Make the DeviceListener listen to KeyBackupDecryptionKeyCached events (#32811)

Fixes #31916

apps/web/src/device-listener/DeviceListenerCurrentDevice.ts

@@ -94,6 +94,7 @@ export class DeviceListenerCurrentDevice {
         this.client.on(CryptoEvent.UserTrustStatusChanged, this.onUserTrustStatusChanged);
         this.client.on(CryptoEvent.KeysChanged, this.onCrossSigningKeysChanged);
         this.client.on(CryptoEvent.KeyBackupStatus, this.onKeyBackupStatusChanged);
+        this.client.on(CryptoEvent.KeyBackupDecryptionKeyCached, this.onKeyBackupDecryptionKeyCached);
         this.client.on(ClientEvent.AccountData, this.onAccountData);
         this.client.on(ClientEvent.Sync, this.onSync);
         this.client.on(RoomStateEvent.Events, this.onRoomStateEvents);
@@ -112,6 +113,7 @@ export class DeviceListenerCurrentDevice {
         this.client.removeListener(CryptoEvent.UserTrustStatusChanged, this.onUserTrustStatusChanged);
         this.client.removeListener(CryptoEvent.KeysChanged, this.onCrossSigningKeysChanged);
         this.client.removeListener(CryptoEvent.KeyBackupStatus, this.onKeyBackupStatusChanged);
+        this.client.removeListener(CryptoEvent.KeyBackupDecryptionKeyCached, this.onKeyBackupDecryptionKeyCached);
         this.client.removeListener(ClientEvent.AccountData, this.onAccountData);
         this.client.removeListener(ClientEvent.Sync, this.onSync);
         this.client.removeListener(RoomStateEvent.Events, this.onRoomStateEvents);
@@ -309,6 +311,12 @@ export class DeviceListenerCurrentDevice {
         this.deviceListener.recheck();
     };
 
+    private onKeyBackupDecryptionKeyCached = (): void => {
+        this.logger.info("Backup decryption key cached");
+        this.cachedKeyBackupUploadActive = undefined;
+        this.deviceListener.recheck();
+    };
+
     private onCrossSigningKeysChanged = (): void => {
         this.deviceListener.recheck();
     };

apps/web/test/unit-tests/DeviceListener-test.ts

@@ -161,6 +161,28 @@ describe("DeviceListener", () => {
             expect(unwatchSettingSpy).toHaveBeenCalled();
         });
 
+        it("responds to KeyBackupDecryptionKeyCached events", async () => {
+            // Given a Device Listener
+            const recheck = jest.fn();
+            const deviceListener = await createAndStart();
+            deviceListener.recheck = recheck;
+
+            // When a KeyBackupDecryptionKeyCached event happens
+            mockClient.emit(CryptoEvent.KeyBackupDecryptionKeyCached, "3");
+
+            // Then we rechecked the device information
+            expect(recheck).toHaveBeenCalled();
+
+            // And when we stop our device listener
+            const removeListener = jest.fn(() => {});
+            // @ts-ignore overwriting with a mock
+            mockClient.removeListener = removeListener;
+            deviceListener.stop();
+
+            // Then it should stop listening
+            expect(removeListener).toHaveBeenCalledWith(CryptoEvent.KeyBackupDecryptionKeyCached, expect.any(Function));
+        });
+
         describe("when device client information feature is enabled", () => {
             beforeEach(() => {
                 jest.spyOn(SettingsStore, "getValue").mockImplementation(