Fixed: allow unpaged result when no maximum page size is set

Fixed: having default page size of 0 is dangerous (returns complete tables)

Author: Bart Koelman

src/Examples/JsonApiDotNetCoreExample/Startups/NoDefaultPageSizeStartup.cs

@@ -25,6 +25,7 @@ public override void ConfigureServices(IServiceCollection services)
                     options.IncludeTotalRecordCount = true;
                     options.LoadDatabaseValues = true;
                     options.AllowClientGeneratedIds = true;
+                    options.DefaultPageSize = 0;
                 },
                 discovery => discovery.AddAssembly(Assembly.Load(nameof(JsonApiDotNetCoreExample))),
                 mvcBuilder: mvcBuilder);

src/JsonApiDotNetCore/Configuration/JsonApiOptions.cs

@@ -53,12 +53,12 @@ public class JsonApiOptions : IJsonApiOptions
         public string Namespace { get; set; }
 
         /// <summary>
-        /// The default page size for all resources
+        /// The default page size for all resources. The value zero means: no paging.
         /// </summary>
         /// <example>
         /// <code>options.DefaultPageSize = 10;</code>
         /// </example>
-        public int DefaultPageSize { get; set; }
+        public int DefaultPageSize { get; set; } = 10;
 
         /// <summary>
         /// Optional. When set, limits the maximum page size for all resources.

src/JsonApiDotNetCore/QueryParameterServices/PageService.cs

@@ -105,7 +105,9 @@ public virtual void Parse(string parameterName, StringValues parameterValue)
         private int ParsePageSize(string parameterValue, int? maxValue)
         {
             bool success = int.TryParse(parameterValue, out int number);
-            if (success && number >= 1)
+            int minValue = maxValue != null ? 1 : 0;
+
+            if (success && number >= minValue)
             {
                 if (maxValue == null || number <= maxValue)
                 {
@@ -115,7 +117,7 @@ private int ParsePageSize(string parameterValue, int? maxValue)
 
             var message = maxValue == null
                 ? $"Value '{parameterValue}' is invalid, because it must be a whole number that is greater than zero."
-                : $"Value '{parameterValue}' is invalid, because it must be a whole number that is greater than zero and not higher than {maxValue}.";
+                : $"Value '{parameterValue}' is invalid, because it must be a whole number that is zero or greater and not higher than {maxValue}.";
 
             throw new InvalidQueryStringParameterException("page[size]",
                 "The specified value is not in the range of valid values.", message);

test/JsonApiDotNetCoreExampleTests/Acceptance/Spec/FetchingDataTests.cs

@@ -104,6 +104,9 @@ public async Task GetResources_NoDefaultPageSize_ReturnsResources()
         {
             // Arrange
             var context = _fixture.GetService<AppDbContext>();
+            context.TodoItems.RemoveRange(context.TodoItems);
+            await context.SaveChangesAsync();
+
             var todoItems = _todoItemFaker.Generate(20).ToList();
             context.TodoItems.AddRange(todoItems);
             await context.SaveChangesAsync();
@@ -122,7 +125,7 @@ public async Task GetResources_NoDefaultPageSize_ReturnsResources()
             var result = _fixture.GetDeserializer().DeserializeList<TodoItem>(body);
 
             // Assert
-            Assert.True(result.Data.Count >= 20);
+            Assert.True(result.Data.Count == 20);
         }
 
         [Fact]

test/JsonApiDotNetCoreExampleTests/Acceptance/Spec/UpdatingDataTests.cs

@@ -16,7 +16,6 @@
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using Newtonsoft.Json;
-using NLog.Extensions.Logging;
 using Xunit;
 using Person = JsonApiDotNetCoreExample.Models.Person;
 

test/UnitTests/QueryParameters/PageServiceTests.cs

@@ -46,6 +46,8 @@ public void CanParse_PageService_FailOnMismatch()
         }
 
         [Theory]
+        [InlineData("0", 0, null, false)]
+        [InlineData("0", 0, 50, true)]
         [InlineData("1", 1, null, false)]
         [InlineData("abcde", 0, null, true)]
         [InlineData("", 0, null, true)]
@@ -65,7 +67,7 @@ public void Parse_PageSize_CanParse(string value, int expectedValue, int? maximu
                 Assert.Equal("page[size]", exception.QueryParameterName);
                 Assert.Equal(HttpStatusCode.BadRequest, exception.Error.StatusCode);
                 Assert.Equal("The specified value is not in the range of valid values.", exception.Error.Title);
-                Assert.StartsWith($"Value '{value}' is invalid, because it must be a whole number that is greater than zero", exception.Error.Detail);
+                Assert.StartsWith($"Value '{value}' is invalid, because it must be a whole number that is", exception.Error.Detail);
                 Assert.Equal("page[size]", exception.Error.Source.Parameter);
             }
             else