Added fluent paging helpers (#4277)

src/HotChocolate/Core/src/Types.CursorPagination/Extensions/CursorPagingQueryableExtensions.cs

@@ -1,6 +1,8 @@
+using System;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using HotChocolate.Resolvers;
 
 namespace HotChocolate.Types.Pagination.Extensions
 {
@@ -76,5 +78,106 @@ public static ValueTask<Connection<TEntity>> ApplyCursorPaginationAsync<TEntity>
                 query,
                 arguments,
                 cancellationToken);
+
+        /// <summary>
+        /// Applies the cursor pagination algorithm to the <paramref name="query"/>.
+        /// </summary>
+        /// <param name="query">
+        /// The query on which the the cursor pagination algorithm shall be applied to.
+        /// </param>
+        /// <param name="context">
+        /// The field resolver context.
+        /// </param>
+        /// <param name="defaultPageSize">
+        /// The default page size if no boundaries are set.
+        /// </param>
+        /// <param name="totalCount">
+        /// The total count if already known.
+        /// </param>
+        /// <param name="cancellationToken">
+        /// The cancellation token.
+        /// </param>
+        /// <typeparam name="TEntity">
+        /// The entity type.
+        /// </typeparam>
+        /// <returns>
+        /// Returns a connection instance that represents the result of applying the
+        /// cursor paging algorithm to the provided <paramref name="query"/>.
+        /// </returns>
+        public static ValueTask<Connection<TEntity>> ApplyCursorPaginationAsync<TEntity>(
+            this IQueryable<TEntity> query,
+            IResolverContext context,
+            int? defaultPageSize = null,
+            int? totalCount = null,
+            CancellationToken cancellationToken = default)
+        {
+            if (query is null)
+            {
+                throw new ArgumentNullException(nameof(query));
+            }
+
+            if (context is null)
+            {
+                throw new ArgumentNullException(nameof(context));
+            }
+
+            var first = context.ArgumentValue<int?>(CursorPagingArgumentNames.First);
+            var last = context.ArgumentValue<int?>(CursorPagingArgumentNames.Last);
+
+            if (first is null && last is null)
+            {
+                first = defaultPageSize;
+            }
+
+            var arguments = new CursorPagingArguments(
+                first,
+                last,
+                context.ArgumentValue<string?>(CursorPagingArgumentNames.After),
+                context.ArgumentValue<string?>(CursorPagingArgumentNames.Before));
+
+            return QueryableCursorPagination<TEntity>.Instance.ApplyPaginationAsync(
+                query,
+                arguments,
+                totalCount,
+                cancellationToken);
+        }
+
+        /// <summary>
+        /// Applies the cursor pagination algorithm to the <paramref name="enumerable"/>.
+        /// </summary>
+        /// <param name="enumerable">
+        /// The enumerable on which the the cursor pagination algorithm shall be applied to.
+        /// </param>
+        /// <param name="context">
+        /// The field resolver context.
+        /// </param>
+        /// <param name="defaultPageSize">
+        /// The default page size if no boundaries are set.
+        /// </param>
+        /// <param name="totalCount">
+        /// The total count if already known.
+        /// </param>
+        /// <param name="cancellationToken">
+        /// The cancellation token.
+        /// </param>
+        /// <typeparam name="TEntity">
+        /// The entity type.
+        /// </typeparam>
+        /// <returns>
+        /// Returns a connection instance that represents the result of applying the
+        /// cursor paging algorithm to the provided <paramref name="enumerable"/>.
+        /// </returns>
+        public static ValueTask<Connection<TEntity>> ApplyCursorPaginationAsync<TEntity>(
+            this System.Collections.Generic.IEnumerable<TEntity> enumerable,
+            IResolverContext context,
+            int? defaultPageSize = null,
+            int? totalCount = null,
+            CancellationToken cancellationToken = default)
+            => ApplyCursorPaginationAsync(
+                enumerable.AsQueryable(),
+                context,
+                defaultPageSize,
+                totalCount,
+                cancellationToken);
     }
 }

src/HotChocolate/Core/test/Types.CursorPagination.Tests/CursorPagingQueryableExtensionsTests.cs

