Added the ability to hide CommandOptions. (#642)

CommandOptions now has an IsHidden property that, when set to true, will cause the option to be hidden from the following cases:

- Help text using `-h|--help`
- Xml representations generated with the `cli xml` command
- Diagnostics displayed with the `cli explain` command

Hidden options can still be outputted with `cli explain` using the `--hidden` option that is also used to display hidden commands.

Fixes #631

test/Spectre.Console.Tests/Unit/Cli/Annotations/CommandOptionAttributeTests.cs

@@ -193,5 +193,25 @@ namespace Spectre.Console.Tests.Unit.Cli.Annotations
             result.ShortNames.ShouldContain("f");
             result.ValueName.ShouldBe("BAR");
         }
+
+        [Fact]
+        public void Is_Not_Hidden_From_Help_By_Default()
+        {
+            // Given, When
+            var result = new CommandOptionAttribute("--foo");
+
+            // Then
+            result.IsHidden.ShouldBeFalse();
+        }
+
+        [Fact]
+        public void Can_Indicate_That_It_Must_Be_Hidden_From_Help_Text()
+        {
+            // Given, When
+            var result = new CommandOptionAttribute("--foo") { IsHidden = true };
+
+            // Then
+            result.IsHidden.ShouldBeTrue();
+        }
     }
 }

test/Spectre.Console.Tests/Unit/Cli/CommandAppTests.Help.cs

@@ -278,6 +278,25 @@ namespace Spectre.Console.Tests.Unit.Cli
                 // Then
                 return Verifier.Verify(result.Output);
             }
+
+            [Fact]
+            [Expectation("Hidden_Command_Options")]
+            public Task Should_Not_Show_Hidden_Command_Options()
+            {
+                // Given
+                var fixture = new CommandAppTester();
+                fixture.SetDefaultCommand<GenericCommand<HiddenOptionSettings>>();
+                fixture.Configure(configurator =>
+                {
+                    configurator.SetApplicationName("myapp");
+                });
+
+                // When
+                var result = fixture.Run("--help");
+
+                // Then
+                return Verifier.Verify(result.Output);
+            }
         }
     }
 }

test/Spectre.Console.Tests/Unit/Cli/CommandAppTests.Xml.cs

@@ -137,6 +137,21 @@ namespace Spectre.Console.Tests.Unit.Cli
                 // Then
                 return Verifier.Verify(result.Output);
             }
+
+            [Fact]
+            [Expectation("Hidden_Command_Options")]
+            public Task Should_Not_Dump_Hidden_Options_On_A_Command()
+            {
+                // Given
+                var fixture = new CommandAppTester();
+                fixture.SetDefaultCommand<HiddenOptionsCommand>();
+
+                // When
+                var result = fixture.Run(Constants.XmlDocCommand);
+
+                // Then
+                return Verifier.Verify(result.Output);
+            }
         }
     }
 }