Added pageInfo as connection flag (#8153)

michaelstaib · michaelstaib · commit efa4da51d49b · 2025-03-19T12:26:04.000+01:00
diff --git a/src/HotChocolate/Core/src/Types/Resolvers/Expressions/Parameters/ConnectionFlagsParameterExpressionBuilder.cs b/src/HotChocolate/Core/src/Types/Resolvers/Expressions/Parameters/ConnectionFlagsParameterExpressionBuilder.cs
@@ -34,24 +34,5 @@ public T Execute<T>(IResolverContext context)
         => (T)(object)Execute(context);
 
     private static ConnectionFlags Execute(IResolverContext context)
-    {
-        var flags = ConnectionFlags.None;
-
-        if (context.IsSelected("totalCount"))
-        {
-            flags |= ConnectionFlags.TotalCount;
-        }
-
-        if (context.IsSelected("edges"))
-        {
-            flags |= ConnectionFlags.Edges;
-        }
-
-        if (context.IsSelected("nodes"))
-        {
-            flags |= ConnectionFlags.Nodes;
-        }
-
-        return flags;
-    }
+        => ConnectionFlagsHelper.GetConnectionFlags(context);
 }
diff --git a/src/HotChocolate/Core/src/Types/Types/Pagination/ConnectionFlags.cs b/src/HotChocolate/Core/src/Types/Types/Pagination/ConnectionFlags.cs
@@ -27,17 +27,17 @@ public enum ConnectionFlags
     TotalCount = 4,
 
     /// <summary>
-    /// The relative cursor field was requested by the user.
+    /// The page info field was requested by the user.
     /// </summary>
-    RelativeCursor = 8,
+    PageInfo = 8,
 
     /// <summary>
-    /// The nodes or edges field was requested by the user.
+    /// The relative cursor field was requested by the user.
     /// </summary>
-    NodesOrEdges = Edges | Nodes,
+    RelativeCursor = 16,
 
     /// <summary>
     /// All fields were requested by the user.
     /// </summary>
-    All = Edges | Nodes | TotalCount | RelativeCursor
+    All = Edges | Nodes | TotalCount | PageInfo | RelativeCursor
 }
diff --git a/src/HotChocolate/Core/src/Types/Types/Pagination/ConnectionFlagsHelper.cs b/src/HotChocolate/Core/src/Types/Types/Pagination/ConnectionFlagsHelper.cs
@@ -1,4 +1,5 @@
 using System.Collections.Concurrent;
+using System.Collections.Immutable;
 using HotChocolate.Language;
 using HotChocolate.Resolvers;
 using HotChocolate.Types.Descriptors.Definitions;
@@ -23,7 +24,7 @@ public static ConnectionFlags GetConnectionFlags(IResolverContext context)
             string.Format(_keyFormat, context.Selection.Id),
             static (_, ctx) =>
             {
-                if(ctx.Selection.Field is ObjectField field
+                if (ctx.Selection.Field is ObjectField field
                     && !field.Flags.HasFlag(FieldFlags.Connection))
                 {
                     return ConnectionFlags.None;
@@ -33,48 +34,42 @@ public static ConnectionFlags GetConnectionFlags(IResolverContext context)
 
                 var connectionFlags = ConnectionFlags.None;
 
-                if(ctx.IsSelected("edges"))
+                if (ctx.IsSelected("edges"))
                 {
                     connectionFlags |= ConnectionFlags.Edges;
                 }
 
-                if(ctx.IsSelected("nodes"))
+                if (ctx.IsSelected("nodes"))
                 {
                     connectionFlags |= ConnectionFlags.Nodes;
                 }
 
-                if(ctx.IsSelected("totalCount"))
+                if (ctx.IsSelected("totalCount"))
                 {
                     connectionFlags |= ConnectionFlags.TotalCount;
                 }
 
-                if ((options.EnableRelativeCursors ?? PagingDefaults.EnableRelativeCursors)
-                    && options.RelativeCursorFields.Count > 0)
+                if (options.PageInfoFields.Count > 0
+                    || ((options.EnableRelativeCursors ?? PagingDefaults.EnableRelativeCursors)
+                        && options.RelativeCursorFields.Count > 0))
                 {
                     var startSelections = ctx.Select();
                     var selectionContext = new IsSelectedContext(ctx.Schema, startSelections);
 
