype.toString.call(window.fetch),
+              '[native code]'
+            );
+          }
+        }
+      );
+    });
   });
 
   describe('uninstall', function() {