Add support for subcommands to the help command.

app/assets/stylesheets/application.tailwind.css

@@ -65,7 +65,8 @@
 }
 
 #messages .message-alias td,
-#messages .message-help td {
+#messages .message-help td,
+#messages .message-help th {
   @apply py-2 px-4 font-normal text-left border-0 bg-inherit;
 }
 
@@ -151,7 +152,7 @@
 }
 
 #messages .message-alias td[colspan="2"],
-#messages .message-help td[colspan="3"] {
+#messages .message-help th {
   @apply font-sans font-bold text-center bg-slate-200;
 }
 

app/services/commands/help.rb

@@ -2,13 +2,37 @@
 
 module Commands
   class Help < Base
+    argument name: 0
+
     private
 
+    # Return the command name with forward slashes removed.
+    #
+    # @return [String]
+    def name
+      @name ||= parameters[:name].to_s.tr("/", "")
+    end
+
     # Return the handler for a successful command execution.
     #
-    # @return [Success]
+    # @return [Command] When a valid command name is provided.
+    # @return [List] When no command name is provided.
     def success
-      Success.new
+      if name.present?
+        Command.new(name: name)
+      else
+        List.new
+      end
+    end
+
+    # Validate a command when present.
+    #
+    # @return [InvalidCommand] If the command is invalid.
+    # @return [nil] If the command is blank or valid.
+    def validate_name
+      if name.present? && !I18n.exists?("commands.help.commands.#{name}")
+        InvalidCommand.new(name: name)
+      end
     end
   end
 end

app/services/commands/help/command.rb

@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+module Commands
+  class Help < Base
+    class Command < Result
+      locals :commands
+
+      # Initialize a help command result.
+      #
+      # @return [void]
+      def initialize(name:)
+        @name = name
+      end
+
+      private
+
+      attr_reader :name
+
+      # Return help for the single command.
+      #
+      # @return [Array]
+      def command
+        [I18n.t(key).merge(name: name)]
+      end
+
+      # Return help for the subcommands or the command itself.
+      #
+      # @return [Array]
+      def commands
+        subcommands || command
+      end
+
+      # Return the I18n key for the command name.
+      #
+      # @return [String]
+      def key
+        "commands.help.commands.#{name}"
+      end
+
+      # Return the help list partial path.
+      #
+      # @return [String]
+      def partial
+        "commands/help/list"
+      end
+
+      # Return help for the subcommands, if any.
+      #
+      # @return [Array] When subcommands exist.
+      # @return [nil] When subcommands do not exist.
+      def subcommands
+        if I18n.exists?("#{key}.subcommands")
+          I18n
+            .t("#{key}.subcommands")
+            .each.with_object([]) do |(subcommand, details), result|
+              result << details.merge(
+                arguments: "#{subcommand} #{details[:arguments]}".strip,
+                name:      name
+              )
+            end
+        end
+      end
+    end
+  end
+end

app/services/commands/help/invalid_command.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+module Commands
+  class Help < Base
+    class InvalidCommand < Result
+      locals :name
+
+      # Initialize a help invalid command result.
+      #
+      # @return [void]
+      def initialize(name:)
+        @name = name
+      end
+    end
+  end
+end

app/services/commands/help/success.rb → app/services/commands/help/list.rb

@@ -2,7 +2,7 @@
 
 module Commands
   class Help < Base
-    class Success < Result
+    class List < Result
       locals :commands
 
       delegate :commands, to: :class

app/views/commands/help/_invalid_command.html.erb

@@ -0,0 +1,7 @@
+<%# locals: (name:) %>
+<tr data-chat-target="message">
+  <td class="message-help-invalid-command"></td>
+  <td class="message-help-invalid-command">
+    <%= t(".message", name: name) %>
+  </td>
+</tr>

app/views/commands/help/_invalid_command.turbo_stream.erb

@@ -0,0 +1,2 @@
+<%# locals: (name:) %>
+<%= turbo_stream.append("messages", partial: "commands/help/invalid_command", locals: { name: name }) %>

app/views/commands/help/_success.html.erb → app/views/commands/help/_list.html.erb

@@ -3,7 +3,8 @@
   <td colspan="2" class="message-help">
     <table>
       <tr>
-        <td colspan="3"><%= t(".header") %></td>
+        <th colspan="2"><%= t(".command") %></td>
+        <th><%= t(".description") %></td>
       </tr>
 
