Handle ranges of peer dependencies

[lancefisher]

Problem

Running

install-peerdeps eslint-config-airbnb --dev --yarn

mentions that it will run:

install-peerdeps v1.1.2
Installing peerdeps for eslint-config-airbnb@14.1.0.
yarn add eslint-config-airbnb eslint@^3.15.0 eslint-plugin-jsx-a11y@^3.0.2 || ^4.0.0 eslint-plugin-import@^2.2.0 eslint-plugin-react@^6.9.0 --dev

eslint-plugin-jsx-a11y@^3.0.2 || ^4.0.0 is problematic here, and the following error occurs:

yarn add v0.19.1
[1/4] 🔍  Resolving packages...
error Couldn't find package "^4.0.0" on the "npm" registry.
info Visit https://yarnpkg.com/en/docs/cli/add for documentation about this command.
ERR The install process exited with error code 1.

Solution

If a peer dependency is a range like ^3.0.2 || ^4.0.0, just install the last mentioned comparator. i.e. ^4.0.0.

This also works for ranges specified as >=1.2.7 <1.3.0.

[nathanhleung]

Thanks for the pull! It looks good to me, but for future pulls I want to set up CI and tests, so just hang tight while I put that together.

[nathanhleung]

I added another commit to the pull to get the linting to pass and made one variable a little more clear — thanks again for your contribution!

[lancefisher]

@nathanhleung Great! Thanks for this tool!