Enable help as a command/argument (#56)

Author: daningalla

src/Vertical.CommandLine.csproj

@@ -9,7 +9,7 @@
     <PublicSign Condition="'$(OS)' != 'Windows_NT'">true</PublicSign>
     <Description>Simple command line argument mapping</Description>
     <Authors>Vertical Software contributors</Authors>
-    <VersionPrefix>2.1.1</VersionPrefix>
+    <VersionPrefix>2.2.0</VersionPrefix>
     <PackageId>vertical-commandline</PackageId>
     <PackageTags>commandline;utilities</PackageTags>
     <PackageProjectUrl>https://github.com/verticalsoftware/vertical-commandline</PackageProjectUrl>

src/Vertical/CommandLine/Configuration/ApplicationConfiguration.cs

@@ -80,8 +80,7 @@ public ApplicationConfiguration<TOptions> Command<TCommandOptions>(string templa
         /// <returns>Configuration.</returns>
         public ApplicationConfiguration<TOptions> HelpOption(string template, IHelpWriter? helpWriter = null)
         {
-            HelpTemplate = Template.ForOptionOrSwitch(template);
-
+            HelpTemplate = Template.Parse(template);
             _helpWriter = helpWriter;
             ParserConfig.AddTemplate(HelpTemplate);
             ParserConfig.AddParser(new HelpOptionParser<TOptions>(HelpTemplate));

src/Vertical/CommandLine/Parsing/Template.cs

@@ -55,6 +55,18 @@ internal static Template ForCommand(string template)
                 () => ConfigurationExceptions.InvalidCommandTemplate(template)));
         }
 
+        /// <summary>
+        /// Creates either an option, switch, or command template.
+        /// </summary>
+        /// <param name="template">String to convert to template.</param>
+        /// <returns><see cref="Template"/></returns>
+        internal static Template Parse(string template)
+        {
+            return template.StartsWith("-")
+                ? ForOptionOrSwitch(template)
+                : ForCommand(template);
+        }
+
         /// <inheritdoc />
         public override string ToString() => string.Join(TokenSeparator.ToString(),
             Tokens.Select(token => token.DistinguishedForm));

test/Parsing/HelpOptionParserTests.cs

@@ -18,25 +18,36 @@ public class HelpOptionParserTests
         private readonly IArgumentParser<object> _instanceUnderTest = new HelpOptionParser<object>(Template);
 
         [Theory, MemberData(nameof(Theories))]
-        public void ProcessContextReturnsExpected(string arg, ContextResult expected)
+        public void ProcessContextReturnsExpected(string templateString, string arg, ContextResult expected)
         {
+            var instanceUnderTest = new HelpOptionParser<object>(Template.Parse(templateString));
             var context = new ParseContext(new[]{arg});
-            var result = _instanceUnderTest.ProcessContext(null, context);
+            var result = instanceUnderTest.ProcessContext(new object(), context);
 
             result.ShouldBe(expected);
         }
 
         // ReSharper disable once MemberCanBePrivate.Global
         public static IEnumerable<object[]> Theories => Scenarios
         (
-            Scenario("help", ContextResult.NoMatch),
-            Scenario("file.txt", ContextResult.NoMatch),
-            Scenario("-h", ContextResult.Help),
-            Scenario( "--help", ContextResult.Help)
+            Scenario("-h|--help", "help", ContextResult.NoMatch),
+            Scenario("-h|--help", "file.txt", ContextResult.NoMatch),
+            Scenario("-h|--help", "-h", ContextResult.Help),
+            Scenario("-h|--help",  "--help", ContextResult.Help),
+            Scenario("help", "file.txt", ContextResult.NoMatch),
+            Scenario("help",  "help", ContextResult.Help)
         );
 
         [Fact] 
-        public void ParserTypeReturnsHelp() => _instanceUnderTest.ParserType.ShouldBe(ParserType.Help);
+        public void OptionParserTypeReturnsHelp() => new HelpOptionParser<object>(Template.ForOptionOrSwitch("-h|--help")) 
+            .ParserType
+            .ShouldBe(ParserType.Help);
+        
+        
+        [Fact] 
+        public void ArgumentParserTypeReturnsHelp() => new HelpOptionParser<object>(Template.ForCommand("help")) 
+            .ParserType
+            .ShouldBe(ParserType.Help);
 
         [Fact]
         public void ParserMultiValuedReturnsFalse() => _instanceUnderTest.MultiValued.ShouldBe(false);