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Exploring .NET Core 3.0 new API

.NET Core 3.0 is representing a major step for the .NET community. It is interesting to analyze what’s new in the API directly from the compiled bits. In this post I will first explain how to diff .NET Core 3.0 against .NET Core 2.2 with NDepend, and then how to browse diff results.

Arguably the biggest progress of .NET Core 3.0 will be the support for Winforms and WPF on the Windows platform. Since everything is new here, compare to .NET Core 2.2, we won’t analyze this part. However it will be interesting to analyze .NET Fx Winforms/WPF APIs vs .NET Core 3.0 Winforms/WPF APIs in another post (that I finally wrote here).

Analyzing two versions of .NET Core with NDepend

It takes a few minutes to download NDepend trial, install it and start VisualNDepend.exe, and it takes a few minutes to compare .NET Core 3.0 against .NET Core 2.2. If you want to browse the diff on your machine, expect 5 to 10 minutes to get hands-on.

First Start VisualNDepend.exe and click Compare 2 versions of a code base:

How to compare 2 versions of a code base

For both builds, choose Add Assemblies in Folder:

  • Choose C:\Program Files\dotnet\shared\Microsoft.NETCore.App\2.2.2  for Older Build
  • Choose C:\Program Files\dotnet\shared\Microsoft.NETCore.App\3.0.0-preview-27324-5 for Newer Build
Choose assemblies in folder to analyze

Respectively 156 and 161 assemblies are gathered. Click Ok to run two analysis, on older and newer build. Both analysis results will be then diffed automatically.

Ready to compare 2 versions of .NET Core

Querying new API

Let’s start with a few CQLinq code queries to explore the new .NET Core 3.0 APIs:

This query match all new public code elements, including new assemblies, namespace, types, methods and fields:

Use the NDepend query result to browse this large new API set : 5 new assemblies, 83 new namespaces, 297 new types, 4 924 new methods and 307 new fields. Note that code elements with pink background are not matched by the query, they are just here for preserving the code hierarchy in the result:

.NET Core 3.0 new public API

Download here this long list obtained by exporting the query result to excel. For a better result formatting I actually used this refined query to show properly parent assemblies/namespaces/types in excel columns:

It is interesting to just focus on the 297 new public types with the code query below. Download the list here or browse the same list at the end of this post.

New .NET Core 3.0 Public Types

It is also interesting to browse the new 1.101 public methods and 38 public fields added on public types that existed already in .NET Core 2.2.  Download this list here.

API Breaking Changes

NDepend proposes 6 default rules to browse API breaking changes.

These rules matche 19 public types removed from .NET Core 2.2 (see list below) 176 public methods removed and 36 public fields removed

.NET Core 2.2 Types Removed

Listing Methods Changed

Exploring the API evolution is useful for API consumers. For those working on the framework .NET Core itself, it is interesting to also browse implementation changes. The NDepend search by change panel proposes various options for that. Note that this search panel is actually a code query generator. The Edit query button proposes to edit and refine the currently generated query.

Another interesting point is that it is a semantic implementation change. All matched methods do behave differently at runtime. This makes this tool ideal to plan code change review without bothering with formatting and comments change.

Matched code elements can be highlighted in the metric view. From the screenshot above we can see at a glance that System.Xml and System.Data are much more stable than System.RunTime for example. By zooming in the view, we can get more information about which code was churned.

Highlight methods where code was changed

In the query result panel, a code element is underlined when its implementation changed. If you have compiled both source versions on your machine and analyzed those compiled versions, you can right click an underlined method and directly compare the diff in source code.

I hope you see value both in the results offered and in the how-to-diff procedure that can be applied to any .NET code base, assuming you have 2 versions to compare.

New .NET Core 3.0 types

Here is the list of the 297 new types added to .NET Core 3.0.

