I had previously introduced a lot of updates and fixes to npm registry
based completions for `yarn` but hadn't ported them to `npm` as well
(although they can be dropped in as-is). This patch shares the code
between the two, which resides in an explicitly sourced multi-function
fish script.
The informational message is only shown the first time an attempt at
completing `yarn add` is made per session. This should vastly improve
the discoverability of this feature as regular yarn/npm users would
never have `all-the-package-names` installed normally.
Fixes some potentially unsafe uses of direct substitution into regex
expressions and also switches some completions to regex-based now that
there is a safe way of using it.
Don't attempt to complete against package names if the user is trying to
enter a switch to speed things up.
Also work around #5267 by not wrapping unfiltered `all-the-package-name`
calls in a function.
bower was calling `__fish_should_complete_args`, the old name for
`__fish_should_complete_switches.`
yarn was parsing bower.json instead of package.json.
Now parses package.json and uses results to provide a list of possible
completions to `yarn remove`. There may be other subcommands that could
benefit from this.
Could have parsed yarn output, but yarn is slow and packages.json format
is generally standard since it's machine-generated json.
