Move parsing of include chains into base class

Author: bkoelman

src/JsonApiDotNetCore/Queries/Parsing/IncludeParser.cs

@@ -1,9 +1,5 @@
-using System.Collections.Immutable;
-using System.Collections.ObjectModel;
-using System.Text;
 using JetBrains.Annotations;
 using JsonApiDotNetCore.Configuration;
-using JsonApiDotNetCore.Errors;
 using JsonApiDotNetCore.Queries.Expressions;
 using JsonApiDotNetCore.Resources.Annotations;
 
@@ -61,158 +57,6 @@ protected virtual IncludeExpression ParseInclude(ResourceType resourceType)
         return treeRoot.ToExpression();
     }
 
-    private void ParseRelationshipChain(IncludeTreeNode treeRoot)
-    {
-        // A relationship name usually matches a single relationship, even when overridden in derived types.
-        // But in the following case, two relationships are matched on GET /shoppingBaskets?include=items:
-        //
-        // public abstract class ShoppingBasket : Identifiable<long>
-        // {
-        // }
-        //
-        // public sealed class SilverShoppingBasket : ShoppingBasket
-        // {
-        //     [HasMany]
-        //     public ISet<Article> Items { get; get; }
-        // }
-        //
-        // public sealed class PlatinumShoppingBasket : ShoppingBasket
-        // {
-        //     [HasMany]
-        //     public ISet<Product> Items { get; get; }
-        // }
-        //
-        // Now if the include chain has subsequent relationships, we need to scan both Items relationships for matches,
-        // which is why ParseRelationshipName returns a collection.
-        //
-        // The advantage of this unfolding is we don't require callers to upcast in relationship chains. The downside is
-        // that there's currently no way to include Products without Articles. We could add such optional upcast syntax
-        // in the future, if desired.
-
-        ReadOnlyCollection<IncludeTreeNode> children = ParseRelationshipName([treeRoot]);
-
-        while (TokenStack.TryPeek(out Token? nextToken) && nextToken.Kind == TokenKind.Period)
-        {
-            EatSingleCharacterToken(TokenKind.Period);
-
-            children = ParseRelationshipName(children);
-        }
-    }
-
-    private ReadOnlyCollection<IncludeTreeNode> ParseRelationshipName(IReadOnlyCollection<IncludeTreeNode> parents)
-    {
-        int position = GetNextTokenPositionOrEnd();
-
-        if (TokenStack.TryPop(out Token? token) && token.Kind == TokenKind.Text)
-        {
-            return LookupRelationshipName(token.Value!, parents, position);
-        }
-
-        throw new QueryParseException("Relationship name expected.", position);
-    }
-
-    private ReadOnlyCollection<IncludeTreeNode> LookupRelationshipName(string relationshipName, IReadOnlyCollection<IncludeTreeNode> parents, int position)
-    {
-        List<IncludeTreeNode> children = [];
-        HashSet<RelationshipAttribute> relationshipsFound = [];
-
-        foreach (IncludeTreeNode parent in parents)
-        {
-            // Depending on the left side of the include chain, we may match relationships anywhere in the resource type hierarchy.
-            // This is compensated for when rendering the response, which substitutes relationships on base types with the derived ones.
-            HashSet<RelationshipAttribute> relationships = GetRelationshipsInConcreteTypes(parent.Relationship.RightType, relationshipName);
-
-            if (relationships.Count > 0)
-            {
-                relationshipsFound.UnionWith(relationships);
-
-                RelationshipAttribute[] relationshipsToInclude = relationships.Where(relationship => !relationship.IsIncludeBlocked()).ToArray();
-                ReadOnlyCollection<IncludeTreeNode> affectedChildren = parent.EnsureChildren(relationshipsToInclude);
-                children.AddRange(affectedChildren);
-            }
-        }
-
-        AssertRelationshipsFound(relationshipsFound, relationshipName, parents, position);
-        AssertAtLeastOneCanBeIncluded(relationshipsFound, relationshipName, position);
-
-        return children.AsReadOnly();
-    }
-
-    private static HashSet<RelationshipAttribute> GetRelationshipsInConcreteTypes(ResourceType resourceType, string relationshipName)
-    {
-        HashSet<RelationshipAttribute> relationshipsToInclude = [];
-
-        foreach (RelationshipAttribute relationship in resourceType.GetRelationshipsInTypeOrDerived(relationshipName))
-        {
-            if (!relationship.LeftType.ClrType.IsAbstract)
-            {
-                relationshipsToInclude.Add(relationship);
-            }
-
-            IncludeRelationshipsFromConcreteDerivedTypes(relationship, relationshipsToInclude);
-        }
-
-        return relationshipsToInclude;
-    }
-
-    private static void IncludeRelationshipsFromConcreteDerivedTypes(RelationshipAttribute relationship, HashSet<RelationshipAttribute> relationshipsToInclude)
-    {
-        foreach (ResourceType derivedType in relationship.LeftType.GetAllConcreteDerivedTypes())
-        {
-            RelationshipAttribute relationshipInDerived = derivedType.GetRelationshipByPublicName(relationship.PublicName);
-            relationshipsToInclude.Add(relationshipInDerived);
-        }
-    }
-
-    private static void AssertRelationshipsFound(HashSet<RelationshipAttribute> relationshipsFound, string relationshipName,
-        IReadOnlyCollection<IncludeTreeNode> parents, int position)
-    {
-        if (relationshipsFound.Count > 0)
-        {
-            return;
-        }
-
-        ResourceType[] parentResourceTypes = parents.Select(parent => parent.Relationship.RightType).Distinct().ToArray();
-
-        bool hasDerivedTypes = parents.Any(parent => parent.Relationship.RightType.DirectlyDerivedTypes.Count > 0);
-
-        string message = GetErrorMessageForNoneFound(relationshipName, parentResourceTypes, hasDerivedTypes);
-        throw new QueryParseException(message, position);
-    }
-
-    private static string GetErrorMessageForNoneFound(string relationshipName, ResourceType[] parentResourceTypes, bool hasDerivedTypes)
-    {
-        var builder = new StringBuilder($"Relationship '{relationshipName}'");
-
-        if (parentResourceTypes.Length == 1)
-        {
-            builder.Append($" does not exist on resource type '{parentResourceTypes.First().PublicName}'");
-        }
-        else
-        {
-            string typeNames = string.Join(", ", parentResourceTypes.Select(type => $"'{type.PublicName}'"));
-            builder.Append($" does not exist on any of the resource types {typeNames}");
-        }
-
-        builder.Append(hasDerivedTypes ? " or any of its derived types." : ".");
-
-        return builder.ToString();
-    }
-
-    private void AssertAtLeastOneCanBeIncluded(HashSet<RelationshipAttribute> relationshipsFound, string relationshipName, int position)
-    {
-        if (relationshipsFound.All(relationship => relationship.IsIncludeBlocked()))
-        {
-            ResourceType resourceType = relationshipsFound.First().LeftType;
-            string message = $"Including the relationship '{relationshipName}' on '{resourceType}' is not allowed.";
-
-            var exception = new QueryParseException(message, position);
-            string specificMessage = exception.GetMessageWithPosition(Source);
-
-            throw new InvalidQueryStringParameterException("include", "The specified include is invalid.", specificMessage);
-        }
-    }
-
     private void ValidateMaximumIncludeDepth(IncludeExpression include, int position)
     {
         if (_options.MaximumIncludeDepth != null)
@@ -245,71 +89,4 @@ private static void ThrowIfMaximumDepthExceeded(IncludeElementExpression include
 
