A fastlane action to create a new merge request on GitLab

create_merge_request.rb

module Fastlane
  module Actions
    module SharedValues
      CREATE_MERGE_REQUEST_WEB_URL = :CREATE_MERGE_REQUEST_WEB_URL
    end

    class CreateMergeRequestAction < Action
      def self.run(params)
        require 'excon'

        target_project_id = params[:target_project_id] ? params[:target_project_id] : params[:project_id]

        UI.message("Creating new merge request from #{params[:source]} of project #{params[:project_id]} to branch #{params[:target]} of project #{target_project_id}")

        # Build HTTP request
        url = "#{params[:api_url]}/projects/#{params[:project_id]}/merge_requests"

        headers = {
          'User-Agent' => 'fastlane-create_merge_request',
          'Content-Type' => 'application/json',
        }
        headers['PRIVATE-TOKEN'] = "#{params[:api_token]}" if params[:api_token]

        data = {
          'title' => params[:title],
          'source_branch' => params[:source],
          'target_branch' => params[:target],
        }
        data['description'] = params[:body] if params[:body]
        data['target_project_id'] = target_project_id

        # Post it
        response = Excon.post(url, headers: headers, body: data.to_json)

        if response[:status] == 201
          body = JSON.parse(response.body)
          id = body['iid']
          web_url = body['web_url']
          Actions.lane_context[SharedValues::CREATE_MERGE_REQUEST_WEB_URL] = web_url

          UI.success("Successfully created pull request ##{id}. You can see it at '#{web_url}'")
        elsif response[:status] != 200
          UI.error("GitLab responded with #{response[:status]}: #{response[:body]}")
        end
      end

      #####################################################
      # @!group Documentation
      #####################################################

      def self.description
        "Create a new merge request on GitLab"
      end

      def self.available_options
        [
          FastlaneCore::ConfigItem.new(key: :api_token,
                                       env_name: "GITLAB_MERGE_REQUEST_API_TOKEN",
                                       description: "Personal API Access Token for GitLab",
                                       sensitive: true,
                                       default_value: ENV["GITLAB_API_TOKEN"],
                                       is_string: true,
                                       optional: false),
          FastlaneCore::ConfigItem.new(key: :project_id,
                                       env_name: "GITLAB_MERGE_REQUEST_PROJECT_ID",
                                       description: "The id of the project",
                                       is_string: true,
                                       optional: false),
          FastlaneCore::ConfigItem.new(key: :target_project_id,
                                       env_name: "GITLAB_MERGE_REQUEST_PROJECT_TARGET_PROJECT_ID",
                                       description: "The id of the project you want to submit the merge request to",
                                       is_string: true,
                                       optional: true),
          FastlaneCore::ConfigItem.new(key: :title,
                                       env_name: "GITLAB_MERGE_REQUEST_TITLE",
                                       description: "The title of the merge request",
                                       is_string: true,
                                       optional: false),
          FastlaneCore::ConfigItem.new(key: :body,
                                       env_name: "GITLAB_MERGE_REQUEST_BODY",
                                       description: "The contents of the pull request",
                                       is_string: true,
                                       optional: true),
          FastlaneCore::ConfigItem.new(key: :source,
                                       env_name: "GITLAB_MERGE_REQUEST_SOURCE_BRANCH",
                                       description: "The name of the branch where your changes are implemented (defaults to the current branch name)",
                                       is_string: true,
                                       default_value: Actions.git_branch,
                                       optional: true),
          FastlaneCore::ConfigItem.new(key: :target,
                                       env_name: "GITLAB_MERGE_REQUEST_TARGET_BRANCH",
                                       description: "The name of the branch you want your changes pulled into (defaults to `master`)",
                                       is_string: true,
                                       default_value: 'master',
                                       optional: true),
          FastlaneCore::ConfigItem.new(key: :api_url,
                                       env_name: "GITLAB_MERGE_REQUEST_API_URL",
                                       description: "The URL of GitLab API",
                                       is_string: true,
                                       default_value: 'https://gitlab.com/api/v3',
                                       optional: true)
        ]
      end

      def self.output
        [
          ['CREATE_MERGE_REQUEST_WEB_URL', 'Web url of the merge request that we created.']
        ]
      end

      def self.return_value
        # If you method provides a return value, you can describe here what it does
      end

      def self.authors
        ['Yiming Tang']
      end

      def self.is_supported?(platform)
        return true
      end

       def self.example_code
        [
          'create_merge_request(
            api_token: ENV["GITLAB_TOKEN"],
            project_id: "100",
            target_project_id: "90"
            title: "Amazing new feature",
            source: "my-feature",                 # optional, defaults to current branch name
            target: "master",                     # optional, defaults to "master"
            body: "Please pull this in!",         # optional
            api_url: "http://yourdomain/api/v3"   # optional
          )'
        ]
      end

      def self.category
        :source_control
      end
    end
  end
end