Fix

Author: reakaleek

src/Elastic.Markdown/Myst/FrontMatter/Products.cs

@@ -321,24 +321,13 @@ public object ReadYaml(IParser parser, Type type, ObjectDeserializer rootDeseria
 				return enumMemberAttr?.Value?.Equals(value.Value, StringComparison.OrdinalIgnoreCase) ?? false;
 			});
 
-		if (product != default)
+		if (Enum.IsDefined(product) && product.GetEnumMemberValue()?.Equals(value.Value) == true)
 			return product;
 
 		throw new InvalidProductException(value.Value);
 	}
 
-	public void WriteYaml(IEmitter emitter, object? value, Type type, ObjectSerializer serializer)
-	{
-		if (value == null)
-			return;
-		var product = (Product)value;
-		var enumMemberAttr = typeof(Product)
-			.GetField(product.ToString())
-			?.GetCustomAttributes(typeof(EnumMemberAttribute), false)
-			.FirstOrDefault() as EnumMemberAttribute;
-
-		emitter.Emit(new Scalar(enumMemberAttr?.Value ?? product.ToString().ToLowerInvariant()));
-	}
+	public void WriteYaml(IEmitter emitter, object? value, Type type, ObjectSerializer serializer) => throw new NotImplementedException();
 }
 
 public class InvalidProductException(string invalidValue)
@@ -356,6 +345,15 @@ public static string GetProductDisplayName(this Product product)
 		return displayAttr?.Name ?? product.ToString();
 	}
 
+	public static string? GetEnumMemberValue(this Product product)
+	{
+		var enumMemberAttr = typeof(Product)
+			.GetField(product.ToString())
+			?.GetCustomAttributes(typeof(EnumMemberAttribute), false)
+			.FirstOrDefault() as EnumMemberAttribute;
+		return enumMemberAttr?.Value;
+	}
+
 
 	private static List<string> GetEnumMemberValues() => Enum.GetValues<Product>()
 		.Select(p =>

tests/Elastic.Markdown.Tests/FrontMatter/YamlFrontMatterTests.cs

@@ -2,6 +2,7 @@
 // Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
 // See the LICENSE file in the project root for more information
 
+using Elastic.Markdown.Myst.FrontMatter;
 using Elastic.Markdown.Tests.Directives;
 using FluentAssertions;
 
@@ -63,3 +64,81 @@ public class NavigationTitleSupportReplacements(ITestOutputHelper output) : Dire
 	[Fact]
 	public void ReadsNavigationTitle() => File.NavigationTitle.Should().Be("Documentation Guide: value");
 }
+
+public class Products(ITestOutputHelper output) : DirectiveTest(output,
+	"""
+	---
+	products:
+	  - "apm"
+	---
+
+	# APM
+	"""
+)
+{
+	[Fact]
+	public void ReadsProducts()
+	{
+		File.YamlFrontMatter.Should().NotBeNull();
+		File.YamlFrontMatter!.Products.Should().NotBeNull()
+			.And.HaveCount(1)
+			.And.Contain(Product.Apm);
+	}
+}
+
+public class ProductsSuggestionWhenMispelled(ITestOutputHelper output) : DirectiveTest(output,
+	"""
+	---
+	products:
+	  - aapm
+	---
+
+	# APM
+	"""
+)
+{
+	[Fact]
+	public void HasErrors()
+	{
+		Collector.Diagnostics.Should().HaveCount(1);
+		Collector.Diagnostics.Should().Contain(d => d.Message.Contains("Invalid products frontmatter value: \"aapm\". Did you mean \"apm\"?"));
+	}
+}
+
+public class ProductsSuggestionWhenMispelled2(ITestOutputHelper output) : DirectiveTest(output,
+	"""
+	---
+	products:
+	  - apm-javaagent
+	---
+
+	# APM
+	"""
+)
+{
+	[Fact]
+	public void HasErrors()
+	{
+		Collector.Diagnostics.Should().HaveCount(1);
+		Collector.Diagnostics.Should().Contain(d => d.Message.Contains("Invalid products frontmatter value: \"apm-javaagent\". Did you mean \"apm-java-agent\"?"));
+	}
+}
+
+public class ProductsSuggestionWhenCasingError(ITestOutputHelper output) : DirectiveTest(output,
+	"""
+	---
+	products:
+	  - Apm
+	---
+
+	# APM
+	"""
+)
+{
+	[Fact]
+	public void HasErrors()
+	{
+		Collector.Diagnostics.Should().HaveCount(1);
+		Collector.Diagnostics.Should().Contain(d => d.Message.Contains("Invalid products frontmatter value: \"Apm\". Did you mean \"apm\"?"));
+	}
+}