Added setting to disable implicit short options

lib/optimist.rb

@@ -84,7 +84,11 @@ def self.registry_getopttype(type)
   ##  ignore options that it does not recognize.
   attr_accessor :ignore_invalid_options
 
-  DEFAULT_SETTINGS = { suggestions: true, exact_match: true }
+  DEFAULT_SETTINGS = {
+    exact_match: true,
+    implicit_short_opts: true,
+    suggestions: true
+  }
 
   ## Initializes the parser, and instance-evaluates any block given.
   def initialize(*a, &b)
@@ -313,7 +317,7 @@ def parse(cmdline = ARGV)
       vals[sym] = [] if opts.multi && !opts.default # multi arguments default to [], not nil
     end
 
-    resolve_default_short_options!
+    resolve_default_short_options! if @settings[:implicit_short_opts]
 
     ## resolve symbols
     given_args = {}
@@ -1027,6 +1031,7 @@ def multi_arg? ; true ; end
 ##  +settings+ include:
 ##  * :exact_match  : (default=true) Allow minimum unambigous number of characters to match a long option
 ##  * :suggestions  : (default=true) Enables suggestions when unknown arguments are given and DidYouMean is installed.  DidYouMean comes standard with Ruby 2.3+
+##  * :implicit_short_opts : (default=true) Short options will only be created where explicitly defined.  If you do not like short-options, this will prevent having to define :short=> :none for all of your options.
 ##  Because Optimist::options uses a default argument for +args+, you must pass that argument when using the settings feature.
 ##
 ## See more examples at https://www.manageiq.org/optimist

test/optimist/parser_test.rb

@@ -1177,6 +1177,39 @@ def test_default_shorts_assigned_only_after_user_shorts
     assert opts[:ccd]
   end
 
+  def test_short_opts_not_implicitly_created
+    newp = Parser.new(implicit_short_opts: false)
+    newp.opt :user1, "user1"
+    newp.opt :bag, "bag", :short => 'b'
+    assert_raises(CommandlineError) do
+      newp.parse %w(-u)
+    end
+    opts = newp.parse %w(--user1)
+    assert opts[:user1]
+    opts = newp.parse %w(-b)
+    assert opts[:bag]
+  end
+
+  def test_short_opts_not_implicit_help_ver
+    # When implicit_short_opts is false this implies the short options
+    # for the built-in help/version are also not created.
+    newp = Parser.new(implicit_short_opts: false)
+    newp.opt :abc, "abc"
+    newp.version "3.4.5"
+    assert_raises(CommandlineError) do
+      newp.parse %w(-h)
+    end
+    assert_raises(CommandlineError) do
+      newp.parse %w(-v)
+    end
+    assert_raises(HelpNeeded) do
+      newp.parse %w(--help)
+    end
+    assert_raises(VersionNeeded) do
+      newp.parse %w(--version)
+    end
+  end
+
   def test_inexact_match
     newp = Parser.new(exact_match: false)
     newp.opt :liberation, "liberate something", :type => :int