[ruby/irb] Command implementation not by method

(ruby/irb#824)

* Command is not a method

* Fix command test

* Implement non-method command name completion

* Add test for ExtendCommandBundle.def_extend_command

* Add helper method install test

* Remove spaces in command input parse

* Remove command arg unquote in help command

* Simplify Statement and handle execution in IRB::Irb

* Tweak require, const name

* Always install CommandBundle module to main object

* Remove considering local variable in command or expression check

* Remove unused method, tweak

* Remove outdated comment for help command arg

Co-authored-by: Stan Lo <stan001212@gmail.com>

---------

ruby/irb@8fb776e379

Co-authored-by: Stan Lo <stan001212@gmail.com>

lib/irb.rb

@@ -929,7 +929,7 @@ class Irb
     # Creates a new irb session
     def initialize(workspace = nil, input_method = nil)
       @context = Context.new(self, workspace, input_method)
-      @context.workspace.load_commands_to_main
+      @context.workspace.load_helper_methods_to_main
       @signal_status = :IN_IRB
       @scanner = RubyLex.new
       @line_no = 1
@@ -950,7 +950,7 @@ def debug_break
     def debug_readline(binding)
       workspace = IRB::WorkSpace.new(binding)
       context.replace_workspace(workspace)
-      context.workspace.load_commands_to_main
+      context.workspace.load_helper_methods_to_main
       @line_no += 1
 
       # When users run:
@@ -1028,7 +1028,15 @@ def eval_input
               return statement.code
             end
 
-            @context.evaluate(statement.evaluable_code, line_no)
+            case statement
+            when Statement::EmptyInput
+              # Do nothing
+            when Statement::Expression
+              @context.evaluate(statement.code, line_no)
+            when Statement::Command
+              ret = statement.command_class.execute(@context, statement.arg)
+              @context.set_last_value(ret)
+            end
 
             if @context.echo? && !statement.suppresses_echo?
               if statement.is_assignment?
@@ -1084,10 +1092,7 @@ def readmultiline
         end
 
         code << line
-
-        # Accept any single-line input for symbol aliases or commands that transform
-        # args
-        return code if single_line_command?(code)
+        return code if command?(code)
 
         tokens, opens, terminated = @scanner.check_code_state(code, local_variables: @context.local_variables)
         return code if terminated
@@ -1114,23 +1119,36 @@ def build_statement(code)
       end
 
       code.force_encoding(@context.io.encoding)
-      command_or_alias, arg = code.split(/\s/, 2)
-      # Transform a non-identifier alias (@, $) or keywords (next, break)
-      command_name = @context.command_aliases[command_or_alias.to_sym]
-      command = command_name || command_or_alias
-      command_class = ExtendCommandBundle.load_command(command)
-
-      if command_class
-        Statement::Command.new(code, command, arg, command_class)
+      if (command, arg = parse_command(code))
+        command_class = ExtendCommandBundle.load_command(command)
+        Statement::Command.new(code, command_class, arg)
       else
         is_assignment_expression = @scanner.assignment_expression?(code, local_variables: @context.local_variables)
         Statement::Expression.new(code, is_assignment_expression)
       end
     end
 
-    def single_line_command?(code)
-      command = code.split(/\s/, 2).first
-      @context.symbol_alias?(command) || @context.transform_args?(command)
+    def parse_command(code)
+      command_name, arg = code.strip.split(/\s+/, 2)
+      return unless code.lines.size == 1 && command_name
+
+      arg ||= ''
+      command = command_name.to_sym
+      # Command aliases are always command. example: $, @
+      if (alias_name = @context.command_aliases[command])
+        return [alias_name, arg]
+      end
+
+      # Check visibility
+      public_method = !!Kernel.instance_method(:public_method).bind_call(@context.main, command) rescue false
+      private_method = !public_method && !!Kernel.instance_method(:method).bind_call(@context.main, command) rescue false
+      if ExtendCommandBundle.execute_as_command?(command, public_method: public_method, private_method: private_method)
+        [command, arg]
+      end
+    end
+
+    def command?(code)
+      !!parse_command(code)
     end
 
     def configure_io
@@ -1148,9 +1166,7 @@ def configure_io
               false
             end
           else
-            # Accept any single-line input for symbol aliases or commands that transform
-            # args
-            next true if single_line_command?(code)
+            next true if command?(code)
 
