From 216378ef77fb1b4d99cc154d6e166faf9a2d44b5 Mon Sep 17 00:00:00 2001
From: Parker Moore <parkrmoore@gmail.com>
Date: Thu, 20 Feb 2014 18:14:37 -0500
Subject: [PATCH] Add -t and --trace to Command's default flags

---
 examples/trace.rb        | 21 +++++++++++++++++++++
 lib/mercenary/command.rb | 20 +++++++++++++-------
 lib/mercenary/program.rb | 11 ++++++++++-
 3 files changed, 44 insertions(+), 8 deletions(-)
 create mode 100644 examples/trace.rb

diff --git a/examples/trace.rb b/examples/trace.rb
new file mode 100644
index 0000000..0aaa365
--- /dev/null
+++ b/examples/trace.rb
@@ -0,0 +1,21 @@
+#!/usr/bin/env ruby
+
+$:.unshift File.join(File.dirname(__FILE__), *%w{ .. lib })
+
+require "mercenary"
+
+# This example sets the logging mode of mercenary to
+# debug. Logging messages from "p.logger.debug" will
+# be output to STDOUT.
+
+Mercenary.program(:trace) do |p|
+
+  p.version "2.0.1"
+  p.description 'An example of traces in Mercenary'
+  p.syntax 'trace <subcommand>'
+
+  p.action do |_, _|
+    raise ArgumentError.new("YOU DID SOMETHING TERRIBLE YOU BUFFOON")
+  end
+
+end
diff --git a/lib/mercenary/command.rb b/lib/mercenary/command.rb
index 75953d2..f18d3a3 100644
--- a/lib/mercenary/command.rb
+++ b/lib/mercenary/command.rb
@@ -8,6 +8,7 @@ class Command
     attr_accessor :actions
     attr_reader :map
     attr_accessor :parent
+    attr_reader :trace
 
     # Public: Creates a new Command
     #
@@ -17,12 +18,13 @@ class Command
     #
     # Returns nothing
     def initialize(name, parent = nil)
-      @name = name
-      @options = []
-      @commands =  {}
-      @actions = []
-      @map = {}
-      @parent = parent
+      @name     = name
+      @options  = []
+      @commands = {}
+      @actions  = []
+      @map      = {}
+      @parent   = parent
+      @trace    = false
     end
 
     # Public: Sets or gets the command version
@@ -133,7 +135,7 @@ def logger(level = nil)
         @logger = Logger.new(STDOUT)
         @logger.level = level || Logger::INFO
         @logger.formatter = proc do |severity, datetime, progname, msg|
-          "#{ident} (#{severity}): #{msg}\n"
+          "#{identity} (#{severity}): #{msg}\n"
         end
       end
 
@@ -191,6 +193,10 @@ def add_default_options(opts)
         abort
       end
 
+      opts.on('-t', '--trace', 'Show full backtrace if an error occurs') do
+        @trace = true
+      end
+
       opts.on_tail("-h", "--help", "Show this message") do
         puts self
         exit
diff --git a/lib/mercenary/program.rb b/lib/mercenary/program.rb
index 192a384..73d9b96 100644
--- a/lib/mercenary/program.rb
+++ b/lib/mercenary/program.rb
@@ -31,7 +31,16 @@ def go(argv)
 
       logger.debug("Parsed config: #{@config.inspect}")
 
-      cmd.execute(argv, @config)
+      begin
+        cmd.execute(argv, @config)
+      rescue => e
+        if cmd.trace
+          raise e
+        else
+          logger.error e.message
+          abort
+        end
+      end
     end
   end
 end