Add classname to silent token renewal iframe HTML Element (#6960)

Author: lalimasharda

change/@azure-msal-browser-ab795cfe-4e94-4130-b525-1b73fdda6437.json

@@ -0,0 +1,7 @@
+{
+  "type": "patch",
+  "comment": "Add classname to silent token renewal iframe HTML element #6960",
+  "packageName": "@azure/msal-browser",
+  "email": "[email protected]",
+  "dependentChangeType": "patch"
+}

lib/msal-browser/src/interaction_handler/SilentHandler.ts

@@ -148,6 +148,7 @@ export class SilentHandler extends InteractionHandler {
     private createHiddenIframe(): HTMLIFrameElement {
         const authFrame = document.createElement("iframe");
 
+        authFrame.className = "msalSilentIframe";
         authFrame.style.visibility = "hidden";
         authFrame.style.position = "absolute";
         authFrame.style.width = authFrame.style.height = "0";

lib/msal-browser/test/interaction_handler/SilentHandler.spec.ts

@@ -262,4 +262,14 @@ describe("SilentHandler.ts Unit Tests", () => {
             }, 500);
         });
     });
+
+    describe("createHiddenIframe()", () => {
+        it("creates iframe HTML element with classname and src properties", () => {
+            const silentHandler = new SilentHandler(authCodeModule, browserStorage, defaultTokenRequest, browserRequestLogger, { navigateFrameWait: DEFAULT_IFRAME_TIMEOUT_MS, pollIntervalMilliseconds: DEFAULT_POLL_INTERVAL_MS }, performanceClient);
+            // @ts-ignore
+            const authFrame = silentHandler.createHiddenIframe();
+            expect(authFrame instanceof HTMLIFrameElement).toBe(true);
+            expect(authFrame.className).toEqual("msalSilentIframe");
+        });
+    })
 });