commands/plugin: state file keeps track of the Vagrant version

plugins/commands/plugin/state_file.rb

@@ -9,16 +9,23 @@ module VagrantPlugins
         @path = path
 
         @data = {}
-        @data = JSON.parse(@path.read) if @path.exist?
+        if @path.exist?
-        @data["installed"] ||= []
+          @data = JSON.parse(@path.read)
+          upgrade_v0! if !@data["version"]
+        end
+
+        @data["version"] ||= "1"
+        @data["installed"] ||= {}
       end
 
       # Add a plugin that is installed to the state file.
       #
       # @param [String] name The name of the plugin
       def add_plugin(name)
-        if !@data["installed"].include?(name)
+        if !@data["installed"].has_key?(name)
-          @data["installed"] << name
+          @data["installed"][name] = {
+            "vagrant_version" => Vagrant::VERSION,
+          }
         end
 
         save!
@@ -43,15 +50,27 @@ module VagrantPlugins
 
       # This saves the state back into the state file.
       def save!
-        # Scrub some fields
-        @data["installed"].sort!
-        @data["installed"].uniq!
-
-        # Save
         @path.open("w+") do |f|
           f.write(JSON.dump(@data))
         end
       end
+
+      protected
+
+      # This upgrades the internal data representation from V0 (the initial
+      # version) to V1.
+      def upgrade_v0!
+        @data["version"] = "1"
+
+        new_installed = {}
+        (@data["installed"] || []).each do |plugin|
+          new_installed[plugin] = {}
+        end
+
+        @data["installed"] = new_installed
+
+        save!
+      end
     end
   end
 end

test/unit/plugins/commands/plugin/state_file_test.rb

@@ -18,6 +18,7 @@ describe VagrantPlugins::CommandPlugin::StateFile do
 
   subject { described_class.new(path) }
 
+  context "new usage" do
     it "should have no plugins without saving some" do
       expect(subject.installed_plugins).to be_empty
     end
@@ -26,7 +27,9 @@ describe VagrantPlugins::CommandPlugin::StateFile do
       subject.add_plugin("foo")
 
       instance = described_class.new(path)
-    expect(instance.installed_plugins).to eql(["foo"])
+      plugins = instance.installed_plugins
+      expect(plugins.length).to eql(1)
+      expect(plugins["foo"]).to eql({ "vagrant_version" => Vagrant::VERSION })
     end
 
     it "should remove plugins" do
@@ -42,6 +45,23 @@ describe VagrantPlugins::CommandPlugin::StateFile do
       subject.add_plugin("foo")
 
       instance = described_class.new(path)
-    expect(instance.installed_plugins).to eql(["foo"])
+      expect(instance.installed_plugins.keys).to eql(["foo"])
+    end
+  end
+
+  context "with an old-style file" do
+    before do
+      data = {
+        "installed" => ["foo"],
+      }
+
+      path.open("w+") do |f|
+        f.write(JSON.dump(data))
+      end
+    end
+
+    it "should have the right installed plugins" do
+      subject.installed_plugins.keys.should eql(["foo"])
+    end
   end
 end