SwUpdate Methods lead to degraded Mode when service worker is stopped #32095
Description
🐞 bug report
Affected Package
The issue is caused by package @angular/service-worker
Is this a regression?
Probably not
Description
When SwUpdate::checkForUpdate() or SwUpdate::activateUpdate() is called while the service worker is stopped, the service worker enters a degraded state.
The likely cause is that the Driver is not initialized is this case. (Driver::initialize() is never called)
🔬 Minimal Reproduction
Reproduction is possible with the example code from the angular docs:
https://angular.io/guide/service-worker-communications
Just make sure that the service worker is stopped (by the browser after some idle time or manually with chrome dev tools) before the methods are called
🔥 Exception or Error
For checkForUpdates() this is the ngsw/state after the call:
NGSW Debug Info:
Driver state: EXISTING_CLIENTS_ONLY (Degraded due to failed initialization: Cannot read property 'previouslyCachedResources' of undefined
TypeError: Cannot read property 'previouslyCachedResources' of undefined
at Driver. (https://example.com/ngsw-worker.js:2624:32)
at Generator.next ()
at fulfilled (https://example.com/ngsw-worker.js:1787:62))
Latest manifest hash: none
🌍 Your Environment
Angular Version:
Angular CLI: 8.2.1
Node: 10.15.2
OS: linux x64
Angular: 8.2.1
... animations, cli, common, compiler, compiler-cli, core, forms
... language-service, platform-browser, platform-browser-dynamic
... router, service-worker
Package Version
-----------------------------------------------------------
@angular-devkit/architect 0.802.1
@angular-devkit/build-angular 0.802.1
@angular-devkit/build-optimizer 0.802.1
@angular-devkit/build-webpack 0.802.1
@angular-devkit/core 8.2.1
@angular-devkit/schematics 8.2.1
@angular/pwa 0.802.1
@ngtools/webpack 8.2.1
@schematics/angular 8.2.1
@schematics/update 0.802.1
rxjs 6.5.2
typescript 3.5.3
webpack 4.39.1
Browser:
Chromium 76.0.3809.87