Allow to suppress automatic creation of --no-boolean flags

lib/thor.rb

@@ -151,6 +151,8 @@ def method_options(options = nil)
  # :type - The type of the argument, can be :string, :hash, :array, :numeric or :boolean.
  # :banner - String to show on usage notes.
  # :hide - If you want to hide this option from the help.
+ # :inverse - false if yo don't want an inverse option of your boolean type, String or Symbol
+ # if you want to override the inverse option name.
  #
  def method_option(name, options = {})
  scope = if options[:for]

lib/thor/parser/option.rb

@@ -13,6 +13,7 @@ def initialize(name, options = {})
  @group = options[:group].to_s.capitalize if options[:group]
  @aliases = Array(options[:aliases])
  @hide = options[:hide]
+ @inverse = options[:inverse]
  end
 
  # This parse quick options given as method_options. It makes several
@@ -81,17 +82,7 @@ def human_name
  end
 
  def usage(padding = 0)
- sample = if banner && !banner.to_s.empty?
- "#{switch_name}=#{banner}".dup
- else
- switch_name
- end
-
- sample = "[#{sample}]".dup unless required?
-
- if boolean?
- sample << ", [#{dasherize('no-' + human_name)}]" unless (name == "force") || name.start_with?("no-")
- end
+ sample = [ sample_banner, inverse_sample ].compact.join(", ")
 
  if aliases.empty?
  (" " * padding) << sample
@@ -110,6 +101,26 @@ def #{type}?
 
  protected
 
+ def sample_banner
+ sample_banner = if banner && !banner.to_s.empty?
+ "#{switch_name}=#{banner}".dup
+ else
+ switch_name
+ end
+ required? ? sample_banner : "[#{sample_banner}]"
+ end
+
+ def inverse_sample
+ return if !boolean? || name =~ /^(force|no-.*)$/
+
+ case @inverse
+ when Symbol, String
+ "[#{dasherize(@inverse.to_s)}]"
+ when nil, true
+ "[#{dasherize('no-' + human_name)}]"
+ end
+ end
+
  def validate!
  raise ArgumentError, "An option cannot be boolean and required." if boolean? && required?
  validate_default_type!

spec/parser/option_spec.rb

@@ -245,6 +245,22 @@ def option(name, options = {})
  expect(option(:foo, :required => false, :type => :string, :banner => "").usage).to eq("[--foo]")
  end
 
+ it "suppresses the creation of a --no-option when explicitly requested" do
+ expect(option("bar", type: :boolean, :inverse => false).usage).to_not include("[--no-bar]")
+ end
+
+ it "allow to override the inverse option" do
+ expect(option("colorful", type: :boolean, :inverse => :monochromatic).usage).to include("[--monochromatic]")
+ end
+
+ it "creates the inversion flag by default" do
+ expect(option("bar", type: :boolean).usage).to include("[--no-bar]")
+ end
+
+ it "creates the inversion flag when requested" do
+ expect(option("bar", type: :boolean, :inverse => true).usage).to include("[--no-bar]")
+ end
+
  describe "with required values" do
  it "does not show the usage between brackets" do
  expect(parse(:foo, :required).usage).to eq("--foo=FOO")