Rewrite internals for v2 release

[mcous]

Overview

Work in progress!

This PR is a large-scale rewrite of the module, primarily concerned with fixing all outstanding (known) bugs, and grabbing a few easy features:

• Action modifies user's npmrc #15
• Checking for npm package existence should ignore tag and check against all versions #35
• If tag isn't specified, fall back to publishConfig #36
• Specify ignore-scripts when publishing #47
• working-directory not respected #51
• Configure publish directory #59

It will also lay the groundwork for #81, which can be tackled in its own PR.

Details

The core of this PR is a ground-up rewrite of how this module interacts with npm.

Previously, this action would read and then overwrite npm's user config (aka ~/.npmrc). This is a harmful thing to do! It interferes with configuration written by actions/setup-node, and if you happen to use the CLI version of the package, it would overwrite your own settings. See #15 for more details.

This PR changes the logic to write (and delete when we're done) an isolated .npmrc file in temporary storage, specific to this package. The action will no longer interfere with other tools, and other tools won't be able to interfere with this action.

Since the npm interaction code was being rewritten, it was easy to layer in some additional changes:

• Use the CLI's <package_spec> argument instead of changing the working directory
• Always pass --ignore-scripts to the CLI

On top of how the module calls npm, this PR also takes a top-down TDD approach to all internal interfaces and functions. A lot of the other fixes and changes fell out of that work, including:

• Rewrite manifest reading to also check publishConfig
• Move release version checking to its own submodule with better test coverage
  • e.g. check against all published versions, not just `dist-tags
• Replace check-version and greater-version-only options with a single strategy option that can be set to upgrade (default) or any
  • strategy: upgrade -> check-version: true, greater-version-only: true
  • strategy: any -> check-version: true, greater-version-only: false
  • Removed check-version: false, because you shouldn't be using this action if you don't want to check against published versions; you can just use npm