ParentAssembly Full Name
WindowsBase System.Windows.Markup .ValueSerializerAttribute
System.Xml.Linq System.Xml.XPath.XDocumentExtensions
System.Threading.ThreadPool System.Threading.IThreadPoolWorkItem
System.Threading.Tasks System.Runtime.CompilerServices .AsyncIteratorMethodBuilder
System.Threading.Tasks System.Runtime.CompilerServices .ConfiguredCancelableAsyncEnumerable<T>
System.Text.Json System.Text.Json.JsonCommentHandling
System.Text.Json System.Text.Json.JsonTokenType
System.Text.Json System.Text.Json.JsonDocument
System.Text.Json System.Text.Json.JsonElement
System.Text.Json System.Text.Json .JsonElement+ArrayEnumerator
System.Text.Json System.Text.Json .JsonElement+ObjectEnumerator
System.Text.Json System.Text.Json.JsonProperty
System.Text.Json System.Text.Json.JsonValueType
System.Text.Json System.Text.Json.JsonReaderException
System.Text.Json System.Text.Json.JsonReaderOptions
System.Text.Json System.Text.Json.JsonReaderState
System.Text.Json System.Text.Json.Utf8JsonReader
System.Text.Json System.Text.Json.JsonWriterOptions
System.Text.Json System.Text.Json.JsonWriterState
System.Text.Json System.Text.Json.Utf8JsonWriter
System.Security.Principal.Windows System.Security.Principal .WindowsAccountType
System.Security.Cryptography.Primitives System.Security.Cryptography .PbeEncryptionAlgorithm
System.Security.Cryptography.Primitives System.Security.Cryptography .PbeParameters
System.Security.Cryptography.Algorithms System.Security.Cryptography.AesCcm
System.Security.Cryptography.Algorithms System.Security.Cryptography.AesGcm
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.CornerRadius
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.DurationType
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.Duration
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.GridUnitType
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.GridLength
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.Thickness
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.LayoutCycleException
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.Markup .XamlParseException
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.Automation .ElementNotAvailableException
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.Automation .ElementNotEnabledException
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.Media.Matrix
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.Media.Media3D.Matrix3D
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.Media.Animation.KeyTime
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.Media.Animation .RepeatBehaviorType
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.Media.Animation .RepeatBehavior
System.Runtime.WindowsRuntime.UI.Xaml Windows.UI.Xaml.Controls.Primitives .GeneratorPosition
System.Runtime.WindowsRuntime Windows.UI.Color
System.Runtime.WindowsRuntime Windows.Foundation.Point
System.Runtime.WindowsRuntime Windows.Foundation.Rect
System.Runtime.WindowsRuntime Windows.Foundation.Size
System.Runtime.WindowsRuntime System.WindowsRuntimeSystemExtensions
System.Runtime.WindowsRuntime System.IO .WindowsRuntimeStorageExtensions
System.Runtime.WindowsRuntime System.IO.WindowsRuntimeStreamExtensions
System.Runtime.WindowsRuntime System.Threading.DispatcherQueueHandler
System.Runtime.WindowsRuntime System.Threading.DispatcherQueuePriority
System.Runtime.WindowsRuntime System.Runtime.InteropServices .WindowsRuntime.AsyncInfo
System.Runtime.WindowsRuntime System.Runtime.InteropServices .WindowsRuntime.WindowsRuntimeBuffer
System.Runtime.WindowsRuntime System.Runtime.InteropServices .WindowsRuntime .WindowsRuntimeBufferExtensions
System.Runtime.Serialization System.Runtime.Serialization .ISerializationSurrogateProvider
System.Runtime.Loader System.Runtime.Loader .AssemblyDependencyResolver
System.Runtime.Intrinsics System.MidpointRounding
System.Runtime.Intrinsics System.Runtime.Intrinsics.Vector64
System.Runtime.Intrinsics System.Runtime.Intrinsics.Vector64<T>
System.Runtime.Intrinsics System.Runtime.Intrinsics.Vector128
System.Runtime.Intrinsics System.Runtime.Intrinsics.Vector128<T>
System.Runtime.Intrinsics System.Runtime.Intrinsics.Vector256
System.Runtime.Intrinsics System.Runtime.Intrinsics.Vector256<T>
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86 .FloatComparisonMode
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Aes
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Avx
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Avx2
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Bmi1
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Bmi2
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Fma
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Lzcnt
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Pclmulqdq
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Popcnt
