Show descriptions for all commands in Rails help

When calling `rails help` most commands missed their description. We now
show the same descriptions as shown in `rails -T`.

We can show the description after the command name and use some padding
to align the descriptions. Lines are truncated to the width of the
terminal.

Rails::Command had logic for printing help commands not in 'usage':
`print_commands`, `commands` and the `COMMANDS_IN_USAGE` constant. As
these methods were only used by Rails::Command::HelpCommand, they have
been moved HelpCommand.

This also changes the `printing_commands` methods on several classes.
Instead of returning just the commands, they return the commands
with the descriptions. As these are only used for printing help it does
not affect any other code.

Some commands (routes, credentials:diff, etc) show no description yet,
but these can be added later.

Author: p8

railties/CHANGELOG.md

@@ -1,3 +1,10 @@
+*   Show descriptions for all commands in Rails help
+
+    When calling `rails help` most commands missed their description. We now
+    show the same descriptions as shown in `rails -T`.
+
+    *Petrik de Heus*
+
 *   Always generate the storage/ directory with rails new to ensure there's a stable place to
     put permanent files, and a single mount point for containers to map. Then default sqlite3 databases
     to live there instead of db/, which is only meant for configuration, not data.

railties/lib/rails/command.rb

@@ -86,8 +86,10 @@ def root
         end
       end
 
-      def print_commands # :nodoc:
-        commands.each { |command| puts("  #{command}") }
+      def printing_commands # :nodoc:
+        lookup!
+
+        (subclasses - hidden_commands).flat_map(&:printing_commands)
       end
 
       private

railties/lib/rails/command/base.rb

@@ -92,7 +92,7 @@ def perform(command, args, config) # :nodoc:
         end
 
         def printing_commands
-          namespaced_commands
+          namespaced_commands.map { |command| [command, ""] }
         end
 
         def executable(subcommand = nil)

railties/lib/rails/commands/help/help_command.rb

@@ -8,8 +8,19 @@ class HelpCommand < Base # :nodoc:
       def help(*)
         say self.class.desc
 
-        Rails::Command.print_commands
+        other_commands = printing_commands_not_in_usage.sort_by(&:first)
+        print_table(other_commands, indent: 1, truncate: true)
       end
+
+      private
+        COMMANDS_IN_USAGE = %w(generate console server test test:system dbconsole new)
+        private_constant :COMMANDS_IN_USAGE
+
+        def printing_commands_not_in_usage # :nodoc:
+          Rails::Command.printing_commands.reject do |command, _|
+            command.in?(COMMANDS_IN_USAGE)
+          end
+        end
     end
   end
 end

railties/lib/rails/commands/rake/rake_command.rb

@@ -9,7 +9,7 @@ class RakeCommand < Base # :nodoc:
 
       class << self
         def printing_commands
-          formatted_rake_tasks.map(&:first)
+          formatted_rake_tasks
         end
 
         def perform(task, args, config)

railties/test/command/base_test.rb

@@ -8,9 +8,9 @@
 
 class Rails::Command::BaseTest < ActiveSupport::TestCase
   test "printing commands" do
-    assert_equal %w(generate), Rails::Command::GenerateCommand.printing_commands
-    assert_equal %w(secrets:setup secrets:edit secrets:show), Rails::Command::SecretsCommand.printing_commands
-    assert_equal %w(db:system:change), Rails::Command::Db::System::ChangeCommand.printing_commands
+    assert_equal [["generate", ""]], Rails::Command::GenerateCommand.printing_commands
+    assert_equal [["secrets:setup", ""], ["secrets:edit", ""], ["secrets:show", ""]], Rails::Command::SecretsCommand.printing_commands
+    assert_equal [["db:system:change", ""]], Rails::Command::Db::System::ChangeCommand.printing_commands
   end
 
   test "printing commands hides hidden commands" do