Show hidden

src/CommandLine/UnParserExtensions.cs

@@ -18,6 +18,7 @@ public class UnParserSettings
         private bool preferShortName;
         private bool groupSwitches;
         private bool useEqualToken;
+        private bool showHidden;
 
         /// <summary>
         /// Gets or sets a value indicating whether unparsing process shall prefer short or long names.
@@ -46,6 +47,14 @@ public bool UseEqualToken
             set { PopsicleSetter.Set(Consumed, ref useEqualToken, value); }
         }
 
+        /// <summary>
+        /// Gets or sets a value indicating whether unparsing process shall expose hidden options.
+        /// </summary>
+        public bool ShowHidden
+        {
+            get { return showHidden; }
+            set { PopsicleSetter.Set(Consumed, ref showHidden, value); }
+        }
         /// <summary>
         /// Factory method that creates an instance of <see cref="CommandLine.UnParserSettings"/> with GroupSwitches set to true.
         /// </summary>
@@ -119,6 +128,7 @@ public static string FormatCommandLine<T>(this Parser parser, T options, Action<
             var allOptSpecs = from info in specs.Where(i => i.Specification.Tag == SpecificationType.Option)
                 let o = (OptionSpecification)info.Specification
                 where o.TargetType != TargetType.Switch || (o.TargetType == TargetType.Switch && ((bool)info.Value))
+                where !o.Hidden || settings.ShowHidden
                 orderby o.UniqueName()
                 select info;
 
@@ -206,9 +216,10 @@ private static string FormatOption(OptionSpecification spec, object value, UnPar
 
         private static string FormatName(this OptionSpecification optionSpec, UnParserSettings settings)
         {
-            var longName =
-                optionSpec.LongName.Length > 0
-                && !settings.PreferShortName;
+            // Have a long name and short name not preferred? Go with long! 
+            // No short name? Has to be long!
+            var longName = (optionSpec.LongName.Length >  0 && !settings.PreferShortName)
+                         || optionSpec.ShortName.Length == 0;
 
             return
                 new StringBuilder(longName

tests/CommandLine.Tests/CommandLine.Tests.csproj

@@ -58,6 +58,7 @@
       <Link>Properties\SharedAssemblyInfo.cs</Link>
     </Compile>
     <Compile Include="CultureInfoExtensions.cs" />
+    <Compile Include="Fakes\Hidden_Option.cs" />
     <Compile Include="Fakes\Options_With_Default_Set_To_Sequence.cs" />
     <Compile Include="Fakes\Options_With_Guid.cs" />
     <Compile Include="Fakes\Options_With_Option_And_Value_Of_String_Type.cs" />

tests/CommandLine.Tests/Fakes/Hidden_Option.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace CommandLine.Tests.Fakes
+{
+    public class Hidden_Option
+    {
+        [Option('h', "hiddenOption", Default="hidden", Hidden = true)]
+        public string HiddenOption { get; set; }
+    }
+}

tests/CommandLine.Tests/Unit/UnParserExtensionsTests.cs

@@ -40,6 +40,15 @@ public static void UnParsing_immutable_instance_returns_command_line(Immutable_S
                 .ShouldBeEquivalentTo(result);
         }
 
+        [Theory]
+        [MemberData("UnParseDataHidden")]
+        public static void Unparsing_hidden_option_returns_command_line(Hidden_Option options, bool showHidden, string result)
+        {
+            new Parser()
+                .FormatCommandLine(options, config => config.ShowHidden = showHidden)
+                .ShouldBeEquivalentTo(result);
+        }
+
 #if !SKIP_FSHARP
         [Theory]
         [MemberData("UnParseDataFSharpOption")]
@@ -141,6 +150,14 @@ public static IEnumerable<object> UnParseDataImmutable
             }
         }
 
+        public static IEnumerable<object> UnParseDataHidden
+        {
+            get
+            {
+                yield return new object[] { new Hidden_Option { HiddenOption = "hidden" }, true, "--hiddenOption hidden" };
+                yield return new object[] { new Hidden_Option { HiddenOption = "hidden" }, false, ""};
+            }
+        }
 #if !SKIP_FSHARP
         public static IEnumerable<object> UnParseDataFSharpOption
         {