       <% commands.each do |command| %>

app/views/commands/help/_list.turbo_stream.erb

@@ -0,0 +1,2 @@
+<%# locals: (commands:) %>
+<%= turbo_stream.append("messages", partial: "commands/help/list", locals: { commands: commands }) %>

config/locales/en.yml

@@ -123,7 +123,20 @@ en:
     help:
       commands:
         alias:
-          description: "List the available command aliases."
+          arguments: "(add|list|remove|show)"
+          description: "Manage the command aliases for your account."
+          subcommands:
+            add:
+              arguments: "[alias] [command]"
+              description: "Add a new command alias."
+            list:
+              description: "List all available command aliases."
+            remove:
+              arguments: "[alias]"
+              description: "Remove a command alias."
+            show:
+              arguments: "[alias]"
+              description: "Show a command alias."
         attack:
           arguments: "[target]"
           description: "Attempt to attack a target."
@@ -133,6 +146,9 @@ en:
         emote:
           arguments: "[message]"
           description: "Emote a message to the room."
+        help:
+          arguments: "[command]"
+          description: "Display help for commands, or a specific command."
         look:
           description: "Look at the room."
         move:
@@ -144,8 +160,11 @@ en:
         whisper:
           arguments: "[name] [message]"
           description: "Whisper a message to a character in the room."
-      success:
-        header: "Available Commands"
+      invalid_command:
+        message: "There is no \"%{name}\" command."
+      list:
+        command: "Command"
+        description: "Description"
     look:
       unknown: "You don't see %{article} %{target} here."
     lookup:

spec/features/commands/help_spec.rb

@@ -30,9 +30,66 @@
     end
   end
 
+  context "with a valid command" do
+    let(:command) { "/help /#{name}" }
+    let(:name)    { "alias" }
+
+    it "displays the help command message to the sender" do
+      send_text(command)
+
+      expect(page).to have_help_command_message
+    end
+
+    it "does not broadcast the message to the room" do
+      using_session(:nearby_character) do
+        sign_in_as_character create(:character, room: character.room)
+      end
+
+      send_text(command)
+
+      wait_for(have_help_command_message) do
+        using_session(:nearby_character) do
+          expect(page).not_to have_help_command_message
+        end
+      end
+    end
+  end
+
+  context "with an invalid command" do
+    let(:command) { "/help /#{name}" }
+    let(:name)    { "fake" }
+
+    it "displays invalid command message to the sender" do
+      send_text(command)
+
+      expect(page).to have_invalid_command_message(command: name)
+    end
+
+    it "does not broadcast the message to the room" do
+      using_session(:nearby_character) do
+        sign_in_as_character create(:character, room: character.room)
+      end
+
+      send_text(command)
+
+      wait_for(have_invalid_command_message(command: name)) do
+        using_session(:nearby_character) do
+          expect(page).not_to have_invalid_command_message(command: name)
+        end
+      end
+    end
+  end
+
   protected
 
   def have_help_command_message
     have_css("#messages .message-help")
   end
+
+  def have_invalid_command_message(command:)
+    have_css(
+      "#messages .message-help-invalid-command",
+      text: t("commands.help.invalid_command.message", name: command)
+    )
+  end
 end

spec/services/commands/help/command_spec.rb

@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+describe Commands::Help::Command, type: :service do
+  describe "class" do
+    it "inherits from command result" do
+      expect(described_class.superclass).to eq(Commands::Result)
+    end
+  end
+
+  describe "#locals" do
+    subject(:locals) { instance.locals }
+
+    let(:instance) { described_class.new(name: name) }
+
+    context "with a command without subcommands" do
+      let(:name) { "help" }
+
+      it "returns the command details" do
+        expect(locals).to eq(
+          commands: [
+            {
+              arguments:   t("commands.help.commands.help.arguments"),
+              description: t("commands.help.commands.help.description"),
+              name:        name
+            }
+          ]
+        )
+      end
+    end
+
+    context "with a command with subcommands" do
+      let(:name) { "alias" }
+
+      it "returns the command details" do # rubocop:disable RSpec/ExampleLength
+        expect(locals).to eq(
+          commands: [
+            {
+              arguments:   "add [alias] [command]",
+              description: t("commands.help.commands.alias.subcommands.add.description"),
+              name:        "alias"
+            },
+            {
+              arguments:   "list",
+              description: t("commands.help.commands.alias.subcommands.list.description"),
+              name:        "alias"
+            },
+            {
+              arguments:   "remove [alias]",
+              description: t("commands.help.commands.alias.subcommands.remove.description"),
+              name:        "alias"
+            },
+            {
+              arguments:   "show [alias]",
+              description: t("commands.help.commands.alias.subcommands.show.description"),
+              name:        "alias"
+            }
+          ]
+        )
+      end
+    end
+  end
+
+  describe "#partial" do
+    subject { instance.render_options[:partial] }
+
+    let(:instance) { described_class.new(name: "help") }
+
+    it { is_expected.to eq("commands/help/list") }
+  end
+end

spec/services/commands/help/invalid_command_spec.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+require "rails_helper"
+
+describe Commands::Help::InvalidCommand, type: :service do
+  describe "class" do
+    it "inherits from command result" do
+      expect(described_class.superclass).to eq(Commands::Result)
+    end
+  end
+
+  describe "#locals" do
+    subject { instance.locals }
+
+    let(:instance) { described_class.new(name: name) }
+    let(:name)     { double }
+
+    it { is_expected.to eq(name: name) }
+  end
+end

spec/services/commands/help/success_spec.rb → spec/services/commands/help/list_spec.rb

@@ -2,7 +2,7 @@
 
 require "rails_helper"
 
-describe Commands::Help::Success, type: :service do
+describe Commands::Help::List, type: :service do
   describe "class" do
     it { is_expected.to delegate_method(:commands).to(:class) }