@@ -0,0 +1,162 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using HotChocolate.Execution;
+using HotChocolate.Resolvers;
+using HotChocolate.Tests;
+using HotChocolate.Types.Pagination.Extensions;
+using Microsoft.Extensions.DependencyInjection;
+using Moq;
+using Snapshooter.Xunit;
+using Xunit;
+
+namespace HotChocolate.Types.Pagination
+{
+    public class CursorPagingQueryableExtensionsTests
+    {
+        [Fact]
+        public async Task Queryable_Query_Is_Null()
+        {
+            var mock = new Mock<IResolverContext>();
+
+            async Task Fail()
+                => await default(IQueryable<Person>)!.ApplyCursorPaginationAsync(mock.Object);
+
+            await Assert.ThrowsAsync<ArgumentNullException>(Fail);
+        }
+
+        [Fact]
+        public async Task Queryable_Context_Is_Null()
+        {
+            var mock = new Mock<IQueryable<Person>>();
+
+            async Task Fail()
+                => await mock.Object.ApplyCursorPaginationAsync(default(IResolverContext)!);
+
+            await Assert.ThrowsAsync<ArgumentNullException>(Fail);
+        }
+
+        [Fact]
+        public async Task Queryable_ApplyCursorPaginationAsync_No_Boundaries()
+        {
+            Snapshot.FullName();
+
+            await new ServiceCollection()
+                .AddGraphQL()
+                .AddQueryType<Query>()
+                .ExecuteRequestAsync("{ persons { nodes { name } } }")
+                .MatchSnapshotAsync();
+        }
+
+        [Fact]
+        public async Task Queryable_ApplyCursorPaginationAsync_First_1()
+        {
+            Snapshot.FullName();
+
+            await new ServiceCollection()
+                .AddGraphQL()
+                .AddQueryType<Query>()
+                .ExecuteRequestAsync("{ persons(first: 1) { nodes { name } } }")
+                .MatchSnapshotAsync();
+        }
+
+        [Fact]
+        public async Task Enumerable_Query_Is_Null()
+        {
+            var mock = new Mock<IResolverContext>();
+
+            async Task Fail()
+                => await default(IEnumerable<Person>)!.ApplyCursorPaginationAsync(mock.Object);
+
+            await Assert.ThrowsAsync<ArgumentNullException>(Fail);
+        }
+
+        [Fact]
+        public async Task Enumerable_Context_Is_Null()
+        {
+            var mock = new Mock<IEnumerable<Person>>();
+
+            async Task Fail()
+                => await mock.Object.ApplyCursorPaginationAsync(default(IResolverContext)!);
+
+            await Assert.ThrowsAsync<ArgumentNullException>(Fail);
+        }
+
+        [Fact]
+        public async Task Enumerable_ApplyCursorPaginationAsync_No_Boundaries()
+        {
+            Snapshot.FullName();
+
+            await new ServiceCollection()
+                .AddGraphQL()
+                .AddQueryType<QueryEnumerable>()
+                .ExecuteRequestAsync("{ persons { nodes { name } } }")
+                .MatchSnapshotAsync();
+        }
+
+        [Fact]
+        public async Task Enumerable_ApplyCursorPaginationAsync_First_1()
+        {
+            Snapshot.FullName();
+
+            await new ServiceCollection()
+                .AddGraphQL()
+                .AddQueryType<QueryEnumerable>()
+                .ExecuteRequestAsync("{ persons(first: 1) { nodes { name } } }")
+                .MatchSnapshotAsync();
+        }
+
+        public class Query
+        {
+            [UsePaging]
+            public async Task<Connection<Person>> GetPersons(
+                IResolverContext context,
+                CancellationToken cancellationToken)
+            {
+                var list = new Person[]
+                {
+                    new() { Name = "Foo" },
+                    new() { Name = "Bar" },
+                    new() { Name = "Baz" },
+                    new() { Name = "Qux" }
+                };
+
+                return await list.AsQueryable().ApplyCursorPaginationAsync(
+                    context,
+                    defaultPageSize: 2,
+                    totalCount: list.Length,
+                    cancellationToken: cancellationToken);
+            }
+        }
+
+        public class QueryEnumerable
+        {
+            [UsePaging]
+            public async Task<Connection<Person>> GetPersons(
+                IResolverContext context,
+                CancellationToken cancellationToken)
+            {
+                var list = new Person[]
+                {
+                    new() { Name = "Foo" },
+                    new() { Name = "Bar" },
+                    new() { Name = "Baz" },
+                    new() { Name = "Qux" }
+                };
+
+                return await list.ApplyCursorPaginationAsync(
+                    context,
+                    defaultPageSize: 2,
+                    totalCount: list.Length,
+                    cancellationToken: cancellationToken);
+            }
+        }
+
+        public class Person
+        {
+            public string Name { get; set; }
+        }
+    }
+}

src/HotChocolate/Core/test/Types.CursorPagination.Tests/__snapshots__/CursorPagingQueryableExtensionsTests.Enumerable_ApplyCursorPaginationAsync_First_1.snap

@@ -0,0 +1,11 @@
+{
+  "data": {
+    "persons": {
+      "nodes": [
+        {
+          "name": "Foo"
+        }
+      ]
+    }
+  }
+}

src/HotChocolate/Core/test/Types.CursorPagination.Tests/__snapshots__/CursorPagingQueryableExtensionsTests.Enumerable_ApplyCursorPaginationAsync_No_Boundaries.snap

@@ -0,0 +1,14 @@
+{
+  "data": {
+    "persons": {
+      "nodes": [
+        {
+          "name": "Foo"
+        },
+        {
+          "name": "Bar"
+        }
+      ]
+    }
+  }
+}

src/HotChocolate/Core/test/Types.CursorPagination.Tests/__snapshots__/CursorPagingQueryableExtensionsTests.Queryable_ApplyCursorPaginationAsync_First_1.snap

@@ -0,0 +1,11 @@
+{
+  "data": {
+    "persons": {
+      "nodes": [
+        {
+          "name": "Foo"
+        }
+      ]
+    }
+  }
+}

src/HotChocolate/Core/test/Types.CursorPagination.Tests/__snapshots__/CursorPagingQueryableExtensionsTests.Queryable_ApplyCursorPaginationAsync_No_Boundaries.snap

@@ -0,0 +1,14 @@
+{
+  "data": {
+    "persons": {
+      "nodes": [
+        {
+          "name": "Foo"
+        },
+        {
+          "name": "Bar"
+        }
+      ]
+    }
+  }
+}