PWA not working with vite-based dev server

[ranma42]

Command

serve

Is this a regression?

• Yes, this behavior used to work in the previous version

The previous version in which this bug was not present was

Angular 16

Description

Serving a PWA with the default dev server is now broken.
Specifically, the vite dev server apparently mangles the files emitted by the previous build steps, but does not recompute the hashes stored in ngsw.json.
This results in the service worker being installed, but not really serving any file.

It is still possible to use the "old" (webpack-based) dev server that is apparently not affected by this.

Minimal Reproduction

Basically the steps are:

• create a new app ng new
• make it a PWA ng add @angular/pwa
• configure it to start the service worker in dev
• start it ng serve
• open it in the browser http://localhost:4200/ and wait a few seconds (so that the service worker can initialize)
• check the sw state at http://localhost:4200/ngsw/state

A full repo reproducing the issue is https://github.com/ranma42/pwa-repro
From this repo, the needed steps are:

• choose the commit to start from (ranma42/pwa-repro@a524b1a to check the issue with vite, ranma42/pwa-repro@6207a68 to compare with webpack)
• install the dependencies npm install
• start the server ng serve
• open the app in the browser http://localhost:4200/ and wait a few seconds (so that the service worker can initialize)
• check the sw state at http://localhost:4200/ngsw/state

Note that the repo contains both a revision that reproduces the issue and one that configures the build to use webpack for comparison, to show that in that case the dev server works as intended.
Also note that to properly check what is going on, you might want to clear the browser state by opening the inspector and (in Chrome-based browsers) going to Application -> Storage -> Clear site data

With the webpack dev server, http://localhost:4200/ngsw/state reports

NGSW Debug Info:

Driver version: 18.2.0
Driver state: NORMAL ((nominal))
Latest manifest hash: a9c562165e1a3b3bf67ea36a6e0537b1075767a8
Last update check: 38s35u

=== Version a9c562165e1a3b3bf67ea36a6e0537b1075767a8 ===

Clients: 946e5332-b1f0-466c-94fe-fac62101a798, 01aa5e79-986a-4910-bf75-eebbd80ad320

=== Idle Task Queue ===
Last update tick: 196u
Last update run: 27s738u
Task queue:


Debug log:

Exception or Error

For the vite devserver http://localhost:4200/ngsw/state reports

NGSW Debug Info:

Driver version: 18.2.0
Driver state: EXISTING_CLIENTS_ONLY (Degraded due to: Hash mismatch (cacheBustedFetchFromNetwork): http://localhost:4200/index.html: expected dcc35fd9e7cb2cbc5727f7dc941ab15beb5c8e94, got c628b20918af9ae65adf19ae7ef74c3c9d168ca7 (after cache busting)
Error: Hash mismatch (cacheBustedFetchFromNetwork): http://localhost:4200/index.html: expected dcc35fd9e7cb2cbc5727f7dc941ab15beb5c8e94, got c628b20918af9ae65adf19ae7ef74c3c9d168ca7 (after cache busting)
    at PrefetchAssetGroup.cacheBustedFetchFromNetwork (http://localhost:4200/ngsw-worker.js:476:21)
    at async PrefetchAssetGroup.fetchFromNetwork (http://localhost:4200/ngsw-worker.js:451:19)
    at async PrefetchAssetGroup.fetchAndCacheOnce (http://localhost:4200/ngsw-worker.js:430:21)
    at async http://localhost:4200/ngsw-worker.js:535:9
    at async http://localhost:4200/ngsw-worker.js:521:9
    at async http://localhost:4200/ngsw-worker.js:521:9
    at async http://localhost:4200/ngsw-worker.js:521:9
    at async http://localhost:4200/ngsw-worker.js:521:9
    at async PrefetchAssetGroup.initializeFully (http://localhost:4200/ngsw-worker.js:520:7)
    at async http://localhost:4200/ngsw-worker.js:924:11)
Latest manifest hash: 92656589d404e75dc7df6ccfe2840f76f7867faa
Last update check: 6s797u

=== Version 92656589d404e75dc7df6ccfe2840f76f7867faa ===

Clients: 

=== Idle Task Queue ===
Last update tick: 4s224u
Last update run: never
Task queue:
 * activate: cleanup-old-sw-caches
 * init post-load (cleanup)

Debug log:

[6s755u] Error(Hash mismatch (cacheBustedFetchFromNetwork): http://localhost:4200/index.html: expected dcc35fd9e7cb2cbc5727f7dc941ab15beb5c8e94, got c628b20918af9ae65adf19ae7ef74c3c9d168ca7 (after cache busting), Error: Hash mismatch (cacheBustedFetchFromNetwork): http://localhost:4200/index.html: expected dcc35fd9e7cb2cbc5727f7dc941ab15beb5c8e94, got c628b20918af9ae65adf19ae7ef74c3c9d168ca7 (after cache busting)
    at PrefetchAssetGroup.cacheBustedFetchFromNetwork (http://localhost:4200/ngsw-worker.js:476:21)
    at async PrefetchAssetGroup.fetchFromNetwork (http://localhost:4200/ngsw-worker.js:451:19)
    at async PrefetchAssetGroup.fetchAndCacheOnce (http://localhost:4200/ngsw-worker.js:430:21)
    at async http://localhost:4200/ngsw-worker.js:535:9
    at async http://localhost:4200/ngsw-worker.js:521:9
    at async http://localhost:4200/ngsw-worker.js:521:9
    at async http://localhost:4200/ngsw-worker.js:521:9
    at async http://localhost:4200/ngsw-worker.js:521:9
    at async PrefetchAssetGroup.initializeFully (http://localhost:4200/ngsw-worker.js:520:7)
    at async http://localhost:4200/ngsw-worker.js:924:11) initializeFully for 92656589d404e75dc7df6ccfe2840f76f7867faa

Your Environment

$ ng version

     _                      _                 ____ _     ___
    / \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|
   / △ \ | '_ \ / _` | | | | |/ _` | '__|   | |   | |    | |
  / ___ \| | | | (_| | |_| | | (_| | |      | |___| |___ | |
 /_/   \_\_| |_|\__, |\__,_|_|\__,_|_|       \____|_____|___|
                |___/


Angular CLI: 18.2.0
Node: 20.13.0
Package Manager: npm 10.5.2
OS: linux x64

Angular: 18.2.0
... animations, cli, common, compiler, compiler-cli, core, forms
... platform-browser, platform-browser-dynamic, router
... service-worker

Package                         Version
---------------------------------------------------------
@angular-devkit/architect       0.1802.0
@angular-devkit/build-angular   18.2.0
@angular-devkit/core            18.2.0
@angular-devkit/schematics      18.2.0
@schematics/angular             18.2.0
rxjs                            7.8.1
typescript                      5.5.4
zone.js                         0.14.10

Anything else relevant?

No response

[ranma42]

angular/angular#23613 is related: basically it covers all of the cases in which a proxy mangles the files, not just the mangling performed by the vite dev server. IIUC the conclusion is that the expected approach is to ensure that the file digests match those listed in ngsw.json; even though disabling the hash check has been proposed, it looks like it is considered too fragile.

[ranma42]

#28225 might be related

[alan-agius4]

The root cause of the issue is that Vite will transform all JS, CSS and HTML files during request time, this will cause of the hashes in the manifest to be invalid.