⚗️ choice group experiment with analyzer

.gitignore

@@ -424,3 +424,4 @@ src/siri/**/Generated/
 # Local xscgen pre-release package (band-aid until upstream merges).
 # Must appear after both the *.nupkg and **/[Pp]ackages/* rules to negate them.
 !**/[Pp]ackages/XmlSchemaClassGenerator-beta.*.nupkg
+!**/[Pp]ackages/XmlSchemaClassGenerator*.nupkg

src/Directory.Packages.props

@@ -8,7 +8,8 @@
     <PackageVersion Include="MinVer" Version="6.0.0" />
 
     <!-- Generator dependencies -->
-    <PackageVersion Include="XmlSchemaClassGenerator-beta" Version="99.0.5-local" />
+    <PackageVersion Include="XmlSchemaClassGenerator-beta" Version="99.0.7-local" />
+    <PackageVersion Include="XmlSchemaClassGenerator.Analyzer" Version="99.0.7-local" />
     <PackageVersion Include="System.CommandLine" Version="2.0.2" />
 
     <!-- Test dependencies -->

src/generator/Spillgebees.Transmodel.Generator/Services/CodeGenerator.cs

@@ -27,7 +27,7 @@ [new NamespaceKey(SharedDefaults.GmlXmlNamespace)] = gmlNamespace,
             [new NamespaceKey(SharedDefaults.W3XmlNamespace)] = w3Namespace
         };
 
-        var generator = CreateBaseGenerator(outputDirectory, namespaceProvider, verbose);
+        var generator = CreateBaseGenerator(outputDirectory, rootNamespace, namespaceProvider, verbose);
         // Set NamingProvider after the object initializer to avoid being overwritten
         // by any NamingScheme setter. This renames abstract dummy elements (e.g. 'StopPlace_')
         // so that concrete elements get the clean C# class name (e.g. 'StopPlace').
@@ -91,7 +91,7 @@ [new NamespaceKey(SharedDefaults.GmlXmlNamespace)] = gmlNamespace,
             [new NamespaceKey(SharedDefaults.W3XmlNamespace)] = w3Namespace
         };
 
-        var generator = CreateBaseGenerator(outputDirectory, namespaceProvider, verbose);
+        var generator = CreateBaseGenerator(outputDirectory, rootNamespace, namespaceProvider, verbose);
         // SIRI doesn't have the underscore naming convention, use default PascalCase
         generator.NamingProvider = new NamingProvider(NamingScheme.PascalCase);
 
@@ -115,6 +115,7 @@ [new NamespaceKey(SharedDefaults.W3XmlNamespace)] = w3Namespace
 
     private static XscGenerator CreateBaseGenerator(
         string outputDirectory,
+        string rootNamespace,
         NamespaceProvider namespaceProvider,
         bool verbose)
     {
@@ -143,10 +144,12 @@ private static XscGenerator CreateBaseGenerator(
             CollectionType = typeof(List<>),
             EnumCollection = true,
 
-            // Nullable and required
+            // Nullable, required, and choice groups
             EnableNullableDirective = true,
             GenerateRequiredModifier = true,
             UseShouldSerializePattern = true,
+            GenerateChoiceGroupAttributes = true,
+            ChoiceGroupAttributeNamespace = rootNamespace,
 
             // Minimal attribute noise
             GenerateSerializableAttribute = false,

src/netex/NeTEx.Models.targets

@@ -18,6 +18,12 @@
     <None Include="../Spillgebees.NeTEx.Models/README.md" Pack="true" PackagePath="" />
   </ItemGroup>
 
+  <ItemGroup>
+    <PackageReference Include="XmlSchemaClassGenerator.Analyzer" PrivateAssets="none">
+      <IncludeAssets>analyzers</IncludeAssets>
+    </PackageReference>
+  </ItemGroup>
+
   <!-- Trigger generator to run before compilation if NetexVersion is set and no generated files exist -->
   <Target Name="GenerateNetexModels"
           Condition="'$(NetexVersion)' != ''"

