Live reloading of webapp resources broken

[timja]

Caused by #208

Picked up when updating theme plugins in jenkinsci/theme-manager-plugin#75

To reproduce:

Run this plugin:
https://github.com/jenkinsci/solarized-theme-plugin

Bump parent pom to 4.25

Run with mvn hpi:run
Configure the theme on system config page

Change a color, e.g. one in https://github.com/jenkinsci/solarized-theme-plugin/blob/master/src/main/webapp/solarized-dark.css#L3

Refresh the page.

It will get updated.

Bump parent pom to 4.26 (includes #208).

Repeat above, file won't be live reloaded

[sephiroth-j]

If you only run mvn clean hpi:run, the resource-path will still point to "src\main\webapp". If the output directory exists, e.g. after packaging, then the output directory will be used for resource-path. This is important to support webResources and its targetPath. In this case, the same structure of the final hpi package will be used to run the plugin locally. You can then edit the files in the output directory instead of the source directory and you will see the changes immediately (live reloading).

I am confident that there is another option instead of reverting #208. However, the decision is up to others.

It would certainly be possible to include the various directories of each webResource in the list of directories that are monitored for changes. The only thing I do not know yet is how to trigger the output directory update (packaging goal).

[timja]

If we can get something that works sanely then we don't need to revert it.

I don't think mvn clean hpi:run is a good solution though.

edit the files in the output directory

Aware, very poor developer UX though.

[jglick]

I am confident that there is another option instead of reverting #208.

Perhaps, but unless the fix is immediately apparent, we prefer to revert first and leave the amended feature implementation for some unspecified future time. Was there a particular plugin relying on this feature? First I had heard of it.

[timja]

Feel free to re-revert on top you can pin to current pom for now.

[sephiroth-j]

Was there a particular plugin relying on this feature? First I had heard of it.

Dependency-Track Plugin

[timja]

better to just use something like esbuild or webpack imo.

[jglick]

Yeah IIUC there are more standard ways of packaging JS libs in Jenkins plugins.