pwa can't cache resource with space in url

[zh99998]

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[x] Bug report  
[ ] Performance issue
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/angular/angular/blob/master/CONTRIBUTING.md#question
[ ] Other... Please describe:

Current behavior

when where is a resources in assets directory, and filename includes space " ", the @angular/pwa service worker can't cache it correctly.

Expected behavior

Minimal reproduction of the problem with instructions

ng add @angular/pwa
put an image named "a b.jpg" in assets
reference it in html
ng build --prod

open it in browser
enable offline mode in chrome devtools
refresh page
it will got a 504.

What is the motivation / use case for changing the behavior?

Environment

Angular version: X.Y.Z


Browser:
- [x] Chrome (desktop) version 68
- [ ] Chrome (Android) version XX
- [ ] Chrome (iOS) version XX
- [ ] Firefox version XX
- [ ] Safari (desktop) version XX
- [ ] Safari (iOS) version XX
- [ ] IE version XX
- [ ] Edge version XX
 
For Tooling issues:
- Node version: XX  
- Platform:  

Others:

[gkalpak]

This is a valid issue. The problem is that in the config generator, we process the file paths as reported by the filesystem, but the URL can differ (due to URI encoding).

So, the generated ngsw.json has an entry for /assets/a b.png, but the SW tries to match it with a request for /assets/a%20b.png and fails.

[Ruud-cb]

Just a shoutout that this is still a problem.
Our team fixed it by using this in package.json:
"build:prod": "ng build --prod && npm run fix-ngsw",
"fix-ngsw": "shx sed -i \"([\\w\\)])( )([\\w\\(])\" '$1%20$3' dist/**/ngsw.json"

Using this and this dependency