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Sse
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Sse2
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Sse3
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Sse41
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Sse42
System.Runtime.Intrinsics System.Runtime.Intrinsics.X86.Ssse3
System.Runtime.Intrinsics System.Runtime.Intrinsics.Arm.Arm64.Aes
System.Runtime.Intrinsics System.Runtime.Intrinsics.Arm.Arm64.Base
System.Runtime.Intrinsics System.Runtime.Intrinsics.Arm.Arm64.Sha1
System.Runtime.Intrinsics System.Runtime.Intrinsics.Arm.Arm64 .Sha256
System.Runtime.Intrinsics System.Runtime.Intrinsics.Arm.Arm64.Simd
System.Runtime.InteropServices System.Runtime.CompilerServices .IDispatchConstantAttribute
System.Runtime.InteropServices System.Runtime.InteropServices .StandardOleMarshalObject
System.Runtime.InteropServices System.Runtime.InteropServices .NativeLibrary
System.Runtime.Extensions System.AppDomainSetup
System.Runtime.Extensions System.Security.IStackWalk
System.Runtime.Extensions System.Security.PermissionSet
System.Runtime.Extensions System.Security.Permissions .PermissionState
System.Runtime.Extensions System.Runtime.ProfileOptimization
System.Runtime System.ArgIterator
System.Runtime System.IAsyncDisposable
System.Runtime System.Index
System.Runtime System.Range
System.Runtime System.Text.Rune
System.Runtime System.Text.StringRuneEnumerator
System.Runtime System.Globalization.ISOWeek
System.Runtime System.Threading.Tasks.Sources .ManualResetValueTaskSourceCore<TResult>
System.Runtime System.Runtime.Remoting.ObjectHandle
System.Runtime System.Runtime.CompilerServices .AsyncIteratorStateMachineAttribute
System.Runtime System.Runtime.CompilerServices .CallerArgumentExpressionAttribute
System.Runtime System.Collections.Generic .IAsyncEnumerable<T>
System.Runtime System.Collections.Generic .IAsyncEnumerator<T>
System.Private.CoreLib System.IAsyncDisposable
System.Private.CoreLib System.Index
System.Private.CoreLib System.Range
System.Private.CoreLib System.Text .StringBuilder+ChunkEnumerator
System.Private.CoreLib System.Text.Rune
System.Private.CoreLib System.Text.SpanRuneEnumerator
System.Private.CoreLib System.Text.StringRuneEnumerator
System.Private.CoreLib System.Globalization.ISOWeek
System.Private.CoreLib System.Buffers.OperationStatus
System.Private.CoreLib System.Buffers.StandardFormat
System.Private.CoreLib System.Buffers.Text.Utf8Formatter
System.Private.CoreLib System.Buffers.Text.Utf8Parser
System.Private.CoreLib System.Buffers.Binary.BinaryPrimitives
System.Private.CoreLib System.Threading.Tasks.Sources .ManualResetValueTaskSourceCore<TResult>
System.Private.CoreLib System.Runtime.Remoting.ObjectHandle
System.Private.CoreLib System.Runtime.Loader .AssemblyDependencyResolver
System.Private.CoreLib System.Runtime.CompilerServices .AsyncIteratorMethodBuilder
System.Private.CoreLib System.Runtime.CompilerServices .AsyncIteratorStateMachineAttribute
System.Private.CoreLib System.Runtime.CompilerServices .CallerArgumentExpressionAttribute
System.Private.CoreLib System.Runtime.CompilerServices .ConfiguredCancelableAsyncEnumerable<T>
System.Private.CoreLib System.Runtime.CompilerServices .ConfiguredCancelableAsyncEnumerable<T >+Enumerator
System.Private.CoreLib System.Runtime.Intrinsics.Vector64
System.Private.CoreLib System.Runtime.Intrinsics.Vector128
System.Private.CoreLib System.Runtime.Intrinsics.Vector256
System.Private.CoreLib System.Runtime.Intrinsics.X86.Bmi1+X64
System.Private.CoreLib System.Runtime.Intrinsics.X86.Bmi2+X64
System.Private.CoreLib System.Runtime.Intrinsics.X86.Lzcnt+X64
System.Private.CoreLib System.Runtime.Intrinsics.X86.Popcnt+X64
System.Private.CoreLib System.Runtime.Intrinsics.X86.Sse+X64
System.Private.CoreLib System.Runtime.Intrinsics.X86.Sse2+X64
System.Private.CoreLib System.Runtime.Intrinsics.X86.Sse41+X64
System.Private.CoreLib System.Runtime.Intrinsics.X86.Sse42+X64
System.Private.CoreLib System.Runtime.InteropServices .DllImportResolver
System.Private.CoreLib System.Runtime.InteropServices .NativeLibrary
System.Private.CoreLib System.Runtime.InteropServices .ComActivationContext
System.Private.CoreLib System.Runtime.InteropServices .ComActivationContextInternal
System.Private.CoreLib System.Runtime.InteropServices .ComActivator
System.Private.CoreLib System.Runtime.InteropServices .ComEventInterfaceAttribute
System.Private.CoreLib System.Runtime.InteropServices .DefaultParameterValueAttribute
System.Private.CoreLib System.Diagnostics.DebugProvider
System.Private.CoreLib System.Collections.Generic .IAsyncEnumerable<T>
System.Private.CoreLib System.Collections.Generic .IAsyncEnumerator<T>
System.Private.CoreLib Internal.Resources.PRIExceptionInfo
System.Private.CoreLib Internal.Resources .WindowsRuntimeResourceManagerBase
System.Private.CoreLib Internal.Threading.Tasks .AsyncCausalitySupport