         parentChain.Pop();
     }
-
-    private sealed class IncludeTreeNode
-    {
-        private readonly Dictionary<RelationshipAttribute, IncludeTreeNode> _children = [];
-
-        public RelationshipAttribute Relationship { get; }
-
-        private IncludeTreeNode(RelationshipAttribute relationship)
-        {
-            Relationship = relationship;
-        }
-
-        public static IncludeTreeNode CreateRoot(ResourceType resourceType)
-        {
-            var relationship = new HiddenRootRelationshipAttribute(resourceType);
-            return new IncludeTreeNode(relationship);
-        }
-
-        public ReadOnlyCollection<IncludeTreeNode> EnsureChildren(RelationshipAttribute[] relationships)
-        {
-            foreach (RelationshipAttribute relationship in relationships)
-            {
-                if (!_children.ContainsKey(relationship))
-                {
-                    var newChild = new IncludeTreeNode(relationship);
-                    _children.Add(relationship, newChild);
-                }
-            }
-
-            return _children.Where(pair => relationships.Contains(pair.Key)).Select(pair => pair.Value).ToArray().AsReadOnly();
-        }
-
-        public IncludeExpression ToExpression()
-        {
-            IncludeElementExpression element = ToElementExpression();
-
-            if (element.Relationship is HiddenRootRelationshipAttribute)
-            {
-                return element.Children.Count > 0 ? new IncludeExpression(element.Children) : IncludeExpression.Empty;
-            }
-
-            return new IncludeExpression(ImmutableHashSet.Create(element));
-        }
-
-        private IncludeElementExpression ToElementExpression()
-        {
-            IImmutableSet<IncludeElementExpression> elementChildren = _children.Values.Select(child => child.ToElementExpression()).ToImmutableHashSet();
-            return new IncludeElementExpression(Relationship, elementChildren);
-        }
-
-        public override string ToString()
-        {
-            IncludeExpression include = ToExpression();
-            return include.ToFullString();
-        }
-
-        private sealed class HiddenRootRelationshipAttribute : RelationshipAttribute
-        {
-            public HiddenRootRelationshipAttribute(ResourceType rightType)
-            {
-                ArgumentNullException.ThrowIfNull(rightType);
-
-                RightType = rightType;
-                PublicName = "<<root>>";
-            }
-        }
-    }
 }