Add rule to exclude a path, like the inverse of `pick`

Feature request: In cases where there are lots of directories and files to include from a dependency module except one, it would be nice to be able to specify explicit paths to omit completely, rather than using pick to verbosely declare everything to include.

I would suggest either:

1. Add an omit or exclude keyword for use in rule definitions
2. Support exclusion rules as part of pick statements with bangs, e.g. pick: ! hey/neat/this/could/also/support/globbing/**

I think I prefer 2.

[olson-sean-k]

drop looks good to me!

A bit unrelated, but before bumping to 1.0, maybe we can review open issues and discuss?

[oconnor663]

Ugh, I hate that PyYAML silently drops duplicated fields. There’s a very hacky warning in place to try to detect cases where that’s happening though. Did it trigger for you when you duplicated the delete field?

As happy as I am to see someone using a multi-rule pipe, you’re right that you don’t need it in this case. What you want here is to give delete a YAML-formatted list of entries. So either this:

rule skip-default-wp-themes:
  delete:
    - wp-content/themes/twenty*
    - wp-content/plugins/hello.php

or this

rule skip-default-wp-themes:
  delete: ["wp-content/themes/twenty*", "wp-content/plugins/hello.php"]

I don’t think the quotes are strictly necessary in that second example, but YAML parsing starts to get really unpredictable as soon as * and other interesting syntax get involved.

I haven’t documented this yet, mostly because I felt like the README was getting too long, and I didn’t want to weigh it down with too many advanced use cases. I think what I should do now is split off an Advanced document, cram all this stuff in there, and just link to it from the main. We could move a ton of stuff under the fold like that.