Fix source watcher configuration (#1999)

* Fix source watcher configuration

* Keep old Sources#initialize signature

* Poll source on path change

middleman-core/lib/middleman-core/application.rb

@@ -203,6 +203,7 @@ module Middleman
     define_setting :watcher_disable, false, 'If the Listen watcher should not run'
     define_setting :watcher_force_polling, false, 'If the Listen watcher should run in polling mode'
     define_setting :watcher_latency, nil, 'The Listen watcher latency'
+    define_setting :watcher_wait_for_delay, 0.5, 'The Listen watcher delay between calls when changes exist'
 
     # Delegate convenience methods off to their implementations
     def_delegator :"::Middleman::Logger", :singleton, :logger

middleman-core/lib/middleman-core/core_extensions/file_watcher.rb

@@ -28,10 +28,7 @@ module Middleman
         super
 
         # Setup source collection.
-        @sources = ::Middleman::Sources.new(app,
-                                            disable_watcher: app.config[:watcher_disable],
-                                            force_polling: app.config[:watcher_force_polling],
-                                            latency: app.config[:watcher_latency])
+        @sources = ::Middleman::Sources.new(app)
 
         # Add default ignores.
         IGNORES.each do |key, value|
@@ -55,6 +52,13 @@ module Middleman
       # @return [void]
       Contract Any
       def after_configuration
+        @watcher.update_config(
+          disable_watcher: app.config[:watcher_disable],
+          force_polling: app.config[:watcher_force_polling],
+          latency: app.config[:watcher_latency],
+          wait_for_delay: app.config[:watcher_wait_for_delay]
+        )
+
         if @original_source_dir != app.config[:source]
           @watcher.update_path(app.config[:source])
         end

middleman-core/lib/middleman-core/sources.rb

@@ -56,15 +56,13 @@ module Middleman
     # @param [Hash] options Global options.
     # @param [Array] watchers Default watchers.
     Contract IsA['Middleman::Application'], Maybe[Hash], Maybe[Array] => Any
-    def initialize(app, options={}, watchers=[])
+    def initialize(app, _options={}, watchers=[])
       @app = app
       @watchers = watchers
       @sorted_watchers = @watchers.dup.freeze
 
       ::Middleman::Sources.file_cache = {}
 
-      @options = options
-
       # Set of procs wanting to be notified of changes
       @on_change_callbacks = ::Hamster::Vector.empty
 
@@ -172,7 +170,7 @@ module Middleman
     # @return [Middleman::Sources]
     Contract Symbol => ::Middleman::Sources
     def by_type(type)
-      self.class.new @app, @options, watchers.select { |d| d.type == type }
+      self.class.new @app, nil, watchers.select { |d| d.type == type }
     end
 
     # Get all files for this collection of watchers.

middleman-core/lib/middleman-core/sources/source_watcher.rb

@@ -75,9 +75,10 @@ module Middleman
       @ignored = options.fetch(:ignored, proc { false })
       @only = Array(options.fetch(:only, []))
 
-      @disable_watcher = app.build? || @parent.options.fetch(:disable_watcher, false)
-      @force_polling = @parent.options.fetch(:force_polling, false)
-      @latency = @parent.options.fetch(:latency, nil)
+      @disable_watcher = app.build?
+      @force_polling = false
+      @latency = nil
+      @wait_for_delay = nil
 
       @listener = nil
 
@@ -95,13 +96,20 @@ module Middleman
     def update_path(directory)
       @directory = Pathname(File.expand_path(directory, app.root))
 
-      stop_listener! if @listener
-
-      update([], @files.values.map { |source_file| source_file[:full_path] })
+      without_listener_running do
+        update([], @files.values.map { |source_file| source_file[:full_path] })
+      end
 
       poll_once!
+    end
 
-      listen! unless @disable_watcher
+    def update_config(options={})
+      without_listener_running do
+        @disable_watcher = options.fetch(:disable_watcher, false)
+        @force_polling = options.fetch(:force_polling, false)
+        @latency = options.fetch(:latency, nil)
+        @wait_for_delay = options.fetch(:wait_for_delay, nil)
+      end
     end
 
     # Stop watching.
@@ -160,10 +168,10 @@ module Middleman
 
       config = {
         force_polling: @force_polling,
-        wait_for_delay: 0.5
       }
 
-      config[:latency] = @latency.to_i if @latency
+      config[:wait_for_delay] = @wait_for_delay.try(:to_f) || 0.5
+      config[:latency] = @latency.to_f if @latency
 
       @listener = ::Listen.to(@directory.to_s, config, &method(:on_listener_change))
 
@@ -343,5 +351,20 @@ module Middleman
         @only.any? { |reg| file[:relative_path].to_s =~ reg }
       end
     end
+
+    private
+
+    def without_listener_running
+      listener_running = @listener && @listener.processing?
+
+      stop_listener! if listener_running
+
+      yield
+
+      if listener_running
+        poll_once!
+        listen!
+      end
+    end
   end
 end