Method checkForUpdate

packages/service-worker/worker/src/driver.ts:1053–1086

()

  }

  async checkForUpdate(): Promise<boolean> {
    let hash: string = '(unknown)';
    try {
      const manifest = await this.fetchLatestManifest(true);

      if (manifest === null) {
        // Client or server offline. Unable to check for updates at this time.
        // Continue to service clients (existing and new).
        this.debugger.log('Check for update aborted. (Client or server offline.)');
        return false;
      }

      hash = hashManifest(manifest);

      // Check whether this is really an update.
      if (this.versions.has(hash)) {
        await this.notifyClientsAboutNoNewVersionDetected(manifest, hash);
        return false;
      }

      await this.notifyClientsAboutVersionDetected(manifest, hash);

      await this.setupUpdate(manifest, hash);

      return true;
    } catch (err) {
      this.debugger.log(err as Error, `Error occurred while updating to manifest ${hash}`);

      this.state = DriverReadyState.EXISTING_CLIENTS_ONLY;
      this.stateMessage = `Degraded due to failed initialization: ${errorToString(err)}`;

      return false;
    }
  }

  /**
   * Synchronize the existing state to the underlying database.