Configure watch via .amber.yml

[anamba]

Description of the Change

Allow user to configure amber watch from .amber.yml. Configuring this way is optional (there is still a default config, and it is the same as before), and you can continue to use the command line switches if you want (if you have a config in .amber.yml, command line switches will override it).

A sample .amber.yml:

type: app
language: ecr
model: granite

# list of tasks to be run by `amber watch`
watch:
  # NOTE: names that match crystal commands are special (e.g. run, spec)
  run:
    # commands will be joined with && (join them yourself if need || or ;)
    build_commands:
      - mkdir -p bin
      - crystal build ./src/rcwebcr.cr -o bin/rcwebcr
    run_commands:
      - bin/rcwebcr
    include:
      - ./config/**/*.cr
      - ./src/**/*.cr
      - ./src/**/*.ecr
    exclude: # NOTE simplistic implementation: (1) enumerate all includes and excludes; (2) return (includes - excludes)
      - ./src/dont_restart_when_i_am_changed.cr
  spec:
    run_commands:
      - crystal spec
    include:
      - ./spec/**/*.cr
    exclude:
      - ./spec/dont_run_specs_when_i_am_changed.cr
  npm:
    build_commands:
      - npm install --loglevel=error
    run_commands:
      - npm run watch

Alternate Designs

The config is too complex to configure solely via command line switches/arguments, and leaving it non-user-configurable is creating unhappiness among users.

Benefits

Developers are now free to choose yarn over npm, or even nothing at all. Additionally, they can use amber watch to run other processes as well.

Possible Drawbacks

Mainly some code bloat. It's certainly possible that this is not something the amber project should handle directly.

[robacarp]

@anamba thanks for doing this, it's long overdue and will be a welcome change to the workflow.

It's certainly possible that this is not something the amber project should handle directly.

This is a great thing to discuss. Can you explain what you mean by that? Are there existing tools which Amber can wrap or depend on that you have experience with? I think previously Amber depended on another shard, which I believe was abandoned/absorbed.

[drujensen]

Excellent work. 🥇

[anamba]

This is a great thing to discuss. Can you explain what you mean by that? Are there existing tools which Amber can wrap or depend on that you have experience with? I think previously Amber depended on another shard, which I believe was abandoned/absorbed.

Nah, I didn't have anything in mind, I just mentioned that for the sake of completeness (answering the question).

I think you're referring to Sentry (which is still around). I saw some references to Sentry in there as I was working on this.

I do use Guardian for specs sometimes (but now that won't be necessary for amber projects). The main advantage provided by amber watch (with my changes) vs guardian is that it restarts the server process when it dies or fails to start properly (which for me, is surprisingly often, several times per work session... not sure if that's something to look into, or just one more weird Docker thing).

[faustinoaq]

@anamba Thanks you so much for this! 💯

I think we should document this here: https://docs.amberframework.org/amber/cli/watch

Related issue: amberframework/docs#121