             _tokens, _opens, terminated = @scanner.check_code_state(code, local_variables: @context.local_variables)
             terminated

lib/irb/command.rb

@@ -12,29 +12,17 @@ module Command; end
 
   # Installs the default irb extensions command bundle.
   module ExtendCommandBundle
-    EXCB = ExtendCommandBundle # :nodoc:
-
-    # See #install_alias_method.
+    # See ExtendCommandBundle.execute_as_command?.
     NO_OVERRIDE = 0
-    # See #install_alias_method.
     OVERRIDE_PRIVATE_ONLY = 0x01
-    # See #install_alias_method.
     OVERRIDE_ALL = 0x02
 
-    # Displays current configuration.
-    #
-    # Modifying the configuration is achieved by sending a message to IRB.conf.
-    def irb_context
-      IRB.CurrentContext
-    end
-
-    @ALIASES = [
-      [:context, :irb_context, NO_OVERRIDE],
-      [:conf, :irb_context, NO_OVERRIDE],
-    ]
-
-
     @EXTEND_COMMANDS = [
+      [
+        :irb_context, :Context, "command/context",
+        [:context, NO_OVERRIDE],
+        [:conf, NO_OVERRIDE],
+      ],
       [
         :irb_exit, :Exit, "command/exit",
         [:exit, OVERRIDE_PRIVATE_ONLY],
@@ -204,6 +192,26 @@ def irb_context
       ],
     ]
 
+    def self.command_override_policies
+      @@command_override_policies ||= @EXTEND_COMMANDS.flat_map do |cmd_name, cmd_class, load_file, *aliases|
+        [[cmd_name, OVERRIDE_ALL]] + aliases
+      end.to_h
+    end
+
+    def self.execute_as_command?(name, public_method:, private_method:)
+      case command_override_policies[name]
+      when OVERRIDE_ALL
+        true
+      when OVERRIDE_PRIVATE_ONLY
+        !public_method
+      when NO_OVERRIDE
+        !public_method && !private_method
+      end
+    end
+
+    def self.command_names
+      command_override_policies.keys.map(&:to_s)
+    end
 
     @@commands = []
 
@@ -247,77 +255,13 @@ def self.load_command(command)
       nil
     end
 
-    # Installs the default irb commands.
-    def self.install_extend_commands
-      for args in @EXTEND_COMMANDS
-        def_extend_command(*args)
-      end
-    end
-
-    # Evaluate the given +cmd_name+ on the given +cmd_class+ Class.
-    #
-    # Will also define any given +aliases+ for the method.
-    #
-    # The optional +load_file+ parameter will be required within the method
-    # definition.
     def self.def_extend_command(cmd_name, cmd_class, load_file, *aliases)
-      case cmd_class
-      when Symbol
-        cmd_class = cmd_class.id2name
-      when String
-      when Class
-        cmd_class = cmd_class.name
-      end
-
-      line = __LINE__; eval %[
-        def #{cmd_name}(*opts, **kwargs, &b)
-          Kernel.require_relative "#{load_file}"
-          ::IRB::Command::#{cmd_class}.execute(irb_context, *opts, **kwargs, &b)
-        end
-      ], nil, __FILE__, line
-
-      for ali, flag in aliases
-        @ALIASES.push [ali, cmd_name, flag]
-      end
-    end
-
-    # Installs alias methods for the default irb commands, see
-    # ::install_extend_commands.
-    def install_alias_method(to, from, override = NO_OVERRIDE)
-      to = to.id2name unless to.kind_of?(String)
-      from = from.id2name unless from.kind_of?(String)
+      @EXTEND_COMMANDS.delete_if { |name,| name == cmd_name }
+      @EXTEND_COMMANDS << [cmd_name, cmd_class, load_file, *aliases]
 
-      if override == OVERRIDE_ALL or
-          (override == OVERRIDE_PRIVATE_ONLY) && !respond_to?(to) or
-          (override == NO_OVERRIDE) &&  !respond_to?(to, true)
-        target = self
-        (class << self; self; end).instance_eval{
-          if target.respond_to?(to, true) &&
-            !target.respond_to?(EXCB.irb_original_method_name(to), true)
-            alias_method(EXCB.irb_original_method_name(to), to)
-          end
-          alias_method to, from
-        }
-      else
-        Kernel.warn "irb: warn: can't alias #{to} from #{from}.\n"
-      end
-    end
-
-    def self.irb_original_method_name(method_name) # :nodoc:
-      "irb_" + method_name + "_org"
-    end
-
-    # Installs alias methods for the default irb commands on the given object
-    # using #install_alias_method.
-    def self.extend_object(obj)
-      unless (class << obj; ancestors; end).include?(EXCB)
-        super
-        for ali, com, flg in @ALIASES
-          obj.install_alias_method(ali, com, flg)
-        end
-      end
+      # Just clear memoized values
+      @@commands = []
+      @@command_override_policies = nil
     end
-
-    install_extend_commands
   end
 end