System.Private.CoreLib Internal.Runtime.InteropServices .WindowsRuntime.ExceptionSupport
System.ObjectModel System.Reflection.ICustomTypeProvider
System.ObjectModel System.ComponentModel .TypeConverterAttribute
System.ObjectModel System.ComponentModel .TypeDescriptionProviderAttribute
System.ObjectModel System.Windows.Markup .ValueSerializerAttribute
System.Net.Sockets System.Net.Sockets.SafeSocketHandle
System.Memory System.Text.SpanRuneEnumerator
System.Memory System.Buffers.SequenceReader<T>
System.Memory System.Buffers.SequenceReaderExtensions
System System.StringNormalizationExtensions
System System.Reflection.ICustomTypeProvider
System System.Windows.Markup .ValueSerializerAttribute
System System.Runtime.InteropServices .StandardOleMarshalObject
System System.Diagnostics.ConsoleTraceListener
System System.Diagnostics .XmlWriterTraceListener
System System.Diagnostics.StackFrameExtensions
System System.Security.SecureStringMarshal
System System.Net.Sockets .SocketReceiveFromResult
System System.Net.Sockets .SocketReceiveMessageFromResult
System System.Net.Sockets.SocketTaskExtensions
System.Diagnostics.TextWriterTraceListener System.Diagnostics.ConsoleTraceListener
System.Diagnostics.TextWriterTraceListener System.Diagnostics .XmlWriterTraceListener
System.Data System.Xml.XmlDataDocument
System.Data System.Data.Common.DbColumn
System.Data System.Data.Common .DbDataReaderExtensions
System.Data System.Data.Common .IDbColumnSchemaGenerator
System.Core System.Security.Cryptography.AesCng
System.Core System.Security.Cryptography.DSACng
System.Core System.Security.Cryptography .TripleDESCng
System.Core System.Security.Cryptography.ECCurve
System.Core System.Security.Cryptography .ECParameters
System.Core System.Security.Cryptography.ECPoint
System.Core System.Security.Cryptography .IncrementalHash
System.Core System.Security.Cryptography .X509Certificates.CertificateRequest
System.Core System.Security.Cryptography .X509Certificates .DSACertificateExtensions
System.Core System.Security.Cryptography .X509Certificates .SubjectAlternativeNameBuilder
System.Core System.Security.Cryptography .X509Certificates.X509SignatureGenerator
System.ComponentModel.TypeConverter System.ComponentModel.VersionConverter
System.ComponentModel.Primitives System.ComponentModel .InvalidAsynchronousStateException
System.ComponentModel.DataAnnotations System.ComponentModel.DataAnnotations .AssociatedMetadataTypeTypeDescriptionPr ovider
System.ComponentModel.DataAnnotations System.ComponentModel.DataAnnotations .MetadataTypeAttribute
System.ComponentModel.Annotations System.ComponentModel.DataAnnotations .AssociatedMetadataTypeTypeDescriptionPr ovider
System.ComponentModel.Annotations System.ComponentModel.DataAnnotations .MetadataTypeAttribute
mscorlib System.TupleExtensions
mscorlib System.AppDomainSetup
mscorlib System.Globalization .GlobalizationExtensions
mscorlib System.Threading.ThreadPoolBoundHandle
mscorlib System.Threading.PreAllocatedOverlapped
mscorlib System.Runtime.ProfileOptimization
mscorlib System.Runtime.Remoting.ObjectHandle
mscorlib System.Runtime.CompilerServices .RuntimeFeature
mscorlib System.Runtime.CompilerServices .IsByRefLikeAttribute
mscorlib System.Runtime.CompilerServices.ITuple
mscorlib System.Runtime.CompilerServices .IsReadOnlyAttribute
mscorlib System.Runtime.CompilerServices .TupleElementNamesAttribute
mscorlib System.Runtime.CompilerServices .IDispatchConstantAttribute
mscorlib System.Runtime.InteropServices .RuntimeInformation
mscorlib System.Runtime.InteropServices .Architecture
mscorlib System.Runtime.InteropServices .OSPlatform
mscorlib System.Reflection.Emit.DynamicILInfo
mscorlib System.Security.IStackWalk
mscorlib System.Security.PermissionSet
mscorlib System.Security.Permissions .PermissionState
mscorlib System.Security.Principal .WindowsAccountType
mscorlib System.Diagnostics.Tracing .EventSourceCreatedEventArgs
Microsoft.VisualBasic Microsoft.VisualBasic.Collection
Microsoft.VisualBasic Microsoft.VisualBasic.CompareMethod
Microsoft.VisualBasic Microsoft.VisualBasic.ComClassAttribute
Microsoft.VisualBasic Microsoft.VisualBasic.ControlChars
Microsoft.VisualBasic Microsoft.VisualBasic.DateAndTime
Microsoft.VisualBasic Microsoft.VisualBasic.Information
Microsoft.VisualBasic Microsoft.VisualBasic .MyGroupCollectionAttribute
Microsoft.VisualBasic Microsoft.VisualBasic.VariantType
Microsoft.VisualBasic Microsoft.VisualBasic .VBFixedArrayAttribute
Microsoft.VisualBasic Microsoft.VisualBasic .VBFixedStringAttribute
Microsoft.VisualBasic Microsoft.VisualBasic.VBMath
Microsoft.VisualBasic Microsoft.VisualBasic.FileIO.FileSystem
Microsoft.VisualBasic Microsoft.VisualBasic.FileIO .DeleteDirectoryOption
Microsoft.VisualBasic Microsoft.VisualBasic.FileIO .RecycleOption
Microsoft.VisualBasic Microsoft.VisualBasic.FileIO .SearchOption
