AutoVersion and AutoHelp are removed from HelpText, if not enabled in ParserSettings

src/CommandLine/Parser.cs

@@ -201,16 +201,18 @@ private static ParserResult<T> MakeParserResult<T>(ParserResult<T> parserResult,
         {
             return DisplayHelp(
                 parserResult,
+                settings.AutoVersion,
+                settings.AutoHelp,
                 settings.HelpWriter,
                 settings.MaximumDisplayWidth);
         }
 
-        private static ParserResult<T> DisplayHelp<T>(ParserResult<T> parserResult, TextWriter helpWriter, int maxDisplayWidth)
+        private static ParserResult<T> DisplayHelp<T>(ParserResult<T> parserResult, bool autoVersion, bool autoHelp, TextWriter helpWriter, int maxDisplayWidth)
         {
             parserResult.WithNotParsed(
                 errors =>
                     Maybe.Merge(errors.ToMaybe(), helpWriter.ToMaybe())
-                        .Do((_, writer) => writer.Write(HelpText.AutoBuild(parserResult, maxDisplayWidth)))
+                        .Do((_, writer) => writer.Write(HelpText.AutoBuild(parserResult, maxDisplayWidth, autoVersion, autoHelp)))
                 );
 
             return parserResult;

src/CommandLine/Text/HelpText.cs

@@ -314,6 +314,8 @@ public SentenceBuilder SentenceBuilder
         /// <param name='parserResult'>The <see cref="CommandLine.ParserResult{T}"/> containing the instance that collected command line arguments parsed with <see cref="CommandLine.Parser"/> class.</param>
         /// <param name='onError'>A delegate used to customize the text block of reporting parsing errors text block.</param>
         /// <param name='onExample'>A delegate used to customize <see cref="CommandLine.Text.Example"/> model used to render text block of usage examples.</param>
+        /// <param name='autoVersion'>A value to indicate whether <see cref="HelpText.AutoVersion" /> shall be set or not.</param>
+        /// <param name='autoHelp'>A value to indicate whether <see cref="HelpText.AutoHelp" /> shall be set or not.</param>
         /// <param name="verbsIndex">If true the output style is consistent with verb commands (no dashes), otherwise it outputs options.</param>
         /// <param name="maxDisplayWidth">The maximum width of the display.</param>
         /// <remarks>The parameter <paramref name="verbsIndex"/> is not ontly a metter of formatting, it controls whether to handle verbs or options.</remarks>
@@ -322,15 +324,19 @@ public SentenceBuilder SentenceBuilder
             Func<HelpText, HelpText> onError,
             Func<Example, Example> onExample,
             bool verbsIndex = false,
-            int maxDisplayWidth = DefaultMaximumLength)
+            int maxDisplayWidth = DefaultMaximumLength,
+            bool autoVersion = true,
+            bool autoHelp = true)
         {
             var auto = new HelpText
             {
                 Heading = HeadingInfo.Empty,
                 Copyright = CopyrightInfo.Empty,
                 AdditionalNewLineAfterOption = true,
                 AddDashesToOption = !verbsIndex,
-                MaximumDisplayWidth = maxDisplayWidth
+                MaximumDisplayWidth = maxDisplayWidth,
+                AutoVersion = autoVersion,
+                AutoHelp = autoHelp,
             };
 
