1 files changed, 140 insertions, 0 deletions
diff --git a/lib/gitlab/quick_actions/dsl.rb b/lib/gitlab/quick_actions/dsl.rb
new file mode 100644
index 00000000000..a4a97236ffc
--- /dev/null
+++ b/lib/gitlab/quick_actions/dsl.rb
@@ -0,0 +1,140 @@
+module Gitlab
+  module QuickActions
+    module Dsl
+      extend ActiveSupport::Concern
+
+      included do
+        cattr_accessor :command_definitions, instance_accessor: false do
+          []
+        end
+
+        cattr_accessor :command_definitions_by_name, instance_accessor: false do
+          {}
+        end
+      end
+
+      class_methods do
+        # Allows to give a description to the next quick action.
+        # This description is shown in the autocomplete menu.
+        # It accepts a block that will be evaluated with the context given to
+        # `CommandDefintion#to_h`.
+        #
+        # Example:
+        #
+        #   desc do
+        #     "This is a dynamic description for #{noteable.to_ability_name}"
+        #   end
+        #   command :command_key do |arguments|
+        #     # Awesome code block
+        #   end
+        def desc(text = '', &block)
+          @description = block_given? ? block : text
+        end
+
+        # Allows to define params for the next quick action.
+        # These params are shown in the autocomplete menu.
+        #
+        # Example:
+        #
+        #   params "~label ~label2"
+        #   command :command_key do |arguments|
+        #     # Awesome code block
+        #   end
+        def params(*params, &block)
+          @params = block_given? ? block : params
+        end
+
+        # Allows to give an explanation of what the command will do when
+        # executed. This explanation is shown when rendering the Markdown
+        # preview.
+        #
+        # Example:
+        #
+        #   explanation do |arguments|
+        #     "Adds label(s) #{arguments.join(' ')}"
+        #   end
+        #   command :command_key do |arguments|
+        #     # Awesome code block
+        #   end
+        def explanation(text = '', &block)
+          @explanation = block_given? ? block : text
+        end
+
+        # Allows to define conditions that must be met in order for the command
+        # to be returned by `.command_names` & `.command_definitions`.
+        # It accepts a block that will be evaluated with the context given to
+        # `CommandDefintion#to_h`.
+        #
+        # Example:
+        #
+        #   condition do
+        #     project.public?
+        #   end
+        #   command :command_key do |arguments|
+        #     # Awesome code block
+        #   end
+        def condition(&block)
+          @condition_block = block
+        end
+
+        # Allows to perform initial parsing of parameters. The result is passed
+        # both to `command` and `explanation` blocks, instead of the raw
+        # parameters.
+        # It accepts a block that will be evaluated with the context given to
+        # `CommandDefintion#to_h`.
+        #
+        # Example:
+        #
+        #   parse_params do |raw|
+        #     raw.strip
+        #   end
+        #   command :command_key do |parsed|
+        #     # Awesome code block
+        #   end
+        def parse_params(&block)
+          @parse_params_block = block
+        end
+
+        # Registers a new command which is recognizeable from body of email or
+        # comment.
+        # It accepts aliases and takes a block.
+        #
+        # Example:
+        #
+        #   command :my_command, :alias_for_my_command do |arguments|
+        #     # Awesome code block
+        #   end
+        def command(*command_names, &block)
+          name, *aliases = command_names
+
+          definition = CommandDefinition.new(
+            name,
+            aliases: aliases,
+            description: @description,
+            explanation: @explanation,
+            params: @params,
+            condition_block: @condition_block,
+            parse_params_block: @parse_params_block,
+            action_block: block
+          )
+
+          self.command_definitions << definition
+
+          definition.all_names.each do |name|
+            self.command_definitions_by_name[name] = definition
+          end
+
+          @description = nil
+          @explanation = nil
+          @params = nil
+          @condition_block = nil
+          @parse_params_block = nil
+        end
+
+        def definition_by_name(name)
+          command_definitions_by_name[name.to_sym]
+        end
+      end
+    end
+  end
+end