feat: implement app cache deletion

[alessio-perugini]

Introduce a cache clean <app-id> command to clean app cache. This implementation also tries to stop the related app if running. In case we do not care about that we can simply rm -rf .cache/*.

Super simple implementation. The stopping of an app could be opionionated, eager to see what you think. In case it's too much we can remove that logic and/or trigger it with a specific flag.

Closes #52

[lucarin91]

The stopping of an app could be opionionated, eager to see what you think. In case it's too much we can remove that logic and/or trigger it with a specific flag.

I think stopping the running app makes sense; otherwise, we could lose the ability to do that afterward. A potential alternative could be to refuse to remove the cache of a running app.
Maybe we should add a flag

• cache clean <app-id> fails if the app is running
• cache clean <app-id> --force stops the app and then deletes the cache

[lucarin91]

I also not sure if the command should be in the app sub-command, for instance

arduino-app-cli app clean-cache <app-id> [--force]

[mirkoCrobu]

I agree with @lucarin91 about the usage of the flag.
About the location can be under "app" or maybe under "system"?
arduino-app-cli system clean-cache <app-id>

[dido18]

I vote for the clean-cache under the app command.

arduino-app-cli app clean-cache <app-id>
``

[alessio-perugini]

While implementing the CLI subcommands I took inspiration from the arduino-cli. My idea was to have similar mapping to what our user based is used to.

However I also feel like that the cache/clean-cache could be implemented as a subcommand of the app. Probably would be easier to understand it's scope, can be a bit surprising to have a generic cache that, for now, only operates on app related stuff.

cache clean --force stops the app and then deletes the cache

@lucarin91 yeah I like that

[alessio-perugini]

I'll wait for you guys design decision about the CLI api, in the meantime I've pushed the proposal to introduce the --force flag.

As soon as you reach an agreement shoot me a comment and I'll apply the proposed changes, if any. 🤓

[mirkoCrobu]

@alessio-perugini Thinking about it again, arduino-app-cli app clean-cache <app-id> [--force] I agree with @lucarin91
The clean-cache is at the app level. System is too general.

[alessio-perugini]

@mirkoCrobu @lucarin91 137fcc3

[lucarin91]

I tested on the board and I found the two bugs in the comments below (1 of them was my fault 😄). After that, I think we could merge this. Thanks in advance.

[lucarin91]

Sorry, I forgot to add a nil check here 😮‍💨

Suggested change

	if runningApp.FullPath.EqualsTo(app.FullPath) {
	if runningApp != nil && runningApp.FullPath.EqualsTo(app.FullPath) {

[lucarin91]

This is an iterator, so you should consume it, otherwise it will not execute anything

Suggested change

	_ = StopAndDestroyApp(ctx, app)
	for range StopAndDestroyApp(ctx, app) {
	// just consume the iterator
	}