Change to automatically spin top level spinner under multi spinner

lib/tty/spinner/multi.rb

@@ -68,7 +68,8 @@ def initialize(*args)
         @callbacks = {
           success: [],
           error:   [],
-          done:    []
+          done:    [],
+          spin:    []
         }
       end
 
@@ -122,7 +123,6 @@ def top_spinner
       def auto_spin
         raise "No top level spinner" if @top_spinner.nil?
 
-        @top_spinner.auto_spin
         jobs = []
         @spinners.each do |spinner|
           if spinner.job?
@@ -139,7 +139,9 @@ def auto_spin
       def spin
         raise "No top level spinner" if @top_spinner.nil?
 
-        @top_spinner.spin
+        synchronize do
+          throttle { @top_spinner.spin }
+        end
       end
 
       # Pause all spinners
@@ -239,14 +241,30 @@ def error
       def on(key, &callback)
         unless @callbacks.key?(key)
           raise ArgumentError, "The event #{key} does not exist. "\
-                               " Use :success, :error, or :done instead"
+                               ' Use :spin, :success, :error, or :done instead'
         end
         @callbacks[key] << callback
         self
       end
 
       private
 
+      # Check if this spinner should revolve to keep constant speed
+      # matching top spinner interval
+      #
+      # @api private
+      def throttle
+        sleep_time = 1.0 / @top_spinner.interval
+        if @last_spin_at && Time.now - @last_spin_at < sleep_time
+          return
+        end
+        yield if block_given?
+        @last_spin_at = Time.now
+      end
+
+      # Fire an event
+      #
+      # @api private
       def emit(key, *args)
         @callbacks[key].each do |block|
           block.call(*args)
@@ -260,11 +278,22 @@ def emit(key, *args)
       #
       # @api private
       def observe(spinner)
-        spinner.on(:success, &success_handler)
+        spinner.on(:spin, &spin_handler)
+               .on(:success, &success_handler)
                .on(:error, &error_handler)
                .on(:done, &done_handler)
       end
 
+      # Handle spin event
+      #
+      # @api private
+      def spin_handler
+        proc do
+          spin if @top_spinner
+          emit(:spin)
+        end
+      end
+
       # Handle the success state
       #
       # @api private
@@ -295,7 +324,7 @@ def error_handler
       def done_handler
         proc do
           if done?
-            @top_spinner.stop if @top_spinner
+            @top_spinner.stop if @top_spinner && !error? && !success?
             emit(:done)
           end
         end

spec/unit/multi/auto_spin_spec.rb

@@ -3,13 +3,13 @@
 RSpec.describe TTY::Spinner::Multi, '#auto_spin' do
   let(:output) { StringIO.new('', 'w+') }
 
-  it "auto spins top level spinner" do
+  it "doesn't auto spin top level spinner" do
     spinners = TTY::Spinner::Multi.new("Top level spinner", output: output)
-    allow_any_instance_of(TTY::Spinner).to receive(:auto_spin)
+    allow(spinners.top_spinner).to receive(:auto_spin)
 
     spinners.auto_spin
 
-    expect(spinners.top_spinner).to have_received(:auto_spin).once
+    expect(spinners.top_spinner).to_not have_received(:auto_spin)
   end
 
   it "raises an exception when called without a top spinner" do