refactor(command, executor): deprecate pre_run Bool? overload

src/cling/command.cr

@@ -180,9 +180,6 @@ module Cling
     # This has access to the parsed arguments and options from the command line. This is useful if
     # you want to implement checks for specific flags outside of the main `run` method, such as
     # `-v`/`--version` flags or `-h`/`--help` flags.
-    #
-    # Accepts a `Bool` or `nil` argument as a return to specify whether the command should continue
-    # to run once finished (`true` or `nil` to continue, `false` to stop).
     def pre_run(arguments : Arguments, options : Options) : Bool?
     end
 

src/cling/executor.cr

@@ -50,7 +50,10 @@ module Cling::Executor
     end
 
     begin
-      resolved_command.pre_run executed.parsed_arguments, executed.parsed_options
+      deprecation_helper(
+        resolved_command,
+        resolved_command.pre_run(executed.parsed_arguments, executed.parsed_options)
+      )
     rescue ex : ExitProgram
       return handle_exit ex
     rescue ex
@@ -69,6 +72,14 @@ module Cling::Executor
     end
   end
 
+  private def self.deprecation_helper(type : T, value : Bool?) : Nil forall T
+    {% T.warning "#{T}#pre_run : Bool? is deprecated. Use `pre_run(arguments : Arguments, options : Options) : Nil` instead" %}
+    raise ExitProgram.new 1 if value == false
+  end
+
+  private def self.deprecation_helper(type : T, value : Nil) : Nil forall T
+  end
+
   private def self.resolve_command(command : Command, results : Array(Parser::Result)) : Command?
     arguments = results.select { |r| r.kind.argument? && !r.string? }
     return command if arguments.empty? || command.children.empty?