Make attribute resolution extensible via dependency injection.

TerraformPluginDotNet.Test/ResourceProvider/ResourceRegistryTest.cs

@@ -2,6 +2,7 @@
 using NUnit.Framework;
 using TerraformPluginDotNet.ResourceProvider;
 using TerraformPluginDotNet.Schemas;
+using TerraformPluginDotNet.Schemas.Attributes;
 using TerraformPluginDotNet.Schemas.Types;
 using Tfplugin5;
 
@@ -38,7 +39,7 @@ private static ResourceRegistry BuildRegistry()
     {
         var registration = new ResourceRegistryRegistration("test_resource", typeof(TestResource));
         var dataSourceRegistration = new DataSourceRegistryRegistration("test_data_source", typeof(TestResource));
-        var registry = new ResourceRegistry(new SchemaBuilder(NullLogger<SchemaBuilder>.Instance, new TerraformTypeBuilder()), new[] { registration }, new[] { dataSourceRegistration });
+        var registry = new ResourceRegistry(new SchemaBuilder(NullLogger<SchemaBuilder>.Instance, new TerraformTypeBuilder(), new TerraformAttributeResolver()), new[] { registration }, new[] { dataSourceRegistration });
         return registry;
     }
 }

TerraformPluginDotNet.Test/Schemas/SchemaBuilderTest.cs

@@ -2,6 +2,7 @@
 using Microsoft.Extensions.Logging.Abstractions;
 using NUnit.Framework;
 using TerraformPluginDotNet.Schemas;
+using TerraformPluginDotNet.Schemas.Attributes;
 using TerraformPluginDotNet.Schemas.Types;
 
 namespace TerraformPluginDotNet.Test.Schemas;
@@ -16,7 +17,8 @@ public void Setup()
     {
         _schemaBuilder = new SchemaBuilder(
             NullLogger<SchemaBuilder>.Instance,
-            new TerraformTypeBuilder());
+            new TerraformTypeBuilder(),
+            new TerraformAttributeResolver());
     }
 
     [Test]

TerraformPluginDotNet/Schemas/Attributes/ITerraformAttributeResolver.cs

@@ -0,0 +1,16 @@
+using System.Reflection;
+
+namespace TerraformPluginDotNet.Schemas.Attributes;
+
+public interface ITerraformAttributeResolver
+{
+    string GetKey(PropertyInfo property);
+
+    string? GetDescription(PropertyInfo property);
+
+    bool IsRequired(PropertyInfo property);
+
+    bool IsComputed(PropertyInfo property);
+
+    bool? IsOptional(PropertyInfo property);
+}

TerraformPluginDotNet/Schemas/Attributes/TerraformAttributeResolver.cs

@@ -0,0 +1,35 @@
+using System.ComponentModel;
+using System.Reflection;
+using MessagePack;
+using TerraformPluginDotNet.Resources;
+using TerraformPluginDotNet.Schemas.Types;
+
+namespace TerraformPluginDotNet.Schemas.Attributes;
+
+public class TerraformAttributeResolver : ITerraformAttributeResolver
+{
+    public string? GetDescription(PropertyInfo property)
+    {
+        return property.GetCustomAttribute<DescriptionAttribute>()?.Description;
+    }
+
+    public string GetKey(PropertyInfo property)
+    {
+        return property.GetCustomAttribute<KeyAttribute>()?.StringKey ?? throw new InvalidOperationException($"Missing {nameof(KeyAttribute)} on {property.Name} in {property.DeclaringType?.Name}.");
+    }
+
+    public bool IsComputed(PropertyInfo property)
+    {
+        return property.GetCustomAttribute<ComputedAttribute>() is not null;
+    }
+
+    public bool? IsOptional(PropertyInfo property)
+    {
+        return null;
+    }
+
+    public bool IsRequired(PropertyInfo property)
+    {
+        return TerraformTypeBuilder.IsRequiredAttribute(property);
+    }
+}

TerraformPluginDotNet/Schemas/SchemaBuilder.cs

@@ -3,21 +3,24 @@
 using Google.Protobuf;
 using Microsoft.Extensions.Logging;
 using TerraformPluginDotNet.Resources;
+using TerraformPluginDotNet.Schemas.Attributes;
 using TerraformPluginDotNet.Schemas.Types;
 using Tfplugin5;
 using KeyAttribute = MessagePack.KeyAttribute;
 
 namespace TerraformPluginDotNet.Schemas;
 
-class SchemaBuilder : ISchemaBuilder
+public class SchemaBuilder : ISchemaBuilder
 {
     private readonly ILogger<SchemaBuilder> _logger;
     private readonly ITerraformTypeBuilder _typeBuilder;
+    private readonly ITerraformAttributeResolver _attributeResolver;
 
-    public SchemaBuilder(ILogger<SchemaBuilder> logger, ITerraformTypeBuilder typeBuilder)
+    public SchemaBuilder(ILogger<SchemaBuilder> logger, ITerraformTypeBuilder typeBuilder, ITerraformAttributeResolver attributeResolver)
     {
         _logger = logger;
         _typeBuilder = typeBuilder;
+        _attributeResolver = attributeResolver;
     }
 
     public Schema BuildSchema(Type type)
@@ -33,11 +36,12 @@ public Schema BuildSchema(Type type)
         var block = new Schema.Types.Block();
         foreach (var property in properties)
         {
-            var key = property.GetCustomAttribute<KeyAttribute>() ?? throw new InvalidOperationException($"Missing {nameof(KeyAttribute)} on {property.Name} in {type.Name}.");
+            var key = _attributeResolver.GetKey(property);
 
-            var description = property.GetCustomAttribute<DescriptionAttribute>();
-            var required = TerraformTypeBuilder.IsRequiredAttribute(property);
-            var computed = property.GetCustomAttribute<ComputedAttribute>() != null;
+            var description = _attributeResolver.GetDescription(property);
+            var required = _attributeResolver.IsRequired(property);
+            var computed = _attributeResolver.IsComputed(property);
+            var optional = _attributeResolver.IsOptional(property) ?? !required;
             var terraformType = _typeBuilder.GetTerraformType(property.PropertyType);
 
             if (terraformType is TerraformType.TfObject _ && !required)
@@ -47,12 +51,12 @@ public Schema BuildSchema(Type type)
 
             block.Attributes.Add(new Schema.Types.Attribute
             {
-                Name = key.StringKey,
+                Name = key,
                 Type = ByteString.CopyFromUtf8(terraformType.ToJson()),
-                Description = description?.Description,
-                Optional = !required,
+                Description = description,
                 Required = required,
                 Computed = computed,
+                Optional = optional,
             });
         }
 

TerraformPluginDotNet/ServiceCollectionExtensions.cs

@@ -2,6 +2,7 @@
 using TerraformPluginDotNet.ProviderConfig;
 using TerraformPluginDotNet.ResourceProvider;
 using TerraformPluginDotNet.Schemas;
+using TerraformPluginDotNet.Schemas.Attributes;
 using TerraformPluginDotNet.Schemas.Types;
 using TerraformPluginDotNet.Serialization;
 
@@ -15,6 +16,7 @@ public static class ServiceCollectionExtensions
 {
     public static IServiceCollection AddTerraformPluginCore(this IServiceCollection services)
     {
+        services.AddTransient<ITerraformAttributeResolver, TerraformAttributeResolver>();
         services.AddTransient<ITerraformTypeBuilder, TerraformTypeBuilder>();
         services.AddTransient<ISchemaBuilder, SchemaBuilder>();
         services.AddTransient(typeof(ProviderConfigurationHost<>));