Microsoft.VisualBasic Microsoft.VisualBasic.FileIO .UICancelOption
Microsoft.VisualBasic Microsoft.VisualBasic.FileIO.UIOption
Microsoft.VisualBasic Microsoft.VisualBasic.FileIO .MalformedLineException
Microsoft.VisualBasic Microsoft.VisualBasic.FileIO .SpecialDirectories
Microsoft.VisualBasic Microsoft.VisualBasic.FileIO .TextFieldParser
Microsoft.VisualBasic Microsoft.VisualBasic.FileIO.FieldType
Microsoft.VisualBasic Microsoft.VisualBasic.CompilerServices .BooleanType
Microsoft.VisualBasic Microsoft.VisualBasic.CompilerServices .DecimalType
Microsoft.VisualBasic Microsoft.VisualBasic.CompilerServices .Versioned
Microsoft.VisualBasic Microsoft.VisualBasic.CompilerServices .DoubleType
Microsoft.VisualBasic Microsoft.VisualBasic .ApplicationServices.StartupEventArgs
Microsoft.VisualBasic Microsoft.VisualBasic .ApplicationServices .StartupNextInstanceEventArgs
Microsoft.VisualBasic Microsoft.VisualBasic .ApplicationServices .UnhandledExceptionEventArgs
Microsoft.VisualBasic Microsoft.VisualBasic.Devices .NetworkAvailableEventArgs
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CallType
Microsoft.VisualBasic.Core Microsoft.VisualBasic.Collection
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompareMethod
Microsoft.VisualBasic.Core Microsoft.VisualBasic.ComClassAttribute
Microsoft.VisualBasic.Core Microsoft.VisualBasic.Constants
Microsoft.VisualBasic.Core Microsoft.VisualBasic.ControlChars
Microsoft.VisualBasic.Core Microsoft.VisualBasic.DateAndTime
Microsoft.VisualBasic.Core Microsoft.VisualBasic .HideModuleNameAttribute
Microsoft.VisualBasic.Core Microsoft.VisualBasic.Information
Microsoft.VisualBasic.Core Microsoft.VisualBasic .MyGroupCollectionAttribute
Microsoft.VisualBasic.Core Microsoft.VisualBasic.Strings
Microsoft.VisualBasic.Core Microsoft.VisualBasic.VariantType
Microsoft.VisualBasic.Core Microsoft.VisualBasic .VBFixedArrayAttribute
Microsoft.VisualBasic.Core Microsoft.VisualBasic .VBFixedStringAttribute
Microsoft.VisualBasic.Core Microsoft.VisualBasic.VBMath
Microsoft.VisualBasic.Core Microsoft.VisualBasic.FileIO.FileSystem
Microsoft.VisualBasic.Core Microsoft.VisualBasic.FileIO .DeleteDirectoryOption
Microsoft.VisualBasic.Core Microsoft.VisualBasic.FileIO .RecycleOption
Microsoft.VisualBasic.Core Microsoft.VisualBasic.FileIO .SearchOption
Microsoft.VisualBasic.Core Microsoft.VisualBasic.FileIO .UICancelOption
Microsoft.VisualBasic.Core Microsoft.VisualBasic.FileIO.UIOption
Microsoft.VisualBasic.Core Microsoft.VisualBasic.FileIO .MalformedLineException
Microsoft.VisualBasic.Core Microsoft.VisualBasic.FileIO .SpecialDirectories
Microsoft.VisualBasic.Core Microsoft.VisualBasic.FileIO .TextFieldParser
Microsoft.VisualBasic.Core Microsoft.VisualBasic.FileIO.FieldType
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .BooleanType
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .Conversions
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .DecimalType
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .DesignerGeneratedAttribute
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .SiteDelegate0
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .SiteDelegate1
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .SiteDelegate2
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .SiteDelegate3
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .SiteDelegate4
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .SiteDelegate5
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .SiteDelegate6
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .SiteDelegate7
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .IncompleteInitialization
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .NewLateBinding
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .ObjectFlowControl
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .ObjectFlowControl+ForLoopControl
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .Operators
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .OptionCompareAttribute
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .OptionTextAttribute
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .ProjectData
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .StandardModuleAttribute
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .StaticLocalInitFlag
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .Utils
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .Versioned
Microsoft.VisualBasic.Core Microsoft.VisualBasic.CompilerServices .DoubleType
Microsoft.VisualBasic.Core Microsoft.VisualBasic .ApplicationServices.StartupEventArgs
Microsoft.VisualBasic.Core Microsoft.VisualBasic .ApplicationServices .StartupNextInstanceEventArgs
Microsoft.VisualBasic.Core Microsoft.VisualBasic .ApplicationServices .UnhandledExceptionEventArgs
Microsoft.VisualBasic.Core Microsoft.VisualBasic.Devices .NetworkAvailableEventArgs