-                    foreach (var relativeCursor in options.RelativeCursorFields)
+                    if (options.PageInfoFields.Count > 0)
                     {
-                        // we reset the state here so that each visitation starts fresh.
-                        selectionContext.AllSelected = true;
-                        selectionContext.Selections.Clear();
-                        selectionContext.Selections.Push(startSelections);
-
-                        // we parse the selection pattern, we in essence use
-                        // a SelectionSetNode as a selection pattern.
-                        var selectionPattern = ParsePattern(relativeCursor);
-
-                        // then we visit the selection and if one selection of the selection pattern
-                        // is not hit we break the loop and do not set the relative cursor flag.
-                        IsSelectedVisitor.Instance.Visit(selectionPattern, selectionContext);
-
-                        // if however all selections of the selection pattern are
-                        // hit we set the relative cursor flag.
-                        if (selectionContext.AllSelected)
+                        if (ArePatternsMatched(startSelections, selectionContext, options.PageInfoFields))
+                        {
+                            connectionFlags |= ConnectionFlags.PageInfo;
+                        }
+                    }
+
+                    if ((options.EnableRelativeCursors ?? PagingDefaults.EnableRelativeCursors)
+                        && options.RelativeCursorFields.Count > 0)
+                    {
+                        if (ArePatternsMatched(startSelections, selectionContext, options.RelativeCursorFields))
                         {
                             connectionFlags |= ConnectionFlags.RelativeCursor;
-                            break;
                         }
                     }
                 }
@@ -84,6 +79,37 @@ public static ConnectionFlags GetConnectionFlags(IResolverContext context)
             context);
     }
 
+    private static bool ArePatternsMatched(
+        ISelectionCollection startSelections,
+        IsSelectedContext selectionContext,
+        ImmutableHashSet<string> patterns)
+    {
+        foreach (var fieldPattern in patterns)
+        {
+            // we reset the state here so that each visitation starts fresh.
+            selectionContext.AllSelected = true;
+            selectionContext.Selections.Clear();
+            selectionContext.Selections.Push(startSelections);
+
+            // we parse the selection pattern, we in essence use
+            // a SelectionSetNode as a selection pattern.
+            var selectionPattern = ParsePattern(fieldPattern);
+
+            // then we visit the selection and if one selection of the selection pattern
+            // is not hit we break the loop and signal that the pattern was not hit.
+            IsSelectedVisitor.Instance.Visit(selectionPattern, selectionContext);
+
+            // if however all selections of the selection pattern are
+            // hit we exit early and return true.
+            if (selectionContext.AllSelected)
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     private static SelectionSetNode ParsePattern(string selectionSet)
         => _parsedSelectionSets.GetOrAdd(selectionSet, static s => ParseSelectionSet($"{{ {s} }}"));
 }
diff --git a/src/HotChocolate/Core/src/Types/Types/Pagination/PagingOptions.cs b/src/HotChocolate/Core/src/Types/Types/Pagination/PagingOptions.cs
@@ -70,7 +70,21 @@ public class PagingOptions
     /// Gets or sets the fields that represent relative cursors.
     /// </summary>
     public ImmutableHashSet<string> RelativeCursorFields { get; set; } =
-        ["pageInfo { forwardCursors }", "pageInfo { backwardCursors }"];
+        [
+            "pageInfo { forwardCursors }",
+            "pageInfo { backwardCursors }"
+        ];
+
+    /// <summary>
+    /// Gets or sets the fields that represent page infos like hasNextPage or startCursor.
+    /// </summary>
+    public ImmutableHashSet<string> PageInfoFields { get; set; } =
+        [
+            "pageInfo { startCursor }",
+            "pageInfo { endCursor }" ,
+            "pageInfo { hasNextPage }" ,
+            "pageInfo { hasPreviousPage }"
+        ];
 
     /// <summary>
     /// Merges the <paramref name="other"/> options into this options instance wherever
@@ -92,6 +106,7 @@ internal void Merge(PagingOptions other)
         IncludeNodesField ??= other.IncludeNodesField;
         EnableRelativeCursors ??= other.EnableRelativeCursors;
         RelativeCursorFields = RelativeCursorFields.Union(other.RelativeCursorFields);
+        PageInfoFields = PageInfoFields.Union(other.PageInfoFields);
     }
 
     /// <summary>
@@ -110,6 +125,7 @@ internal PagingOptions Copy()
             ProviderName = ProviderName,
             IncludeNodesField = IncludeNodesField,
             EnableRelativeCursors = EnableRelativeCursors,
-            RelativeCursorFields = RelativeCursorFields
+            RelativeCursorFields = RelativeCursorFields,
+            PageInfoFields = PageInfoFields
         };
 }
diff --git a/src/HotChocolate/Data/test/Data.PostgreSQL.Tests/IntegrationTests.cs b/src/HotChocolate/Data/test/Data.PostgreSQL.Tests/IntegrationTests.cs
@@ -313,6 +313,32 @@ public async Task Query_Brands_First_2_Products_First_2_ForwardCursors()
         MatchSnapshot(result, interceptor);
     }
 