src/netex/Spillgebees.NeTEx.Models.Tests/ChoiceGroupAttributeTests.cs

@@ -0,0 +1,123 @@
+using System.Reflection;
+using AwesomeAssertions;
+using Spillgebees.NeTEx.Models.V1_3_1;
+using Spillgebees.NeTEx.Models.V1_3_1.NeTEx;
+
+namespace Spillgebees.NeTEx.Models.Tests;
+
+/// <summary>
+/// Tests verifying that the generated NeTEx v1.3.1 models carry correct
+/// <see cref="XmlChoiceGroupAttribute"/> annotations on properties that
+/// originate from <c>xs:choice</c> groups in the NeTEx XSD schemas.
+/// </summary>
+public class ChoiceGroupAttributeTests
+{
+    // -- helpers ------------------------------------------------------------------
+
+    private static XmlChoiceGroupAttribute? GetChoiceGroupAttribute<T>(string propertyName) =>
+        typeof(T).GetProperty(propertyName)?
+            .GetCustomAttribute<XmlChoiceGroupAttribute>();
+
+    private static XmlChoiceGroupAttribute GetRequiredChoiceGroupAttribute<T>(string propertyName)
+    {
+        var attr = GetChoiceGroupAttribute<T>(propertyName);
+        attr.Should().NotBeNull($"property {typeof(T).Name}.{propertyName} should have [XmlChoiceGroupAttribute]");
+        return attr!;
+    }
+
+    // -- DistanceMatrixElementDerivedViewStructure: two parallel choice groups -----
+
+    [Test]
+    public void Should_have_choice_group_on_start_stop_point_ref()
+    {
+        var attr = GetRequiredChoiceGroupAttribute<DistanceMatrixElementDerivedViewStructure>(
+            nameof(DistanceMatrixElementDerivedViewStructure.StartStopPointRef));
+
+        attr.ArmId.Should().Be(0);
+    }
+
+    [Test]
+    public void Should_have_choice_group_on_start_tariff_zone_ref()
+    {
+        var attr = GetRequiredChoiceGroupAttribute<DistanceMatrixElementDerivedViewStructure>(
+            nameof(DistanceMatrixElementDerivedViewStructure.StartTariffZoneRef));
+
+        attr.ArmId.Should().Be(1);
+    }
+
+    [Test]
+    public void Should_have_same_group_id_for_start_choice()
+    {
+        var stopRef = GetRequiredChoiceGroupAttribute<DistanceMatrixElementDerivedViewStructure>(
+            nameof(DistanceMatrixElementDerivedViewStructure.StartStopPointRef));
+        var zoneRef = GetRequiredChoiceGroupAttribute<DistanceMatrixElementDerivedViewStructure>(
+            nameof(DistanceMatrixElementDerivedViewStructure.StartTariffZoneRef));
+
+        stopRef.GroupId.Should().Be(zoneRef.GroupId);
+    }
+
+    [Test]
+    public void Should_have_choice_group_on_end_stop_point_ref()
+    {
+        var attr = GetRequiredChoiceGroupAttribute<DistanceMatrixElementDerivedViewStructure>(
+            nameof(DistanceMatrixElementDerivedViewStructure.EndStopPointRef));
+
+        attr.ArmId.Should().Be(0);
+    }
+
+    [Test]
+    public void Should_have_choice_group_on_end_tariff_zone_ref()
+    {
+        var attr = GetRequiredChoiceGroupAttribute<DistanceMatrixElementDerivedViewStructure>(
+            nameof(DistanceMatrixElementDerivedViewStructure.EndTariffZoneRef));
+
+        attr.ArmId.Should().Be(1);
+    }
+
+    [Test]
+    public void Should_have_same_group_id_for_end_choice()
+    {
+        var stopRef = GetRequiredChoiceGroupAttribute<DistanceMatrixElementDerivedViewStructure>(
+            nameof(DistanceMatrixElementDerivedViewStructure.EndStopPointRef));
+        var zoneRef = GetRequiredChoiceGroupAttribute<DistanceMatrixElementDerivedViewStructure>(
+            nameof(DistanceMatrixElementDerivedViewStructure.EndTariffZoneRef));
+
+        stopRef.GroupId.Should().Be(zoneRef.GroupId);
+    }
+
+    [Test]
+    public void Should_have_different_group_ids_for_start_and_end_choices()
+    {
+        var startAttr = GetRequiredChoiceGroupAttribute<DistanceMatrixElementDerivedViewStructure>(
+            nameof(DistanceMatrixElementDerivedViewStructure.StartStopPointRef));
+        var endAttr = GetRequiredChoiceGroupAttribute<DistanceMatrixElementDerivedViewStructure>(
+            nameof(DistanceMatrixElementDerivedViewStructure.EndStopPointRef));
+
+        startAttr.GroupId.Should().NotBe(endAttr.GroupId);
+    }
+
+    [Test]
+    public void Should_not_have_choice_group_on_non_choice_property()
+    {
+        // StartName is not part of any choice group
+        var attr = GetChoiceGroupAttribute<DistanceMatrixElementDerivedViewStructure>("StartName");
+
+        attr.Should().BeNull();
+    }
+
+    // -- FareStructureElementVersionStructure: multiple choice groups in NeTEx -----
+
+    [Test]
+    public void Should_have_multiple_distinct_choice_groups_on_fare_structure_element()
+    {
+        var properties = typeof(FareStructureElementVersionStructure).GetProperties();
+        var choiceGroupIds = properties
+            .Select(p => p.GetCustomAttribute<XmlChoiceGroupAttribute>())
+            .Where(a => a is not null)
+            .Select(a => a!.GroupId)
+            .Distinct()
+            .ToList();
+
+        choiceGroupIds.Count.Should().BeGreaterThanOrEqualTo(2);
+    }
+}

src/siri/SIRI.Models.targets

@@ -18,6 +18,12 @@
     <None Include="../Spillgebees.SIRI.Models/README.md" Pack="true" PackagePath="" />
   </ItemGroup>
 
+  <ItemGroup>
+    <PackageReference Include="XmlSchemaClassGenerator.Analyzer" PrivateAssets="none">
+      <IncludeAssets>analyzers</IncludeAssets>
+    </PackageReference>
+  </ItemGroup>
+
   <!-- Trigger generator to run before compilation if SiriVersion is set and no generated files exist -->
   <Target Name="GenerateSiriModels"
           Condition="'$(SiriVersion)' != ''"