From 0caa4c93a00362b3b36e340d2cc541e6f39f7aec Mon Sep 17 00:00:00 2001
From: Patrick Hogan <pbhogan@gmail.com>
Date: Wed, 22 May 2024 14:45:36 -0500
Subject: [PATCH] Add an option (--filter) to allow filtering change events to
 modified, added and/or removed

---
 lib/rerun/options.rb |  5 +++++
 lib/rerun/watcher.rb | 23 ++++++++++++++++++++---
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/lib/rerun/options.rb b/lib/rerun/options.rb
index 9707603..639f58b 100644
--- a/lib/rerun/options.rb
+++ b/lib/rerun/options.rb
@@ -29,6 +29,7 @@ class Options
       :signal => (windows? ? "TERM,KILL" : "TERM,INT,KILL"),
       :verbose => false,
       :wait => 2,
+      :filter => [:modified, :added, :removed]
     }
 
     def self.parse args: ARGV, config_file: nil
@@ -68,6 +69,10 @@ def self.parse args: ARGV, config_file: nil
           options[:ignore] += [pattern]
         end
 
+        o.on("-f changes", "--filter", "changes to respond to, default = #{DEFAULTS[:filter].join(",")}") do |value|
+          options[:filter] = value.strip.split(/\s*,\s*/).reject(&:empty?).map(&:to_sym)
+        end
+
         o.on("--[no-]ignore-dotfiles", "by default, file globs do not match files that begin with a dot. Setting --no-ignore-dotfiles allows you to monitor a relevant file like .env, but you may also have to explicitly --ignore more dotfiles and dotdirs.") do |value|
           options[:ignore_dotfiles] = value
         end
diff --git a/lib/rerun/watcher.rb b/lib/rerun/watcher.rb
index f6eb83f..b09e5b5 100644
--- a/lib/rerun/watcher.rb
+++ b/lib/rerun/watcher.rb
@@ -32,6 +32,7 @@ def initialize(options = {}, &client_callback)
       options = {
           :directory => ".",
           :pattern => "**/*",
+          :filter => [:modified, :added, :removed],
           :priority => 0,
           :ignore_dotfiles => true,
       }.merge(options)
@@ -39,6 +40,7 @@ def initialize(options = {}, &client_callback)
       @pattern = options[:pattern]
       @directories = options[:directory]
       @directories = sanitize_dirs(@directories)
+      @filter = options[:filter]
       @priority = options[:priority]
       @force_polling = options[:force_polling]
       @ignore = [options[:ignore]].flatten.compact
@@ -57,6 +59,21 @@ def sanitize_dirs(dirs)
       end
     end
 
+    def filter_changes(modified, added, removed)
+      changes = { modified: [], added: [], removed: [] }
+      @filter.each do |change|
+        case change
+        when :modified
+          changes[:modified] = modified
+        when :added
+          changes[:added] = added
+        when :removed
+          changes[:removed] = removed
+        end
+      end
+      changes
+    end
+
     def start
       if @thread then
         raise RuntimeError, "already started"
@@ -64,9 +81,9 @@ def start
 
       @thread = Thread.new do
         @listener = Listen.to(*@directories, only: watching, ignore: ignoring, wait_for_delay: 1, force_polling: @force_polling) do |modified, added, removed|
-          count = modified.size + added.size + removed.size
-          if count > 0
-            @client_callback.call(:modified => modified, :added => added, :removed => removed)
+          changes = filter_changes(modified, added, removed)
+          if changes.each_value.map(&:size).sum > 0
+            @client_callback.call(**changes)
           end
         end
         @listener.start