chore: various fixes for PR review, mostly style and variable naming

Author: maurei

src/JsonApiDotNetCore/Internal/Contracts/IResourceGraph.cs

@@ -0,0 +1,61 @@
+using System;
+using System.Collections.Generic;
+using System.Linq.Expressions;
+using JsonApiDotNetCore.Models;
+
+namespace JsonApiDotNetCore.Internal.Contracts
+{
+    /// <summary>
+    /// Responsible for retrieving the exposed resource fields (attributes and
+    /// relationships) of registered resources in the resource graph.
+    /// </summary>
+    public interface IResourceGraphExplorer : IContextEntityProvider
+    {
+        /// <summary>
+        /// Gets all fields (attributes and relationships) for <typeparamref name="TResource"/>
+        /// that are targeted by the selector. If no selector is provided, all
+        /// exposed fields are returned.
+        /// </summary>
+        /// <typeparam name="TResource">The resource for which to retrieve fields</typeparam>
+        /// <param name="selector">Should be of the form: (TResource e) => new { e.Field1, e.Field2 }</param>
+        List<IResourceField> GetFields<TResource>(Expression<Func<TResource, dynamic>> selector = null) where TResource : IIdentifiable;
+        /// <summary>
+        /// Gets all attributes for <typeparamref name="TResource"/>
+        /// that are targeted by the selector. If no selector is provided, all
+        /// exposed fields are returned.
+        /// </summary>
+        /// <typeparam name="TResource">The resource for which to retrieve attributes</typeparam>
+        /// <param name="selector">Should be of the form: (TResource e) => new { e.Attribute1, e.Arttribute2 }</param>
+        List<AttrAttribute> GetAttributes<TResource>(Expression<Func<TResource, dynamic>> selector = null) where TResource : IIdentifiable;
+        /// <summary>
+        /// Gets all relationships for <typeparamref name="TResource"/>
+        /// that are targeted by the selector. If no selector is provided, all
+        /// exposed fields are returned.
+        /// </summary>
+        /// <typeparam name="TResource">The resource for which to retrieve relationships</typeparam>
+        /// <param name="selector">Should be of the form: (TResource e) => new { e.Relationship1, e.Relationship2 }</param>
+        List<RelationshipAttribute> GetRelationships<TResource>(Expression<Func<TResource, dynamic>> selector = null) where TResource : IIdentifiable;
+        /// <summary>
+        /// Gets all exposed fields (attributes and relationships) for type <paramref name="type"/>
+        /// </summary>
+        /// <param name="type">The resource type. Must extend IIdentifiable.</param>
+        List<IResourceField> GetFields(Type type);
+        /// <summary>
+        /// Gets all exposed attributes for type <paramref name="type"/>
+        /// </summary>
+        /// <param name="type">The resource type. Must extend IIdentifiable.</param>
+        List<AttrAttribute> GetAttributes(Type type);
+        /// <summary>
+        /// Gets all exposed relationships for type <paramref name="type"/>
+        /// </summary>
+        /// <param name="type">The resource type. Must extend IIdentifiable.</param>
+        List<RelationshipAttribute> GetRelationships(Type type);
+
+        /// <summary>
+        /// Traverses the resource graph for the inverse relationship of the provided
+        /// <paramref name="relationship"/>;
+        /// </summary>
+        /// <param name="relationship"></param>
+        RelationshipAttribute GetInverse(RelationshipAttribute relationship);
+    }
+}

src/JsonApiDotNetCore/Internal/Contracts/IResourceGraphExplorer.cs

@@ -0,0 +1,11 @@
+// REF: https://github.com/aspnet/Entropy/blob/dev/samples/Mvc.CustomRoutingConvention/NameSpaceRoutingConvention.cs
+// REF: https://github.com/aspnet/Mvc/issues/5691
+using System;
+
+namespace JsonApiDotNetCore.Internal
+{
+    public interface IControllerResourceMapping
+    {
+        Type GetAssociatedResource(string controllerName);
+    }
+}