NDepend and .NET Fx v4.7.2: an extension method collision and how to solve it easily

In Oct 2017 I wrote about the potential collision problem with extension methods. At that time the .NET Framework 4.7.1 was just released with this new extension method that is colliding with our own NDepend.API Append() extension method with same signature.

The problem was solved easily because just one default rule consumed our Append() extension method, we just had to refactor this method to use it as a static method call instead of an extension method call:  ExtensionMethodsEnumerable.Append(...)


Unfortunately with the recent release of .NET Framework 4.7.2, the same problem just happened again, this time with this extension method:

This time 22 default code rules are relying on our ToHashSet() extension method. This method is used widely because it is often the cornerstone to improve significantly performances. But this means that after installing the .NET Fx v4.7.2, 22 default rules will break.

This time the problem is not solved easily by calling our ExtensionMethodsSet.ToHashSet<TSource>(this IEnumerable<TSource>)  extension method as a static method because in most of these 22 rules source code, changing the extension method call into a static method call require a few brain cycle. Moreover it makes the rules source code less readable: For example the first needs to be transformed into the second:

We wanted a straightforward and clean way for NDepend users to solve this issue on all their default-or-custom code rules.  The solution is the new extension method ToHashSetEx().

Solving the issue on an existing NDepend deployment is now as simple as replacing .ToHashSet()  with  .ToHashSetEx()  in all textual files that contain the user code rules and code queries (the files with extension .ndproj and .ndrules).

We just released NDepend v2018.1.1 with this new extension method  ExtensionMethodsSet.ToHashSetEx<TSource>(this IEnumerable<TSource>). Of course all default rules and generated queries now rely on ToHashSetEx() and also a smart error message is now shown to the user in such situation:

We hesitated between ToHashSetEx() and ToHashSet2() but we are confident that this problem won’t scale (more explanation on suffixing a class or method name with Ex here).


Actually we could have detected this particular problem earlier in October 2017 because Microsoft claimed that the .NET Fx will ultimately support .NET Standard 2.0 and  .NET Standard 2.0 already presented this ToHashSet() extension method. So this time we analyzed both C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\netstandard.dll and NDepend.API.dll to double-check with this code query that there is no more risk of extension method collision:

We find back both Append() and ToHashSet() collisions and since NDepend.API is not concerned with queryable, there is no more risk of collision:



Static analysis of .NET Core 2.0 applications

NDepend v2017.3 has just been released with major improvements. One of the most requested features, now available, is the support for analyzing .NET Core 2.0 and .NET Standard 2.0 projects. .NET Core and its main flavor, ASP.NET Core, represents a major evolution for the .NET platform. Let’s have a look at how NDepend is analyzing .NET Core code.

Resolving .NET Core third party assemblies

In this post I’ll analyze the OSS application ASP.NET Core / EntityFramework MusicStore hosted on github. From the Visual Studio solution file, NDepend is resolving the application assembly MusicStore.dll and also two test assemblies that we won’t analyze here. In the screenshot below, we can see that:

  • NDepend recognizes the .NET profile, .NET Core 2.0, for this application.
  • It resolves several folders on the machine that are related to .NET Core, especially NuGet package folders.
  • It resolves all 77 third-party assemblies referenced by MusicStore.dll. This is important since many code rules and other NDepend features take into account what the application code is using.

It is worth noticing that the .NET Core platform assemblies have high granularity. A simple website like MusicStore references no fewer than 77 assemblies. This is because the .NET Core framework is implemented through a few NuGet packages that each contain many assemblies. The idea is to release the application only with needed assemblies, in order to reduce the memory footprint.

.NET Core 2.0 third party assemblies granularity

NDepend v2017.3 has a new heuristic to resolve .NET Core assemblies. This heuristic is based on .deps.json files that contain the names of the NuGet packages referenced. Here we can see that 3 NuGet packages are referenced by MusicStore. From these package names, the heuristic will resolve third-party assemblies (in the NuGet store) referenced by the application assemblies (MusicStore.dll in our case).

NuGet packages referenced in .deps.json file

Analyzing .NET Standard assemblies

Let’s be clear that NDepend v2017.3 can also analyze .NET Standard assemblies. Interestingly enough, since .NET Standard 2.0, .NET Standard assemblies reference a unique assembly named netstandard.dll and found in C:\Users\[user]\.nuget\packages\NETStandard.Library\2.0.0\build\netstandard2.0\ref\netstandard.dll.

By decompiling this assembly, we can see that it doesn’t contain any implementation, but it does contain all types that are part of .NET Standard 2.0. This makes sense if we remember that .NET Standard is not an implementation, but is a set of APIs implemented by various .NET profiles, including .NET Core 2.0, the .NET Framework v4.6.1, Mono 5.4 and more.

Browsing how the application is using .NET Core

Let’s come back to the MusicStore application that references 77 assemblies. This assembly granularity makes it impractical to browse dependencies with the dependency graph, since this generates dozens of items. We can see that NDepend suggests viewing this graph as a dependency matrix instead.

NDepend Dependency Graph on an ASP.NET Core 2.0 project

The NDepend dependency matrix can scale seamlessly on a large number of items. The numbers in the cells also provide a good hint about the represented coupling. For example, here we can see that  22 members of the assembly Microsoft.EntityFrameworkCore.dll are used by 32 methods of the assembly MusicStore.dll, and a menu lets us dig into this coupling.