             try
@@ -394,14 +400,16 @@ public SentenceBuilder SentenceBuilder
         /// </summary>
         /// <param name='parserResult'>The <see cref="CommandLine.ParserResult{T}"/> containing the instance that collected command line arguments parsed with <see cref="CommandLine.Parser"/> class.</param>
         /// <param name="maxDisplayWidth">The maximum width of the display.</param>
+        /// <param name='autoVersion'>A value to indicate whether <see cref="HelpText.AutoVersion" /> shall be set or not.</param>
+        /// <param name='autoHelp'>A value to indicate whether <see cref="HelpText.AutoHelp" /> shall be set or not.</param>
         /// <returns>
         /// An instance of <see cref="CommandLine.Text.HelpText"/> class.
         /// </returns>
         /// <remarks>This feature is meant to be invoked automatically by the parser, setting the HelpWriter property
         /// of <see cref="CommandLine.ParserSettings"/>.</remarks>
-        public static HelpText AutoBuild<T>(ParserResult<T> parserResult, int maxDisplayWidth = DefaultMaximumLength)
+        public static HelpText AutoBuild<T>(ParserResult<T> parserResult, int maxDisplayWidth = DefaultMaximumLength, bool autoVersion = true, bool autoHelp = true)
         {
-            return AutoBuild<T>(parserResult, h => h, maxDisplayWidth);
+            return AutoBuild<T>(parserResult, h => h, maxDisplayWidth, autoVersion, autoHelp);
         }
 
         /// <summary>
@@ -411,12 +419,14 @@ public static HelpText AutoBuild<T>(ParserResult<T> parserResult, int maxDisplay
         /// <param name='parserResult'>The <see cref="CommandLine.ParserResult{T}"/> containing the instance that collected command line arguments parsed with <see cref="CommandLine.Parser"/> class.</param>
         ///  <param name='onError'>A delegate used to customize the text block of reporting parsing errors text block.</param>
         /// <param name="maxDisplayWidth">The maximum width of the display.</param>
+        /// <param name="autoVersion">A value to indicate whether <see cref="HelpText.AutoVersion" /> shall be set or not.</param>
+        /// <param name="autoHelp">A value to indicate whether <see cref="HelpText.AutoHelp" /> shall be set or not.</param>
         /// <returns>
         /// An instance of <see cref="CommandLine.Text.HelpText"/> class.
         /// </returns>
         /// <remarks>This feature is meant to be invoked automatically by the parser, setting the HelpWriter property
         /// of <see cref="CommandLine.ParserSettings"/>.</remarks>
-        public static HelpText AutoBuild<T>(ParserResult<T> parserResult, Func<HelpText, HelpText> onError, int maxDisplayWidth = DefaultMaximumLength)
+        public static HelpText AutoBuild<T>(ParserResult<T> parserResult, Func<HelpText, HelpText> onError, int maxDisplayWidth = DefaultMaximumLength, bool autoVersion = true, bool autoHelp = true)
         {
             if (parserResult.Tag != ParserResultType.NotParsed)
                 throw new ArgumentException("Excepting NotParsed<T> type.", "parserResult");
@@ -431,7 +441,7 @@ public static HelpText AutoBuild<T>(ParserResult<T> parserResult, Func<HelpText,
                 {
                     onError?.Invoke(current);
                     return DefaultParsingErrorsHandler(parserResult, current);
-                }, e => e, maxDisplayWidth: maxDisplayWidth);
+                }, e => e, maxDisplayWidth: maxDisplayWidth, autoVersion: autoVersion, autoHelp: autoHelp);
 
             var err = errors.OfType<HelpVerbRequestedError>().Single();
             var pr = new NotParsed<object>(TypeInfo.Create(err.Type), new Error[] { err });
@@ -440,12 +450,12 @@ public static HelpText AutoBuild<T>(ParserResult<T> parserResult, Func<HelpText,
                 {
                     onError?.Invoke(current);
                     return DefaultParsingErrorsHandler(pr, current);
-                }, e => e, maxDisplayWidth: maxDisplayWidth)
+                }, e => e, maxDisplayWidth: maxDisplayWidth, autoVersion: autoVersion, autoHelp: autoHelp)
                 : AutoBuild(parserResult, current =>
                 {
                     onError?.Invoke(current);
                     return DefaultParsingErrorsHandler(parserResult, current);
-                }, e => e, true, maxDisplayWidth);
+                }, e => e, true, maxDisplayWidth, autoVersion: autoVersion, autoHelp: autoHelp);
         }
 
