Rewatch - The --dev flag should be applied by default

[DZakh]

With rewatch, it now requires passing the --dev flag to make the "type": "dev" files be compiled. This means if you are using development files in your project, you need to add the --dev flag for every command you are running. I strongly believe that this behavior should be opt-out instead of opt-in.

[rolandpeelen]

Historic context:

• We initially did not build dev-deps at all, because we did not distinguish between local packages / dependant packages
• We then introduced this flag to force the compilation of development dependencies: rescript-lang/rewatch@b452b3e
• Then that distinguishment came: Only get dev_deps from local packages #7646

Since we now have that, we can compile dev deps by default for local packages. So yeah. You could just update the default in clap in main.rs to true.

[DZakh]

I think the packages setup is good. I'm talking about the project sources:

"sources": [
    {
      "dir": "src",
      "public": ["S", "JSONSchema"]
    },
    {
      "dir": "tests",
      "type": "dev"
    },
    {
      "dir": "scripts",
      "type": "dev",
      "subdirs": true
    }
  ],

Previously, all of them were compiled. Now it requires the --dev flag

[nojaf]

The --dev flag currently controls:

• if dev-dependencies of local packages should be read and later compiled. source
• if local "type": "dev" sources should be compiled. source

Given the original context, having a --release flag might make more sense.
This would do the reverse.

[rolandpeelen]

@DZakh - Yeah, that is exactly what the --dev flag does.

The problem was in the beginning that when you had something in node_modules that included some sources with type: dev but subsequently didn't include the actual folder / file, it would fail to compile.

But now that we distinguish between local dev dependencies and non-local (ie from node_modules), we can just compile local ones. So setting --dev to true as a default for local modules only, would mimic behaviour of bsc.

We could add a 'release' flag that ignores them outright (ie - the opposite of what it does now). It would just be the same a --dev=false but with a different name :).

For backwards compabitility I would keep --dev for now, but default it to true (it won't bother anyone who has not had to deal with it, and the ones who have have probably explicitly set it to true). Then we can add a --release flag which just sets the variable --dev maps to to false, and have that take precedence. Then we can deprecate the --dev flag in some next release

[rolandpeelen]

@nojaf - In the original context, we couldn't discern between local / non-local. So if we had a release flag, defaulting to building all the dev files, we got compile errors all the time - notably, rescript-jest. It included the tests folder, but that wasn't distributed via npm.