NDepend Dependency Matrix on an ASP.NET Core 2.0 project

Clicking the menu item Open this dependency shows a new dependency matrix where only members involved are kept (the 32 elements in column are using the 22 elements in rows). This way you can easily dig into which part of the application is using what.

NDepend Dependency Matrix on an ASP.NET Core 2.0 project

All NDepend features now work when analyzing .NET Core

We saw how to browse the structure of a .NET Core application, but let’s underline that all NDepend features now work when analyzing .NET Core applications. On the Dashboard we can see code quality metrics related to Quality Gates, Code Rules, Issues and Technical Debt.

NDepend Dashboard on an ASP.NET Core 2.0 project

Also, most of the default code rules have been improved to avoid reporting false positives on .NET Core projects.

NDepend code rules on an ASP.NET Core 2.0 project

We hope you’ll enjoy using all your favorite NDepend features on your .NET Core projects!

NDepend version 6 insights

Welcome to the brand new NDepend blog! This blog will talk about NDepend of course, announcements, directions, features advanced usage, but this blog will also talk about related topics including, coding tricks, .NET static analysis, methodologies, theories behind features and .NET development tooling industry in general.


Choosing the right set of new features

Today I’d like to talk about the just released NDepend version 6. So far our major releases schedule followed the Microsoft Visual Studio release schedule, and Visual Studio 2015 is actually in Release Candidate period. NDepend v6 is the result of 18 months of hard work. After 11 years of development, NDepend reached a certain level of maturity. Yet there are still many new potential features and improvements possible. We found out that the most sensitive part for this version 6 was actually to chose carefully the set of new features and improvements we’d like to offer to users.  Hopefully, once version 5 was published in October 2013, we got inspiration from the Visual Studio User Voices and opened our NDepend User Voices.  As a matter of fact, version 6 new stuff reflects well the most demanded features that have just been marked as completed.

Build-Process Workflow Integration

Clearly users were asking loud for more NDepend integration into their build-process automated workflow.  So far, users were running NDepend.Console.exe, gathering the report and the information: is there any critical rule violated that should make our build fail? (this info can be obtained NDepend.Console.exe exit code). Users were asking about more information to be shown right inside their build-process tooling. There are many build-process technologies and the most demanded one were TFS, TeamCity and SonarQube. Hence we’ve collaborated with world-class experts of these technologies to deliver build-in integration. We hope that proposed integration will address most scenarios, and we are committed to support further versions and enhance the feature set.

Enhanced Visual Studio Integration

It was not surprising that users wanted more build-process integration since during the last year the bulk of our efforts were devoted to tooling for developers inside Visual Studio. NDepend was integrated in Visual Studio through the VS Addin technology because of a choice we’ve made in 2009. At that time VSIX (VS package technology) was immature and we had to support VS2008 and VS2005, hence VS Addin was the right choice. Time passing by made this initial choice less and less relevant, the VS Addin technology didn’t get any improvement from Microsoft and worth, implied a few glitches like random bug, but worth, the impossibility for VS to remember NDepend windows layout across execution. This was a pain for NDepend users and they ended up asking it loud on the User Voice to remember VS Windows Layout!

With version 6 NDepend relies on the VSIX technology to integrate in VS 2015, 2013, 2012 and 2010. (Should we mention that MS deprecated the VS Addin technology in VS 2015?). Anyway now thanks to VSIX we are able to offer a smoother and more reliable VS integration with windows layout remembering and with new features like the possibility to attach the NDepend project to a .suo file (and not only .sln file) and full support for NDepend commands keyboard-shortcut.

There were also 3 VS build featurettes proposed by various free VS extensions, and we figured out that ourselves were pretty much addicted to it. We decided to include them in the NDepend VS package, this way we will be sure to always have them at hand, and with a bit of luck, NDepend users will enjoy them too 🙂

Rule Improvements

.NET code ruling is the central feature of NDepend. We had many feedback from users about how to improve existing default code rules, mostly to reduce the number of false-positive reported. hence we’ve refactored around a third of default code rules based on their recommendations.

While doing so we figured out we have been a bit too geeky. This is great that NDepend code rules are actually editable C# LINQ queries that can contain some comments. But for many users this didn’t convey enough information about why a rule actually warns, why abiding by a specific rule will enhance their code, and how to fix a violation of the rule. Hence we’ve added the possibility to add 2 formatted texts in a NDepend rule source code comment through <Description> and <HowToFix> tags. This has been a great opportunity for us to write out about each default rule and provide users more explanations. Both in UI and in report, the user can chose to see the Description/HowToFix, or the rule C# LINQ source code.

Another need that users were asking loud in the User Voice, was the possibility to share some rule set among several NDepend projects. Typically a Company has several code bases analyzed each by a NDepend project, and what users want is a Company-level quality profile that can be applied to each code base. And taking account that NDepend makes easier than any other tool to define custom rules on .NET code, users wanted even more to define custom quality profile shareable. We addressed this need in NDepend v6 with the possibility to define rule files that can be shared among NDepend projects.

