Merge pull request #390 from developingchris/boolean_negative

document negative option for boolean option

lib/thor/parser/option.rb

@@ -85,6 +85,10 @@ def usage(padding = 0)
 
       sample = "[#{sample}]" unless required?
 
+      if boolean?
+        sample << ", [#{dasherize("no-" + human_name)}]" unless name == "force"
+      end
+
       if aliases.empty?
         (' ' * padding) << sample
       else

spec/parser/option_spec.rb

@@ -172,11 +172,15 @@ def option(name, options = {})
     end
 
     it 'returns usage for boolean types' do
-      expect(parse(:foo, :boolean).usage).to eq('[--foo]')
+      expect(parse(:foo, :boolean).usage).to eq('[--foo], [--no-foo]')
     end
 
     it 'does not use padding when no aliases are given' do
-      expect(parse(:foo, :boolean).usage).to eq('[--foo]')
+      expect(parse(:foo, :boolean).usage).to eq('[--foo], [--no-foo]')
+    end
+
+    it 'documents a negative option when boolean' do
+      expect(parse(:foo, :boolean).usage).to include('[--no-foo]')
     end
 
     it 'uses banner when supplied' do
@@ -197,6 +201,10 @@ def option(name, options = {})
       it 'does not show the usage between brackets' do
         expect(parse([:foo, '-f', '-b'], :required).usage).to eq('-f, -b, --foo=FOO')
       end
+
+      it 'does not negate the aliases' do
+        expect(parse([:foo, '-f', '-b'], :boolean).usage).to eq('-f, -b, [--foo], [--no-foo]')
+      end
     end
   end
 end