         /// <summary>

tests/CommandLine.Tests/Unit/Issue821Tests.cs

@@ -0,0 +1,123 @@
+using System;
+using System.IO;
+using System.Linq;
+using System.Runtime.Serialization.Formatters;
+using System.Text;
+using CommandLine.Tests.Fakes;
+using CommandLine.Text;
+using FluentAssertions;
+using Xunit;
+using Xunit.Abstractions;
+
+//Issue #591
+//When options class is only having explicit interface declarations, it should be detected as mutable.
+
+namespace CommandLine.Tests.Unit
+{
+    public class Issue821Tests
+    {
+        [Verb("do")]
+        private class EmptyDoOptions{
+        };
+
+        [Verb("nothing")]
+        private class EmptyNothingOptions{
+        };
+
+        [Fact]
+        public void not_parsed_should_produce_version_if_set_to_true()
+        {
+            StringBuilder output = new StringBuilder();
+            ParserResult<object> result;
+            using (StringWriter writer = new StringWriter(output))
+            {
+                void ConfigureParser(ParserSettings settings)
+                {
+                    settings.HelpWriter = writer;
+                    settings.AutoVersion = true;
+                }
+
+                using (Parser parser = new Parser(ConfigureParser))                
+                {
+                    result = parser.ParseArguments<EmptyDoOptions, EmptyNothingOptions>(Array.Empty<string>());
+                }
+            }
+
+            result.Should().BeOfType<NotParsed<object>>();
+            string outputContent = output.ToString();
+            outputContent.Should().Contain("version", "Version is set to true and must be contained");
+        }
+
+        [Fact]
+        public void not_parsed_should_not_produce_version_if_set_to_false()
+        {
+            StringBuilder output = new StringBuilder();
+            ParserResult<object> result;
+            using (StringWriter writer = new StringWriter(output))
+            {
+                void ConfigureParser(ParserSettings settings)
+                {
+                    settings.HelpWriter = writer;
+                    settings.AutoVersion = false;
+                }
+
+                using (Parser parser = new Parser(ConfigureParser))                
+                {
+                    result = parser.ParseArguments<EmptyDoOptions, EmptyNothingOptions>(Array.Empty<string>());
+                }
+            }
+
+            result.Should().BeOfType<NotParsed<object>>();
+            string outputContent = output.ToString();
+            outputContent.Should().NotContain("version", "Version is set to false and must not be contained");
+        }
+
+        [Fact]
+        public void not_parsed_should_produce_help_if_set_to_true()
+        {
+            StringBuilder output = new StringBuilder();
+            ParserResult<object> result;
+            using (StringWriter writer = new StringWriter(output))
+            {
+                void ConfigureParser(ParserSettings settings)
+                {
+                    settings.HelpWriter = writer;
+                    settings.AutoHelp = true;
+                }
+
+                using (Parser parser = new Parser(ConfigureParser))                
+                {
+                    result = parser.ParseArguments<EmptyDoOptions, EmptyNothingOptions>(Array.Empty<string>());
+                }
+            }
+
+            result.Should().BeOfType<NotParsed<object>>();
+            string outputContent = output.ToString();
+            outputContent.Should().Contain("help", "Help is set to true and must be contained");
+        }
+
+        [Fact]
+        public void not_parsed_should_not_produce_help_if_set_to_false()
+        {
+            StringBuilder output = new StringBuilder();
+            ParserResult<object> result;
+            using (StringWriter writer = new StringWriter(output))
+            {
+                void ConfigureParser(ParserSettings settings)
+                {
+                    settings.HelpWriter = writer;
+                    settings.AutoHelp = false;
+                }
+
+                using (Parser parser = new Parser(ConfigureParser))                
+                {
+                    result = parser.ParseArguments<EmptyDoOptions, EmptyNothingOptions>(Array.Empty<string>());
+                }
+            }
+
+            result.Should().BeOfType<NotParsed<object>>();
+            string outputContent = output.ToString();
+            outputContent.Should().NotContain("help", "Help is set to false and must not be contained");
+        }
+    }
+}