Code Metrics Visualization

NDepend already had code metrics visualization with treemaping and we decided to add coloring. The idea is that we can then visualize two code metrics, one represented by rectangle area, the other one represented by rectangle color. For example, the screenshot below shows NDepend version 6 code coverage by tests in a unique, yet convenient and accurate way.

  • Rectangles represent methods,
  • Rectangle area is proportional to # Lines of Code,
  • Rectangle color represents percentage code coverage by tests


I hope this picture helps understand why we wanted to offer users this feature. At a glance, colored treemaping can help grasp information that would be hard to get through another mean. Despite the fact NDepend v6 code base is 82%+ covered by tests, we can identify aggregation of red rectangles that shed light on regions of code not enough covered by tests. I believe no other tooling can offer such level of details, and while developing this feature, I was really looking forward what it has to say about our own coverage & testing work!

And as usual we like to make the various NDepend features interact. Hence not only you can visualize any two of the many NDepend default code metrics set, you can visualize custom code metrics defined through C# LINQ queries, and you can also highlight the result set of a code rule or a code query. Hence if we query for complex methods, we can filter complex methods match on the colored treemap:


Let’s mention that since we think that code coverage by tests is one of the most important code quality data, we also added dedicated UI candies for it in code query result:

Improvements that had to be made

A product belongs to a constantly evolving environment. This means that with years, some features that were working fine need to be revisited. Several of such needed improvements / fixes have been achieved with NDepend version 6.

Support code generated by C# and VB.NET compiler: Version after version, C# and VB.NET languages increased the amount of syntax sugar offered to the user. It started with C#2 anonymous methods and iterators, followed with C#3 lambda and anonymous types and then C#5 async support. These language constructs constraint the compiler to generate extra methods and types. And since these constructs are pretty much used, numbers of these generated elements accumulate in the IL code. And NDepend mostly relies on IL code to get code information. Hence the NDepend code model included all these generated methods and types and this started annoying the user, mostly interested by its own code. NDepend now fixes this. Simply getting rid of these generated elements was not an option because they actually contains some user code. Hence we developed some heuristics to merge these generated elements in users classes and methods that contain the code that provokes the generation by the compiler. This way there is no compromise, all the code model data is preserved, including: Code metrics (# Lines of Code, Percentage Coverage, Cyclomatic Complexity…), dependencies and diff.

Better async support: The async language construct comes with a specificity that provoked some NDepend issues. The user code is actually embedded by the compiler in a generated method that overrides the virtual method IAsyncStateMachine.MoveNext(). Hence the IL code invoking this MoveNext() generated method is bound with the interface abstract method and not with the implementation. The calls toward the async method are then lost in IL … ans so in the NDepend code model. Thanks to the heuristics wrote for the previous point, NDepend analysis is now able to track properly callers of async methods.

Support for high-DPI: Nowadays hi-resolution monitors (like 4K monitors) become affordable and as a consequence, more and more developers work with high-DPI Windows settings. High DPI means that the density of pixels is higher and as a consequence more pixels are used to represent a graphical element (text, bitmap…). The NDepend UI is mostly based on Windows Form and GDI+ and these technologies don’t scale well by default when Windows is set with high DPI. Since some users started to ping us about this problem we decided to re-lift the whole NDepend UI to make it works with DPI settings from 100% to 250%. This has been the opportunity to enhance some graphical elements and to learn some Windows Form and GDI+ high-DPI practices. I’ll try to summarize these findings in a future blog post, because browsing the web, I can see that it is a pain for many developers.

Visual Studio Theming: From our production statistics most of users consume NDepend for Developer features from within Visual Studio. So far the NDepend UI themes didn’t fit perfectly the various Visual Studio default themes, this includes Light, Dark, Blue and VS2010 default themes. Hopefully NDepend menus/bars/docking… elements are based on the DevExpress WinForm library and their latest version included these themes (and some more). Hence upgrading to the highest version of this framework did the trick.

Analysis improvements: Some improvements had to be made concerning analysis. One of them concerns resolution of assemblies to analyze. A NDepend project references a set of directories and a set of assemblies names (without file extension). At analysis-time, assemblies to analyze locations are resolved from these two sets. If multiple copies of an assembly were found, either all copies had same bits and NDepend took one of them, either some copies were different and NDepend emitted an error resolving the assembly, because we use to consider this situation as a serious deployment problem. However with time, new technologies like Windows Phone or  Portable Class Libraries appeared, and they actually provoking such situation during valid scenario. Hence, when detecting such situation, NDepend v6 now uses an heuristic to resolve the proper assembly occurrence, based on the assembly version, assemblies referenced and file size.



We are very glad to have been able to pack all these in NDepend version 6.

We hope you’ll enjoy using this new version just as much as we enjoyed making it 🙂