Utils: add isSafeFrameWindow(), canAccessWindowTop()

src/utils.js

@@ -41,6 +41,7 @@ export const internal = {
   createTrackPixelIframeHtml,
   getWindowSelf,
   getWindowTop,
+  canAccessWindowTop,
   getWindowLocation,
   insertUserSyncIframe,
   insertElement,
@@ -180,6 +181,16 @@ export function getWindowLocation() {
   return window.location;
 }
 
+export function canAccessWindowTop() {
+  try {
+    if (internal.getWindowTop().location.href) {
+      return true;
+    }
+  } catch (e) {
+    return false;
+  }
+}
+
 /**
  * Wrappers to console.(log | info | warn | error). Takes N arguments, the same as the native methods
  */
@@ -620,6 +631,18 @@ export function inIframe() {
   }
 }
 
+/**
+ * https://iabtechlab.com/wp-content/uploads/2016/03/SafeFrames_v1.1_final.pdf
+ */
+export function isSafeFrameWindow() {
+  if (!inIframe()) {
+    return false;
+  }
+
+  const ws = internal.getWindowSelf();
+  return !!(ws.$sf && ws.$sf.ext);
+}
+
 export function isSafariBrowser() {
   return /^((?!chrome|android|crios|fxios).)*safari/i.test(navigator.userAgent);
 }

test/spec/utils_spec.js

@@ -21,6 +21,46 @@ describe('Utils', function () {
     type_array = 'Array',
     type_function = 'Function';
 
+  describe('canAccessWindowTop', function () {
+    it('should return true if window.top is accessible', function () {
+      assert.equal(utils.canAccessWindowTop(), true);
+    });
+
+    it('should return false if window.top is not accessible', function () {
+      const stubGetWindowTop = sinon.stub(utils.internal, 'getWindowTop').throws();
+      assert.equal(utils.canAccessWindowTop(), false);
+      stubGetWindowTop.restore();
+    });
+  });
+
+  describe('isSafeFrameWindow', function () {
+    // SafeFrames implementation
+    // https://iabtechlab.com/wp-content/uploads/2016/03/SafeFrames_v1.1_final.pdf
+    const $sf = {
+      ext: {
+        geom: function() {}
+      }
+    };
+
+    afterEach(function() {
+      delete window.$sf;
+    })
+
+    it('should return true if window.$sf is accessible', function () {
+      window.$sf = $sf;
+      assert.equal(utils.isSafeFrameWindow(), true);
+    });
+
+    it('should return false if window.$sf is missimplemented', function () {
+      window.$sf = {};
+      assert.equal(utils.isSafeFrameWindow(), false);
+    });
+
+    it('should return false if window.$sf is missing', function () {
+      assert.equal(utils.isSafeFrameWindow(), false);
+    });
+  });
+
   describe('getBidIdParameter', function () {
     it('should return value of the key in input object', function () {
       var obj = {