add esbuild config to CLI build and dev

[thedavidprice]

Closes #2069

@peterp decided to keep it simple for this one and go with:

[experimental]
     esbuild = false

What say you?

[peterp]

LGTM, do you want to add it to the redwood.toml file?

[peterp]

I've added a suggestion to make it evaluate the default value when the command is executed.

There are also some formatting warnings.

[pdjota]

@thedavidprice probably would help updating the documentation on the feature https://github.com/redwoodjs/redwoodjs.com/pull/703

[thedavidprice]

@peterp

1. Add to CRWA Template redwood.toml

Yes, I think that's a good idea.

• informs people about experimental features
• doesn't seem to have a future downside — when we remove the config, it doesn't break anything. If anything it might give us another opportunity to communicate that the feature is now stable.

2. Use option.default()

I spent some time fiddling with this. Functionally it does work. However, it doesn't execute and display the value with the --help option. E.g.:

$ yarn rw build --help
...
rw build [side..]

Build for production
...
      --esbuild    Use ESBuild for api side [experimental] [boolean] [default: (default)]
...

Yargs docs don't offer much help other than that "the function name will be used...". However, I tried changing the function name and it wouldn't build.

I'm assuming the priority is performance — avoid adding init time to Yargs — it was hard to determine the cost of not using the function. In several tests, the command execution time was identical. And we do already use something similar to default: getConfig()... to get Sides for rw test and language target for other commands.

I feel like the correct --help output value is helpful. Unless you have other ideas about how to finagle this, I'd prefer to use my original code.

?

[peterp]

@thedavidprice Ok, if that doesn't work then let's just add it by default. I need to make those functions lazy.