Use prepack and postpack rather than prepublishOnly and postpublish

[oliverlangan]

As an app or addon publisher, I want my type definitions created in prepack so that I can use a non-standard publishing mechanism.

According to the npm scripts documentation, prepublishOnly only runs on npm publish (and presumably yarn publish), but our CI/publish environment uses neither.

I believe it would be more flexible to use prepack instead of prepublishOnly; and in the interest of making it symmetric, I suggest we also use postpack instead of postpublish.

[chriskrycho]

Thanks for filing this—we'll definitely consider it!

[chriskrycho]

Cc. @chancancode @dfreeman @jamescdavis @hjdivad

[dfreeman]

IIRC we originally went with prepublishOnly/postpublish because Yarn didn't trigger prepack and postpack during publish, so that was our only practical lifecycle hook that would work consistently between Yarn and npm.

While Yarn 1 still plays a bit fast and loose compared to Yarn 2 and npm in terms of when it executes lifecycle scripts, it does look like prepack and postpack trigger correctly during publish in recent Yarn 1.x releases, so this change seems reasonable to me.

For both npm and Yarn 2, I believe this would also make installation from git remotes work properly without requiring any special effort from addon authors, but that's one area where Yarn 1 is still divergent from the other managers in the ecosystem.

[hjdivad]

FWIW we use prepack / postpack at LinkedIn to support custom publishing. It sounds very similar to what @oliverlangan's setup is.