Add commands to start and use the debugger

lib/irb.rb

@@ -427,7 +427,7 @@ def initialize(workspace = nil, input_method = nil)
       @context = Context.new(self, workspace, input_method)
       @context.main.extend ExtendCommandBundle
       @context.command_aliases.each do |alias_name, cmd_name|
-        next if @context.symbol_alias(alias_name)
+        next if @context.symbol_alias?(alias_name) || @context.main.respond_to?(alias_name)
         @context.main.install_alias_method(alias_name, cmd_name)
       end
       @signal_status = :IN_IRB

lib/irb/cmd/break.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+require_relative "debug"
+
+module IRB
+  # :stopdoc:
+
+  module ExtendCommand
+    class Break < Debug
+      def execute(*args)
+        super(['break', *args].join(' '))
+      end
+    end
+  end
+
+  # :startdoc:
+end

lib/irb/cmd/continue.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+require_relative "debug"
+
+module IRB
+  # :stopdoc:
+
+  module ExtendCommand
+    class Continue < Debug
+      def execute(*args)
+        super(['continue', *args].join(' '))
+      end
+    end
+  end
+
+  # :startdoc:
+end

lib/irb/cmd/debug.rb

@@ -11,7 +11,7 @@ class Debug < Nop
       ].map { |file| /\A#{Regexp.escape(file)}:\d+:in `irb'\z/ }
       IRB_DIR = File.expand_path('..', __dir__)
 
-      def execute(*args)
+      def execute(debug_command = nil)
         unless binding_irb?
           puts "`debug` command is only available when IRB is started with binding.irb"
           return
@@ -25,11 +25,16 @@ def execute(*args)
           return
         end
 
+        command = nil
+        if debug_command
+          command = ['irb', nil, debug_command]
+        end
+
         # To make debugger commands like `next` or `continue` work without asking
         # the user to quit IRB after that, we need to exit IRB first and then hit
         # a TracePoint on #debug_break.
         file, lineno = IRB::Irb.instance_method(:debug_break).source_location
-        DEBUGGER__::SESSION.add_line_breakpoint(file, lineno + 1, oneshot: true, hook_call: false)
+        DEBUGGER__::SESSION.add_line_breakpoint(file, lineno + 1, oneshot: true, hook_call: false, command: command)
         # exit current Irb#run call
         throw :IRB_EXIT
       end

lib/irb/cmd/finish.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+require_relative "debug"
+
+module IRB
+  # :stopdoc:
+
+  module ExtendCommand
+    class Finish < Debug
+      def execute(*args)
+        super(['finish', *args].join(' '))
+      end
+    end
+  end
+
+  # :startdoc:
+end

lib/irb/cmd/next.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+require_relative "debug"
+
+module IRB
+  # :stopdoc:
+
+  module ExtendCommand
+    class Next < Debug
+      def execute(*args)
+        super(['next', *args].join(' '))
+      end
+    end
+  end
+
+  # :startdoc:
+end

lib/irb/context.rb

@@ -486,9 +486,9 @@ def evaluate(line, line_no, exception: nil) # :nodoc:
         @workspace.local_variable_set(:_, exception)
       end
 
-      # Transform a non-identifier alias (ex: @, $)
+      # Transform a non-identifier alias (@, $) or keywords (next, break)
       command, args = line.split(/\s/, 2)
-      if original = symbol_alias(command)
+      if original = command_aliases[command.to_sym]
         line = line.gsub(/\A#{Regexp.escape(command)}/, original.to_s)
         command = original
       end
@@ -546,9 +546,9 @@ def local_variables # :nodoc:
     end
 
     # Return a command name if it's aliased from the argument and it's not an identifier.
-    def symbol_alias(command)
+    def symbol_alias?(command)
       return nil if command.match?(/\A\w+\z/)
-      command_aliases[command.to_sym]
+      command_aliases.key?(command.to_sym)
     end
   end
 end

lib/irb/extend-command.rb

@@ -120,6 +120,21 @@ def irb_context
         :irb_debug, :Debug, "cmd/debug",
         [:debug, NO_OVERRIDE],
       ],
+      [
+        :irb_break, :Break, "cmd/break",
+      ],
+      [
+        :irb_next, :Next, "cmd/next",
+      ],
+      [
+        :irb_continue, :Continue, "cmd/continue",
+        [:continue, NO_OVERRIDE],
+      ],
+      [
+        :irb_finish, :Finish, "cmd/finish",
+        [:finish, NO_OVERRIDE],
+      ],
+
       [
         :irb_help, :Help, "cmd/help",
         [:help, NO_OVERRIDE],

lib/irb/init.rb

@@ -160,8 +160,12 @@ def IRB.init_config(ap_path)
     @CONF[:AT_EXIT] = []
 
     @CONF[:COMMAND_ALIASES] = {
+      # Symbol aliases
       :'$' => :show_source,
       :'@' => :whereami,
+      # Keyword aliases
+      :break => :irb_break,
+      :next => :irb_next,
     }
   end
 

lib/irb/ruby-lex.rb

@@ -67,7 +67,7 @@ def set_input(io, p = nil, context:, &block)
         else
           # Accept any single-line input starting with a non-identifier alias (ex: @, $)
           command = code.split(/\s/, 2).first
-          if context.symbol_alias(command)
+          if context.symbol_alias?(command)
             next true
           end