Added files ignored by guard plugins

[nilbus]

@rymai and @thibaudgg decided in #495 (comment) and #495 (comment) to drop support in several plugins for running on created/added files, in favor of avoiding redundant runs on save in editors like vim and Sublime configured for atomic save (e.g. guard/guard-minitest#98). This is usually a great tradeoff since a new file can generally be saved again to trigger a run.

Unfortunately this is fatal for users of the mutagen file sync tool. Our team uses mutagen to efficiently bi-directionally sync changes between our OSX Docker hosts and Docker containers for development where guard runs. In order to sync files atomically, when a file is modified on the host, mutagen moves a new copy of the file into place. The result is that listen detects every modification as a :moved_to or :added event, and therefore many guard plugins never run on changes synced by mutagen.

I'm posting this issue on the guard project because many guard plugins are affected.

I have confirmed that aliasing plugins' run_on_modification as run_on_additions (and removing any existing no-op run_on_additions method) resolves the problem.

I want to make sure that we don't re-introduce the multiple runs per save issue previously reported. Has anything changed since #495 was filed in 2013 that would prevent multiple runs for a single save in editors configured for backup/atomic save, or would such aliases likely reintroduce the problem?

If I can determine how to effectively support allowing added files to trigger runs without the multiple runs problem for affected editors, then is this a change that you would be willing to accept? The project has been a little quiet, so I'd like to hear support from a maintainer before I sink time into this.

Thanks!

[WoolenWang]

When we copy files, this will ignore the added file, which is not expect (when we have a task with sync files to other server) .

so pls let us config to designed it should ignore or not

[adamaig]

I'm running into a similar issue due to the docker4mac/osxfs usage + my vim settings This is relatively easy to work around by monkey-patching the Guard::RSpec plugin in the guard file.

guard :rspec, cmd: "bundle exec rspec" do
  require "guard/rspec"
  module ::Guard
    class RSpec < Plugin
      def run_on_changes(paths)
        run_on_modifications(paths)
     end
  end

  # watch rules ...

end

It would be a nice extension to make it more configurable based on events that guard receives so that a user can readily configure which events trigger plugin methods, rather than forcing users to modify editors (and other software) in order to work with this software.

[rymai]

It would be a nice extension to make it more configurable based on events that guard receives so that a user can readily configure which events trigger plugin methods, rather than forcing users to modify editors (and other software) in order to work with this software.

I think it could be a good idea to introduce a new plugin option, e.g. consider_additions_as_modifications: true and consider_removals_as_modifications: true to force a plugin to process additions and removals even if its default behavior doesn't.