Add session request expiry checks

js/background.js

@@ -1640,6 +1640,15 @@
       }
     }
 
+    libsession.Protocols.SessionProtocol.checkSessionRequestExpiry().catch(
+      e => {
+        window.log.error(
+          'Error occured which checking for session request expiry',
+          e
+        );
+      }
+    );
+
     storage.onready(async () => {
       idleDetector.start();
     });

ts/session/messages/outgoing/content/SessionRequestMessage.ts

@@ -17,6 +17,7 @@ interface SessionRequestParams extends MessageParams {
 }
 
 export class SessionRequestMessage extends ContentMessage {
+  public static readonly ttl = 4 * 24 * 60 * 60 * 1000; // 4 days
   private readonly preKeyBundle: PreKeyBundleType;
 
   constructor(params: SessionRequestParams) {
@@ -25,7 +26,7 @@ export class SessionRequestMessage extends ContentMessage {
   }
 
   public ttl(): number {
-    return 4 * 24 * 60 * 60 * 1000; // 4 days
+    return SessionRequestMessage.ttl;
   }
 
   protected getPreKeyBundleMessage(): SignalService.PreKeyBundleMessage {

ts/session/protocols/SessionProtocol.ts

@@ -12,7 +12,7 @@ interface StringToNumberMap {
 export class SessionProtocol {
   private static dbLoaded: Boolean = false;
   /**
-   * This map olds the sent session timestamps, i.e. session requests message effectively sent to the recipient.
+   * This map holds the sent session timestamps, i.e. session requests message effectively sent to the recipient.
    * It is backed by a database entry so it's loaded from db on startup.
    * This map should not be used directly, but instead through
    * `updateSendSessionTimestamp()`, or `hasSendSessionRequest()`
@@ -73,6 +73,29 @@ export class SessionProtocol {
     return pendingSend || hasSent;
   }
 
+  /**
+   * Checks to see if any outgoing session requests have expired and re-sends them again if they have.
+   */
+  public static async checkSessionRequestExpiry(): Promise<any> {
+    await this.fetchFromDBIfNeeded();
+
+    const now = Date.now();
+    const sentTimestamps = Object.entries(this.sentSessionsTimestamp);
+    const promises = sentTimestamps.map(async ([device, sent]) => {
+      const expireTime = sent + SessionRequestMessage.ttl;
+      // Check if we need to send a session request
+      if (now < expireTime) {
+        return;
+      }
+
+      // Unset the timestamp, so that if it fails to send in this function, it will be guaranteed to send later on.
+      await this.updateSentSessionTimestamp(device, undefined);
+      await this.sendSessionRequestIfNeeded(new PubKey(device));
+    });
+
+    return Promise.all(promises) as Promise<any>;
+  }
+
   /**
    * Triggers a SessionRequestMessage to be sent if:
    *   - we do not already have a session and

ts/test/session/protocols/SessionProtocol_test.ts

@@ -11,7 +11,7 @@ import { PubKey } from '../../../session/types';
 // tslint:disable-next-line: max-func-body-length
 describe('SessionProtocol', () => {
   const sandbox = sinon.createSandbox();
-  const ourNumber = 'ourNumber';
+  const ourNumber = TestUtils.generateFakePubKey();
   const pubkey = TestUtils.generateFakePubKey();
   let getItemById: sinon.SinonStub;
   let send: sinon.SinonStub;
@@ -51,7 +51,7 @@ describe('SessionProtocol', () => {
 
     getItemById = TestUtils.stubData('getItemById').resolves({ value: {} });
 
-    sandbox.stub(UserUtil, 'getCurrentDevicePubKey').resolves(ourNumber);
+    sandbox.stub(UserUtil, 'getCurrentDevicePubKey').resolves(ourNumber.key);
     send = sandbox.stub(MessageSender, 'send' as any);
     SessionProtocol.reset();
   });
@@ -99,6 +99,80 @@ describe('SessionProtocol', () => {
     });
   });
 
+  describe('checkSessionRequestExpiry', () => {
+    let clock: sinon.SinonFakeTimers;
+    let now: number;
+    let sendSessionRequestStub: sinon.SinonStub<
+      [SessionRequestMessage, PubKey],
+      Promise<void>
+    >;
+    beforeEach(() => {
+      now = Date.now();
+      clock = sandbox.useFakeTimers(now);
+
+      sendSessionRequestStub = sandbox
+        .stub(SessionProtocol, 'sendSessionRequest')
+        .resolves();
+    });
+
+    it('should not send a session request if none have expired', async () => {
+      getItemById.withArgs('sentSessionsTimestamp').resolves({
+        id: 'sentSessionsTimestamp',
+        value: {
+          [pubkey.key]: now,
+        },
+      });
+
+      // Set the time just before expiry
+      clock.tick(SessionRequestMessage.ttl - 100);
+
+      await SessionProtocol.checkSessionRequestExpiry();
+      expect(getItemById.calledWith('sentSessionsTimestamp'));
+      expect(sendSessionRequestStub.callCount).to.equal(0);
+    });
+
+    it('should send a session request if expired', async () => {
+      getItemById.withArgs('sentSessionsTimestamp').resolves({
+        id: 'sentSessionsTimestamp',
+        value: {
+          [pubkey.key]: now,
+        },
+      });
+
+      // Expire the request
+      clock.tick(SessionRequestMessage.ttl + 100);
+
+      await SessionProtocol.checkSessionRequestExpiry();
+      expect(getItemById.calledWith('sentSessionsTimestamp'));
+      expect(sendSessionRequestStub.callCount).to.equal(1);
+    });
+
+    it('should remove the old sent timestamp when expired', async () => {
+      getItemById.withArgs('sentSessionsTimestamp').resolves({
+        id: 'sentSessionsTimestamp',
+        value: {
+          [pubkey.key]: now,
+        },
+      });
+
+      // Remove this call from the equation
+      sandbox.stub(SessionProtocol, 'sendSessionRequestIfNeeded').resolves();
+
+      // Expire the request
+      clock.tick(SessionRequestMessage.ttl + 100);
+
+      await SessionProtocol.checkSessionRequestExpiry();
+      expect(getItemById.calledWith('sentSessionsTimestamp'));
+      expect(await SessionProtocol.hasSentSessionRequest(pubkey)).to.equal(
+        false,
+        'hasSentSessionRequest should return false.'
+      );
+      expect(SessionProtocol.getSentSessionsTimestamp()).to.not.have.property(
+        pubkey.key
+      );
+    });
+  });
+
   describe('onSessionEstablished', () => {
     beforeEach(async () => {
       // add an existing entry in the sentMap