Fix/pagesize (#601)

* feat: new startup for test

* chore: rename startup class

* test: reproduce #599 in test

* fix: zero division error

* chore: remove redundant DefaultPageSize on IPageService

* chore: update .gitignore

Author: maurei

src/Examples/JsonApiDotNetCoreExample/Startups/ClientGeneratedIdsStartup.cs

@@ -15,8 +15,8 @@ namespace JsonApiDotNetCoreExample
     public class ClientGeneratedIdsStartup : Startup
     {
         public ClientGeneratedIdsStartup(IWebHostEnvironment env)
-        : base (env)
-        {  }
+        : base(env)
+        { }
 
         public override void ConfigureServices(IServiceCollection services)
         {
@@ -41,4 +41,4 @@ public override void ConfigureServices(IServiceCollection services)
                 mvcBuilder: mvcBuilder);
         }
     }
-}
+}

src/Examples/JsonApiDotNetCoreExample/Startups/NoDefaultPageSizeStartup.cs

@@ -0,0 +1,43 @@
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using JsonApiDotNetCoreExample.Data;
+using Microsoft.EntityFrameworkCore;
+using JsonApiDotNetCore.Extensions;
+using System.Reflection;
+
+namespace JsonApiDotNetCoreExample
+{
+    /// <summary>
+    /// This should be in JsonApiDotNetCoreExampleTests project but changes in .net core 3.0
+    /// do no longer allow that. See https://github.com/aspnet/AspNetCore/issues/15373.
+    /// </summary>
+    public class NoDefaultPageSizeStartup : Startup
+    {
+        public NoDefaultPageSizeStartup(IWebHostEnvironment env)
+        : base(env)
+        { }
+
+        public override void ConfigureServices(IServiceCollection services)
+        {
+            var loggerFactory = new LoggerFactory();
+            var mvcBuilder = services.AddMvcCore();
+            services
+                .AddSingleton<ILoggerFactory>(loggerFactory)
+                .AddLogging(builder =>
+                {
+                    builder.AddConsole();
+                })
+                .AddDbContext<AppDbContext>(options => options.UseNpgsql(GetDbConnectionString()), ServiceLifetime.Transient)
+                .AddJsonApi(options => {
+                    options.Namespace = "api/v1";
+                    options.IncludeTotalRecordCount = true;
+                    options.EnableResourceHooks = true;
+                    options.LoaDatabaseValues = true;
+                    options.AllowClientGeneratedIds = true;
+                },
+                discovery => discovery.AddAssembly(Assembly.Load(nameof(JsonApiDotNetCoreExample))),
+                mvcBuilder: mvcBuilder);
+        }
+    }
+}

src/JsonApiDotNetCore/QueryParameterServices/Contracts/IPageService.cs

@@ -14,19 +14,13 @@ public interface IPageService : IQueryParameterService
         /// </summary>
         int PageSize { get; set; }
         /// <summary>
-        /// What is the default page size
-        /// </summary>
-        int DefaultPageSize { get; set; }
-        /// <summary>
         /// What page are we currently on
         /// </summary>
         int CurrentPage { get; set; }
-
         /// <summary>
         /// Total amount of pages for request
         /// </summary>
         int TotalPages { get; }
-
         /// <summary>
         /// Checks if pagination is enabled
         /// </summary>

src/JsonApiDotNetCore/QueryParameterServices/PageService.cs

@@ -15,19 +15,16 @@ public class PageService : QueryParameterService, IPageService
         public PageService(IJsonApiOptions options)
         {
             _options = options;
-            DefaultPageSize = _options.DefaultPageSize;
             PageSize = _options.DefaultPageSize;
         }
         /// <inheritdoc/>
         public int? TotalRecords { get; set; }
         /// <inheritdoc/>
         public int PageSize { get; set; }
         /// <inheritdoc/>
-        public int DefaultPageSize { get; set; } // I think we shouldnt expose this
-        /// <inheritdoc/>
         public int CurrentPage { get; set; }
         /// <inheritdoc/>
-        public int TotalPages => (TotalRecords == null) ? -1 : (int)Math.Ceiling(decimal.Divide(TotalRecords.Value, PageSize));
+        public int TotalPages => (TotalRecords == null || PageSize == 0) ? -1 : (int)Math.Ceiling(decimal.Divide(TotalRecords.Value, PageSize));
 
         /// <inheritdoc/>
         public virtual void Parse(KeyValuePair<string, StringValues> queryParameter)

test/JsonApiDotNetCoreExampleTests/Acceptance/Spec/FetchingDataTests.cs

@@ -1,4 +1,5 @@
-using System.Net;
+using System.Linq;
+using System.Net;
 using System.Net.Http;
 using System.Threading.Tasks;
 using Bogus;
@@ -96,5 +97,31 @@ public async Task Included_Records_Contain_Relationship_Links()
             Assert.Equal($"http://localhost/api/v1/people/{person.Id}/relationships/todo-items", deserializedBody.Included[0].Relationships["todo-items"].Links.Self);
             context.Dispose();
         }
+
+        [Fact]
+        public async Task GetResources_NoDefaultPageSize_ReturnsResources()
+        {
+            // Arrange
+            var context = _fixture.GetService<AppDbContext>();
+            var todoItems = _todoItemFaker.Generate(20).ToList();
+            context.TodoItems.AddRange(todoItems);
+            await context.SaveChangesAsync();
+
+            var builder = new WebHostBuilder()
+                .UseStartup<NoDefaultPageSizeStartup>();
+            var httpMethod = new HttpMethod("GET");
+            var route = $"/api/v1/todo-items";
+            var server = new TestServer(builder);
+            var client = server.CreateClient();
+            var request = new HttpRequestMessage(httpMethod, route);
+
+            // Act
+            var response = await client.SendAsync(request);
+            var body = await response.Content.ReadAsStringAsync();
+            var result = _fixture.GetDeserializer().DeserializeList<TodoItem>(body);
+
+            // Assert
+            Assert.True(result.Data.Count >= 20);
+        }
     }
 }