Add command validation

Author: hoppergee

lib/matrixeval/ruby/command_line.rb

@@ -12,6 +12,12 @@ def initialize(argv)
         @argv = argv
       end
 
+      def valid?
+        init? ||
+          !context_options.empty? ||
+          !seperator_index.nil?
+      end
+
       def init?
         argv[0] == 'init'
       end

lib/matrixeval/ruby/runner.rb

@@ -23,19 +23,37 @@ def initialize(argv)
       end
 
       def start
+        validates
+
         if command.init?
           init
         elsif command.all?
           run_all_contexts
         else
           run_a_specific_context
         end
+      rescue OptionParser::InvalidOption => e
+        puts <<~ERROR
+          #{e.message}
+          See 'matrixeval --help'
+          ERROR
+        exit
       ensure
         turn_on_stty_opost
       end
 
       private
 
+      def validates
+        return if command.valid?
+
+        puts <<~ERROR
+          matrixeval: '#{argv.join(' ')}' is not a MatrixEval command.
+          See 'matrixeval --help'
+          ERROR
+        exit
+      end
+
       def init
         Config::YAML.create
         Gitignore.update