Use a pushes registry instead of data hash

lib/vagrant/plugin/v2/components.rb

@@ -54,6 +54,11 @@ module Vagrant
         # @return [Hash<Symbol, Registry>]
         attr_reader :provider_capabilities
 
+        # This contains all the push implementations by name.
+        #
+        # @return [Registry<Symbol, Array<Class, Hash>>]
+        attr_reader :pushes
+
         # This contains all the synced folder implementations by name.
         #
         # @return [Registry<Symbol, Array<Class, Integer>>]
@@ -71,6 +76,7 @@ module Vagrant
           @host_capabilities = Hash.new { |h, k| h[k] = Registry.new }
           @providers = Registry.new
           @provider_capabilities = Hash.new { |h, k| h[k] = Registry.new }
+          @pushes = Registry.new
           @synced_folders = Registry.new
         end
       end

lib/vagrant/plugin/v2/plugin.rb

@@ -224,16 +224,13 @@ module Vagrant
         # Registers additional pushes to be available.
         #
         # @param [String] name Name of the push.
+        # @param [Hash] options List of options for the push.
         def self.push(name=UNSET_VALUE, options=nil, &block)
-          data[:pushes] ||= Registry.new
-
-          # Register a new pusher class only if a name was given
-          if name != UNSET_VALUE
-            data[:pushes].register(name.to_sym) { [block.call, options] }
+          components.pushes.register(name.to_sym) do
+            [block.call, options]
           end
 
-          # Return the registry
-          data[:pushes]
+          nil
         end
 
         # Registers additional synced folder implementations.

test/unit/vagrant/plugin/v2/plugin_test.rb

@@ -322,6 +322,41 @@ describe Vagrant::Plugin::V2::Plugin do
     end
   end
 
+  describe "pushes" do
+    it "should register implementations" do
+      plugin = Class.new(described_class) do
+        push("foo") { "bar" }
+      end
+
+      expect(plugin.components.pushes[:foo]).to eq(["bar", nil])
+    end
+
+    it "should be able to specify priorities" do
+      plugin = Class.new(described_class) do
+        push("foo", bar: 1) { "bar" }
+      end
+
+      expect(plugin.components.pushes[:foo]).to eq(["bar", bar: 1])
+    end
+
+    it "should lazily register implementations" do
+      # Below would raise an error if the value of the config class was
+      # evaluated immediately. By asserting that this does not raise an
+      # error, we verify that the value is actually lazily loaded
+      plugin = nil
+      expect {
+        plugin = Class.new(described_class) do
+          push("foo") { raise StandardError, "FAIL!" }
+        end
+      }.to_not raise_error
+
+      # Now verify when we actually get the configuration key that
+      # a proper error is raised.
+      expect {
+        plugin.components.pushes[:foo]
+      }.to raise_error(StandardError)
+    end
+  end
   describe "synced folders" do
     it "should register implementations" do
       plugin = Class.new(described_class) do