Add config option underscore_flagslbriais-feature/add_config_for_underscore_switch

The default behaviour of translation flags-with-dashes is to underscore
them so they're symbol friendly. This config option allows us to avoid
this translation and simply return the flags verbatim:

    opts = Slop.parse(underscore_flags: false) do |o|
      o.on "--foo-bar"
    end

    opts.to_hash #=> { :"foo-bar" => true }

closes #204

4 files changed, 22 insertions, 5 deletions

diff --git a/lib/slop/option.rb b/lib/slop/option.rb
index 3e414f9..b8533ae 100644
--- a/lib/slop/option.rb
+++ b/lib/slop/option.rb
@@ -3,6 +3,7 @@ module Slop
     DEFAULT_CONFIG = {
       help: true,
       tail: false,
+      underscore_flags: true,
     }
 
     # An Array of flags this option matches.
@@ -107,7 +108,14 @@ module Slop
 
     # Returns the last key as a symbol. Used in Options.to_hash.
     def key
-      (config[:key] || flags.last.sub(/\A--?/, '')).tr("-", "_").to_sym
+      key = config[:key] || flags.last.sub(/\A--?/, '')
+      key = key.tr '-', '_' if underscore_flags?
+      key.to_sym
+    end
+
+    # Returns true if this option should be displayed with dashes transformed into underscores.
+    def underscore_flags?
+      config[:underscore_flags]
     end
 
     # Returns true if this option should be displayed in help text.
diff --git a/lib/slop/options.rb b/lib/slop/options.rb
index b739c5e..94fc5dd 100644
--- a/lib/slop/options.rb
+++ b/lib/slop/options.rb
@@ -3,9 +3,10 @@ module Slop
     include Enumerable
 
     DEFAULT_CONFIG = {
-      suppress_errors: false,
-      type:            "null",
-      banner:          true,
+      suppress_errors:  false,
+      type:             "null",
+      banner:           true,
+      underscore_flags: true,
     }
 
     # The Array of Option instances we've created.
diff --git a/lib/slop/result.rb b/lib/slop/result.rb
index 6f56248..469d05c 100644
--- a/lib/slop/result.rb
+++ b/lib/slop/result.rb
@@ -33,7 +33,11 @@ module Slop
 
     # Returns an Option if it exists. Ignores any prefixed hyphens.
     def option(flag)
-      cleaned = -> (f) { f.to_s.sub(/\A--?/, '').tr('_', '-') }
+      cleaned = -> (f) do
+        key = f.to_s.sub(/\A--?/, '')
+        key = key.tr '-', '_' if parser.config[:underscore_flags]
+        key.to_sym
+      end
       options.find do |o|
         o.flags.any? { |f| cleaned.(f) == cleaned.(flag) }
       end
diff --git a/test/option_test.rb b/test/option_test.rb
index 78fd55e..a8db657 100644
--- a/test/option_test.rb
+++ b/test/option_test.rb
@@ -21,6 +21,10 @@ describe Slop::Option do
       assert_equal :foo_bar, option(%w(-f --foo-bar), nil).key
     end
 
+    it "when specified, it won't convert dashes to underscores to make multi-word options symbol-friendly" do
+      assert_equal :'foo-bar', option(%w(-f --foo-bar), nil, underscore_flags: false).key
+    end
+
     it "can be overridden" do
       assert_equal :bar, option(%w(-f --foo), nil, key: "bar").key
     end