[PM-15065] Extension not loading when accessed via URL (#12160)

* add check for extension prefixes in the three major browsers.

- Firefox does not throw an error or receive the message. Adding checks for Safari and Chrome for safety if this functionality were to change.

* remove unneeded mock rejection

* move prefixes to dedicated array

* refactor protocol check to its own variable

apps/browser/src/autofill/services/autofill.service.spec.ts

@@ -241,6 +241,23 @@ describe("AutofillService", () => {
 
       expect(tracker.emissions[0]).toEqual([]);
     });
+
+    ["moz-extension://", "chrome-extension://", "safari-web-extension://"].forEach(
+      (extensionPrefix) => {
+        it(`returns an empty array when the tab.url starts with ${extensionPrefix}`, async () => {
+          const tracker = subscribeTo(
+            autofillService.collectPageDetailsFromTab$({
+              ...tab,
+              url: `${extensionPrefix}/3e42342/popup/index.html`,
+            }),
+          );
+
+          await tracker.pauseUntilReceived(1);
+
+          expect(tracker.emissions[0]).toEqual([]);
+        });
+      },
+    );
   });
 
   describe("loadAutofillScriptsOnInstall", () => {

apps/browser/src/autofill/services/autofill.service.ts

@@ -130,9 +130,16 @@ export default class AutofillService implements AutofillServiceInterface {
       pageDetailsFallback$.next([]);
     });
 
-    // Empty/New tabs do not have a URL.
-    // In Safari, `tabSendMessage` doesn't throw an error for this case. Fallback to the empty array to handle.
-    if (!tab.url) {
+    // Fallback to empty array when:
+    // - In Safari, `tabSendMessage` doesn't throw an error for this case.
+    // - When opening the extension directly via the URL, `tabSendMessage` doesn't always respond nor throw an error in FireFox.
+    //   Adding checks for the major 3 browsers here to be safe.
+    const urlHasBrowserProtocol = [
+      "moz-extension://",
+      "chrome-extension://",
+      "safari-web-extension://",
+    ].some((protocol) => tab.url.startsWith(protocol));
+    if (!tab.url || urlHasBrowserProtocol) {
       pageDetailsFallback$.next([]);
     }