Allow New-YamlHelp to generate YAML for Common Parameters (#547)

Author: adityapatwardhan

src/Markdown.MAML/Renderer/YamlRenderer.cs

@@ -31,6 +31,17 @@ public static string MamlModelToString(MamlCommand mamlCommand)
                 Syntaxes = mamlCommand.Syntax.Select(CreateSyntax).ToList()
             };
 
+            if (mamlCommand.SupportCommonParameters)
+            {
+                var commonParam = new YamlParameter
+                {
+                    Name = Markdown.MAML.Resources.MarkdownStrings.CommonParametersToken,
+                    Description = Markdown.MAML.Resources.MarkdownStrings.CommonParametersText
+                };
+
+                model.OptionalParameters.Add(commonParam);
+            }
+
             using (var writer = new StringWriter())
             {
                 serializer.Serialize(writer, model);

test/Markdown.MAML.Test/Renderer/YamlRendererTests.cs

@@ -119,9 +119,9 @@ public void RenderProducesOptionalParameters()
 
             var writtenModel = deserializer.Deserialize<YamlCommand>(output);
 
-            Assert.Single(writtenModel.OptionalParameters);
+            Assert.Equal(2, writtenModel.OptionalParameters.Count);
 
-            var optionalParameter = writtenModel.OptionalParameters.Single();
+            var optionalParameter = writtenModel.OptionalParameters.First();
             var expectedParameter = model.Parameters.Single(p => !p.Required);
 
             Assert.Equal(expectedParameter.Globbing, optionalParameter.AcceptWildcardCharacters);
@@ -197,7 +197,7 @@ public void RenderProducesSyntaxes()
             var syntax = writtenModel.Syntaxes.Single();
 
             Assert.Equal(model.Syntax.Single().ParameterSetName, syntax.ParameterValueGroup);
-            
+
             Assert.Single(syntax.Parameters);
             Assert.Equal(model.Syntax.Single().Parameters.Single().Name, syntax.Parameters.Single());
         }

test/Pester/PlatyPs.Tests.ps1

@@ -1621,7 +1621,7 @@ Describe 'New-YamlHelp' {
         $yamlModel.RequiredParameters[0].Name | Should Be 'Path'
         $yamlModel.RequiredParameters[1].Name | Should Be 'OutputFolder'
 
-        $yamlModel.OptionalParameters.Count | Should Be 2
+        $yamlModel.OptionalParameters.Count | Should Be 3
 
         $yamlModel.OptionalParameters[0].Name | Should Be 'Encoding'
         $yamlModel.OptionalParameters[1].Name | Should Be 'Force'