lib/irb/command/backtrace.rb

@@ -7,12 +7,8 @@ module IRB
 
   module Command
     class Backtrace < DebugCommand
-      def self.transform_args(args)
-        args&.dump
-      end
-
-      def execute(*args)
-        super(pre_cmds: ["backtrace", *args].join(" "))
+      def execute(arg)
+        execute_debug_command(pre_cmds: "backtrace #{arg}".rstrip)
       end
     end
   end

lib/irb/command/base.rb

@@ -10,6 +10,10 @@ module IRB
   module Command
     class CommandArgumentError < StandardError; end
 
+    def self.extract_ruby_args(*args, **kwargs)
+      throw :EXTRACT_RUBY_ARGS, [args, kwargs]
+    end
+
     class Base
       class << self
         def category(category = nil)
@@ -29,19 +33,13 @@ def help_message(help_message = nil)
 
         private
 
-        def string_literal?(args)
-          sexp = Ripper.sexp(args)
-          sexp && sexp.size == 2 && sexp.last&.first&.first == :string_literal
-        end
-
         def highlight(text)
           Color.colorize(text, [:BOLD, :BLUE])
         end
       end
 
-      def self.execute(irb_context, *opts, **kwargs, &block)
-        command = new(irb_context)
-        command.execute(*opts, **kwargs, &block)
+      def self.execute(irb_context, arg)
+        new(irb_context).execute(arg)
       rescue CommandArgumentError => e
         puts e.message
       end
@@ -52,7 +50,26 @@ def initialize(irb_context)
 
       attr_reader :irb_context
 
-      def execute(*opts)
+      def unwrap_string_literal(str)
+        return if str.empty?
+
+        sexp = Ripper.sexp(str)
+        if sexp && sexp.size == 2 && sexp.last&.first&.first == :string_literal
+          @irb_context.workspace.binding.eval(str).to_s
+        else
+          str
+        end
+      end
+
+      def ruby_args(arg)
+        # Use throw and catch to handle arg that includes `;`
+        # For example: "1, kw: (2; 3); 4" will be parsed to [[1], { kw: 3 }]
+        catch(:EXTRACT_RUBY_ARGS) do
+          @irb_context.workspace.binding.eval "IRB::Command.extract_ruby_args #{arg}"
+        end || [[], {}]
+      end
+
+      def execute(arg)
         #nop
       end
     end

lib/irb/command/break.rb

@@ -7,12 +7,8 @@ module IRB
 
   module Command
     class Break < DebugCommand
-      def self.transform_args(args)
-        args&.dump
-      end
-
-      def execute(args = nil)
-        super(pre_cmds: "break #{args}")
+      def execute(arg)
+        execute_debug_command(pre_cmds: "break #{arg}".rstrip)
       end
     end
   end

lib/irb/command/catch.rb

@@ -7,12 +7,8 @@ module IRB
 
   module Command
     class Catch < DebugCommand
-      def self.transform_args(args)
-        args&.dump
-      end
-
-      def execute(*args)
-        super(pre_cmds: ["catch", *args].join(" "))
+      def execute(arg)
+        execute_debug_command(pre_cmds: "catch #{arg}".rstrip)
       end
     end
   end

lib/irb/command/chws.rb

@@ -14,7 +14,7 @@ class CurrentWorkingWorkspace < Base
       category "Workspace"
       description "Show the current workspace."
 
-      def execute(*obj)
+      def execute(_arg)
         irb_context.main
       end
     end
@@ -23,8 +23,13 @@ class ChangeWorkspace < Base
       category "Workspace"
       description "Change the current workspace to an object."
 
-      def execute(*obj)
-        irb_context.change_workspace(*obj)
+      def execute(arg)
+        if arg.empty?
+          irb_context.change_workspace
+        else
+          obj = eval(arg, irb_context.workspace.binding)
+          irb_context.change_workspace(obj)
+        end
         irb_context.main
       end
     end

lib/irb/command/context.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+module IRB
+  module Command
+    class Context < Base
+      category "IRB"
+      description "Displays current configuration."
+
+      def execute(_arg)
+        # This command just displays the configuration.
+        # Modifying the configuration is achieved by sending a message to IRB.conf.
+        Pager.page_content(IRB.CurrentContext.inspect)
+      end
+    end
+  end
+end