From 6e7742a4f302265d08c7d66a4462344d9c8ea479 Mon Sep 17 00:00:00 2001
From: Alexey Golub <tyrrrz@gmail.com>
Date: Fri, 8 May 2020 16:40:19 +0300
Subject: [PATCH] Show valid values for parameters too

---
 CliFx.Tests/HelpTextSpecs.Commands.cs | 13 ++++++++-----
 CliFx.Tests/HelpTextSpecs.cs          | 10 ++++++----
 CliFx/Domain/HelpTextWriter.cs        | 11 +++++++++++
 3 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/CliFx.Tests/HelpTextSpecs.Commands.cs b/CliFx.Tests/HelpTextSpecs.Commands.cs
index 620dff0..bd0bdd9 100644
--- a/CliFx.Tests/HelpTextSpecs.Commands.cs
+++ b/CliFx.Tests/HelpTextSpecs.Commands.cs
@@ -82,16 +82,19 @@ namespace CliFx.Tests
             public ValueTask ExecuteAsync(IConsole console) => default;
         }
 
-        [Command("cmd-with-enum-opts")]
-        private class EnumOptionsCommand : ICommand
+        [Command("cmd-with-enum-args")]
+        private class EnumArgumentsCommand : ICommand
         {
-            public enum ValuesEnum { Value1, Value2, Value3 };
+            public enum TestEnum { Value1, Value2, Value3 };
+
+            [CommandParameter(0, Name = "value", Description = "Enum parameter.")]
+            public TestEnum ParamA { get; set; }
 
             [CommandOption("value", Description = "Enum option.", IsRequired = true)]
-            public ValuesEnum Value { get; set; } = ValuesEnum.Value1;
+            public TestEnum OptionA { get; set; } = TestEnum.Value1;
 
             [CommandOption("nullable-value", Description = "Nullable enum option.")]
-            public ValuesEnum? NullableValue { get; set; }
+            public TestEnum? OptionB { get; set; }
 
             public ValueTask ExecuteAsync(IConsole console) => default;
         }
diff --git a/CliFx.Tests/HelpTextSpecs.cs b/CliFx.Tests/HelpTextSpecs.cs
index d0e17db..714bdb5 100644
--- a/CliFx.Tests/HelpTextSpecs.cs
+++ b/CliFx.Tests/HelpTextSpecs.cs
@@ -239,25 +239,27 @@ namespace CliFx.Tests
         }
 
         [Fact]
-        public async Task Help_text_shows_usage_format_which_lists_all_valid_values_for_enum_options()
+        public async Task Help_text_shows_usage_format_which_lists_all_valid_values_for_enum_arguments()
         {
             // Arrange
             await using var stdOut = new MemoryStream();
             var console = new VirtualConsole(output: stdOut);
 
             var application = new CliApplicationBuilder()
-                .AddCommand(typeof(EnumOptionsCommand))
+                .AddCommand(typeof(EnumArgumentsCommand))
                 .UseConsole(console)
                 .Build();
 
             // Act
-            await application.RunAsync(new[] { "cmd-with-enum-opts", "--help" });
+            await application.RunAsync(new[] { "cmd-with-enum-args", "--help" });
             var stdOutData = console.Output.Encoding.GetString(stdOut.ToArray()).TrimEnd();
 
             // Assert
             stdOutData.Should().ContainAll(
                 "Usage",
-                "cmd-with-enum-opts", "[options]",
+                "cmd-with-enum-args", "[options]",
+                "Parameters",
+                "value", "Valid values: Value1, Value2, Value3.",
                 "Options",
                 "* --value", "Enum option.", "Valid values: Value1, Value2, Value3.",
                 "--nullable-value", "Nullable enum option.", "Valid values: Value1, Value2, Value3."
diff --git a/CliFx/Domain/HelpTextWriter.cs b/CliFx/Domain/HelpTextWriter.cs
index 3be9f95..b50e6eb 100644
--- a/CliFx/Domain/HelpTextWriter.cs
+++ b/CliFx/Domain/HelpTextWriter.cs
@@ -199,6 +199,15 @@ namespace CliFx.Domain
                     if (!string.IsNullOrWhiteSpace(parameter.Description))
                     {
                         Render(parameter.Description);
+                        Render(" ");
+                    }
+
+                    // Valid values
+                    var validValues = parameter.GetValidValues();
+                    if (validValues.Any())
+                    {
+                        Render($"Valid values: {string.Join(", ", validValues)}.");
+                        Render(" ");
                     }
 
                     RenderNewLine();
@@ -246,12 +255,14 @@ namespace CliFx.Domain
 
                     RenderColumnIndent();
 
+                    // Description
                     if (!string.IsNullOrWhiteSpace(option.Description))
                     {
                         Render(option.Description);
                         Render(" ");
                     }
 
+                    // Valid values
                     var validValues = option.GetValidValues();
                     if (validValues.Any())
                     {