commands_map.rb in chef-dk-3.0.36

- old
+ new
@@ -1,113 +1,113 @@
-#
-# Copyright:: Copyright (c) 2016 Chef Software Inc.
-# License:: Apache License, Version 2.0
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-#
-
-module ChefDK
-
-  # CommandsMap maintains a mapping of subcommand names to the files where
-  # those commands are defined and the classes that implement the commands.
-  #
-  # In ruby it's more typical to handle this sort of thing using conventions
-  # and metaprogramming. We've implemented this approach in the past and
-  # decided against it here:
-  # 1. Performance. As the CLI suite grows, you have to load more and more
-  # code, including dependencies that are installed by rubygems, etc. This gets
-  # slow, and CLI apps need to be fast.
-  # 2. You can workaround the above by having a convention mapping filename to
-  # command name, but then you have to do a lot of work to list all of the
-  # commands, which is actually a common thing to do.
-  # 3. Other ways to mitigate the performance issue (loading deps lazily) have
-  # their own complications and tradeoffs and don't fully solve the problem.
-  # 4. It's not actually that much work to maintain the mapping.
-  #
-  # ## Adding new commands globally:
-  #
-  # A "singleton-ish" instance of this class is stored as ChefDK.commands_map.
-  # You can configure a multiple commands at once in a block using
-  # ChefDK.commands, like so:
-  #
-  #   ChefDK.commands do |c|
-  #     # assigns `chef my-command` to the class ChefDK::Command::MyCommand.
-  #     # The "require path" is inferred to be "chef-dk/command/my_command"
-  #     c.builtin("my-command", :MyCommand)
-  #
-  #     # Set the require path explicitly:
-  #     c.builtin("weird-command", :WeirdoClass, require_path: "chef-dk/command/this_is_cray")
-  #
-  #     # You can add a description that will show up in `chef -h` output (recommended):
-  #     c.builtin("documented-cmd", :DocumentedCmd, desc: "A short description")
-  #   end
-  #
-  class CommandsMap
-    NULL_ARG = Object.new
-
-    CommandSpec = Struct.new(:name, :constant_name, :require_path, :description, :hidden)
-
-    class CommandSpec
-
-      def instantiate
-        require require_path
-        command_class = ChefDK::Command.const_get(constant_name)
-        command_class.new
-      end
-
-    end
-
-    attr_reader :command_specs
-
-    def initialize
-      @command_specs = {}
-    end
-
-    def builtin(name, constant_name, require_path: NULL_ARG, desc: "", hidden: false)
-      if null?(require_path)
-        snake_case_path = name.tr("-", "_")
-        require_path = "chef-dk/command/#{snake_case_path}"
-      end
-      command_specs[name] = CommandSpec.new(name, constant_name, require_path, desc, hidden)
-    end
-
-    def instantiate(name)
-      spec_for(name).instantiate
-    end
-
-    def have_command?(name)
-      command_specs.key?(name)
-    end
-
-    def command_names
-      command_specs.keys
-    end
-
-    def spec_for(name)
-      command_specs[name]
-    end
-
-    private
-
-    def null?(argument)
-      argument.equal?(NULL_ARG)
-    end
-  end
-
-  def self.commands_map
-    @commands_map ||= CommandsMap.new
-  end
-
-  def self.commands
-    yield commands_map
-  end
-end
+#
+# Copyright:: Copyright (c) 2016 Chef Software Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+module ChefDK
+
+  # CommandsMap maintains a mapping of subcommand names to the files where
+  # those commands are defined and the classes that implement the commands.
+  #
+  # In ruby it's more typical to handle this sort of thing using conventions
+  # and metaprogramming. We've implemented this approach in the past and
+  # decided against it here:
+  # 1. Performance. As the CLI suite grows, you have to load more and more
+  # code, including dependencies that are installed by rubygems, etc. This gets
+  # slow, and CLI apps need to be fast.
+  # 2. You can workaround the above by having a convention mapping filename to
+  # command name, but then you have to do a lot of work to list all of the
+  # commands, which is actually a common thing to do.
+  # 3. Other ways to mitigate the performance issue (loading deps lazily) have
+  # their own complications and tradeoffs and don't fully solve the problem.
+  # 4. It's not actually that much work to maintain the mapping.
+  #
+  # ## Adding new commands globally:
+  #
+  # A "singleton-ish" instance of this class is stored as ChefDK.commands_map.
+  # You can configure a multiple commands at once in a block using
+  # ChefDK.commands, like so:
+  #
+  #   ChefDK.commands do |c|
+  #     # assigns `chef my-command` to the class ChefDK::Command::MyCommand.
+  #     # The "require path" is inferred to be "chef-dk/command/my_command"
+  #     c.builtin("my-command", :MyCommand)
+  #
+  #     # Set the require path explicitly:
+  #     c.builtin("weird-command", :WeirdoClass, require_path: "chef-dk/command/this_is_cray")
+  #
+  #     # You can add a description that will show up in `chef -h` output (recommended):
+  #     c.builtin("documented-cmd", :DocumentedCmd, desc: "A short description")
+  #   end
+  #
+  class CommandsMap
+    NULL_ARG = Object.new
+
+    CommandSpec = Struct.new(:name, :constant_name, :require_path, :description, :hidden)
+
+    class CommandSpec
+
+      def instantiate
+        require require_path
+        command_class = ChefDK::Command.const_get(constant_name)
+        command_class.new
+      end
+
+    end
+
+    attr_reader :command_specs
+
+    def initialize
+      @command_specs = {}
+    end
+
+    def builtin(name, constant_name, require_path: NULL_ARG, desc: "", hidden: false)
+      if null?(require_path)
+        snake_case_path = name.tr("-", "_")
+        require_path = "chef-dk/command/#{snake_case_path}"
+      end
+      command_specs[name] = CommandSpec.new(name, constant_name, require_path, desc, hidden)
+    end
+
+    def instantiate(name)
+      spec_for(name).instantiate
+    end
+
+    def have_command?(name)
+      command_specs.key?(name)
+    end
+
+    def command_names
+      command_specs.keys
+    end
+
+    def spec_for(name)
+      command_specs[name]
+    end
+
+    private
+
+    def null?(argument)
+      argument.equal?(NULL_ARG)
+    end
+  end
+
+  def self.commands_map
+    @commands_map ||= CommandsMap.new
+  end
+
+  def self.commands
+    yield commands_map
+  end
+end