Only watch specified directory (--watch CLI param)

[ActivistChecklist]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the feature has not already been requested

🚀 Feature Proposal

Allow a directory (or list of directories) to be passed into the --watch param

Motivation

In my project, I have a small API subfolder. When I turn on --watch, it is monitoring my entire project root for changes, which leads to resets constantly.

Example

Right now the only solution is to do something like this:

fastify start --watch --ignore-watch '.git node_modules out .next content public scripts utils styles pages config compontents' --log-level info --pretty-logs --port ${API_PORT:-4321} api/server.js

I would rather do this:

fastify start --watch api --log-level info --pretty-logs --port ${API_PORT:-4321} api/server.js

[mcollina]

Thanks for reporting! Would you like to send a Pull Request to address this issue? Remember to add unit tests.

[jean-michelet]

Good idea @ActivistChecklist,

Maybe look at the ignore-watch related code to take inspiration and do it the other way.

[EmilianoBruni]

I've gone crazy with Watch and the problem is the code below that is crazy (and obviously undocumented)

I needed to watch only in "dist". But nothing work. And now I know why. Because fastify add dist by default. But if I ignore ".ts$", voilà 👎

Ok if I don't set anything but I think that if I set ignore-watch I know what folders I want to exclude.

From: https://github.com/fastify/fastify-cli/blob/590f350d1a586f68e78ecc72a8cc1b17ce1507a0/args.js#L7C1-L7C93

const DEFAULT_IGNORE = 'node_modules build dist .git bower_components logs .swp .nyc_output'
.....
let ignoreWatch = `${DEFAULT_IGNORE} ${ignoreWatchArg}`.trim()
  if (ignoreWatchArg.includes('.ts$')) {
    ignoreWatch = ignoreWatch.replace('dist', '')
  }