+    [Fact]
+    public async Task Verify_That_PageInfo_Flag_Is_Correctly_Inferred()
+    {
+        // arrange
+        using var interceptor = new TestQueryInterceptor();
+
+        // act
+        var result = await ExecuteAsync(
+            """
+            {
+                brands(first: 1) {
+                    nodes {
+                        products(first: 2) {
+                            pageInfo {
+                                endCursor
+                            }
+                        }
+                    }
+                }
+            }
+            """);
+
+        // assert
+        MatchSnapshot(result, interceptor);
+    }
+
     [Fact]
     public async Task Query_Products_Include_TotalCount()
     {
diff --git a/src/HotChocolate/Data/test/Data.PostgreSQL.Tests/Types/Brands/BrandNode.cs b/src/HotChocolate/Data/test/Data.PostgreSQL.Tests/Types/Brands/BrandNode.cs
@@ -22,6 +22,12 @@ public static async Task<PageConnection<Product>> GetProductsAsync(
         ISelection selection,
         CancellationToken cancellationToken)
     {
+        // we for test purposes only return an empty page if the connection flags are set to PageInfo
+        if(connectionFlags == ConnectionFlags.PageInfo)
+        {
+            return new PageConnection<Product>(Page<Product>.Empty);
+        }
+
         var page = await productService.GetProductsByBrandAsync(brand.Id, pagingArgs, query, cancellationToken);
         return new PageConnection<Product>(page);
     }
diff --git a/src/HotChocolate/Data/test/Data.PostgreSQL.Tests/__snapshots__/IntegrationTests.Verify_That_PageInfo_Flag_Is_Correctly_Inferred.md b/src/HotChocolate/Data/test/Data.PostgreSQL.Tests/__snapshots__/IntegrationTests.Verify_That_PageInfo_Flag_Is_Correctly_Inferred.md
@@ -0,0 +1,32 @@
+# Verify_That_PageInfo_Flag_Is_Correctly_Inferred
+
+## Result
+
+```json
+{
+  "data": {
+    "brands": {
+      "nodes": [
+        {
+          "products": {
+            "pageInfo": {
+              "endCursor": null
+            }
+          }
+        }
+      ]
+    }
+  }
+}
+```
+
+## Query 1
+
+```sql
+-- @__p_0='2'
+SELECT b."Id", b."Name"
+FROM "Brands" AS b
+ORDER BY b."Name" DESC, b."Id"
+LIMIT @__p_0
+```
+
diff --git a/src/HotChocolate/Data/test/Data.PostgreSQL.Tests/__snapshots__/IntegrationTests.Verify_That_PageInfo_Flag_Is_Correctly_Inferred__net_8_0.md b/src/HotChocolate/Data/test/Data.PostgreSQL.Tests/__snapshots__/IntegrationTests.Verify_That_PageInfo_Flag_Is_Correctly_Inferred__net_8_0.md
@@ -0,0 +1,32 @@
+# Verify_That_PageInfo_Flag_Is_Correctly_Inferred
+
+## Result
+
+```json
+{
+  "data": {
+    "brands": {
+      "nodes": [
+        {
+          "products": {
+            "pageInfo": {
+              "endCursor": null
+            }
+          }
+        }
+      ]
+    }
+  }
+}
+```
+
+## Query 1
+
+```sql
+-- @__p_0='2'
+SELECT b."Id", b."Name"
+FROM "Brands" AS b
+ORDER BY b."Name" DESC, b."Id"
+LIMIT @__p_0
+```
+

Original file line number	Diff line number	Diff line change
`@@ -22,6 +22,12 @@ public static async Task<PageConnection<Product>> GetProductsAsync(`
`22`	`22`	`ISelection selection,`
`23`	`23`	`CancellationToken cancellationToken)`
`24`	`24`	`{`
	`25`	`+ // we for test purposes only return an empty page if the connection flags are set to PageInfo`
	`26`	`+ if(connectionFlags == ConnectionFlags.PageInfo)`
	`27`	`+ {`
	`28`	`+ return new PageConnection<Product>(Page<Product>.Empty);`
	`29`	`+ }`
	`30`	`+`
`25`	`31`	`var page = await productService.GetProductsByBrandAsync(brand.Id, pagingArgs, query, cancellationToken);`
`26`	`32`	`return new PageConnection<Product>(page);`
`27`	`33`	`}`