altcover 8.8.21

There is a newer version of this package available.
See the version list below for details.
dotnet add package altcover --version 8.8.21                
NuGet\Install-Package altcover -Version 8.8.21                
This command is intended to be used within the Package Manager Console in Visual Studio, as it uses the NuGet module's version of Install-Package.
<PackageReference Include="altcover" Version="8.8.21" />                
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add altcover --version 8.8.21                
#r "nuget: altcover, 8.8.21"                
#r directive can be used in F# Interactive and Polyglot Notebooks. Copy this into the interactive tool or source code of the script to reference the package.
// Install altcover as a Cake Addin
#addin nuget:?package=altcover&version=8.8.21

// Install altcover as a Cake Tool
#tool nuget:?package=altcover&version=8.8.21                


Instrumenting coverage tool for .net (framework 2.0+ and core) and Mono assemblies, reimplemented and extended almost beyond recognition from dot-net-coverage, plus a set of related utilities for processing the results from this and from other programs producing similar output formats.


See the Wiki page for full details

I really want coverage for my .net core unit test project right now

Install into your test project

dotnet add package AltCover

and run

dotnet test /p:AltCover=true

The OpenCover format output will be in file coverage.xml in the project directory

What's in the box?

For Mono, .net framework and .net core, except as noted

  • AltCover, a command-line tool for recording code coverage (net472 and .netcoreapp2.0)
  • MSBuild tasks to drive the tool, including dotnet test integration
  • A PowerShell module for Windows PowerShell 5.1 and PowerShell Core 6+ containing a cmdlet that drives the tool, and other cmdlets for manipulating coverage reports
  • A coverage visualizer tool (net472) -- for .net framework, needs GTK# v2.12.xx installed separately Visualizer screenshot

Why altcover?

As the name suggests, it's an alternative coverage approach. Rather than working by hooking the .net profiling API at run-time, it works by weaving the same sort of extra IL into the assemblies of interest ahead of execution. This means that it should work pretty much everywhere, whatever your platform, so long as the executing process has write access to the results file. You can even mix-and-match between platforms used to instrument and those under test.

In particular, while instrumenting .net core assemblies "just works" with this approach, it also supports Mono, as long as suitable .mdb (or .pdb, in recent versions) symbols are available. One major limitation here is that the .mdb format only stores the start location in the source of any code sequence point, and not the end; consequently any nicely coloured reports that take that information into account may show a bit strangely.

Why altcover? -- the back-story of why it was ever a thing

Back in 2010, the new .net version finally removed the deprecated profiling APIs that the free NCover 1.5.x series relied upon. The first version of AltCover was written to both fill a gap in functionality, and to give me an excuse for a ground-up F# project to work on. As such, it saw real production use for about a year and a half, until OpenCover reached a point where it could be used for .net4/x64 work (and I could find time to adapt everything downstream that consumed NCover format input).

Fast forwards to autumn 2017, and I get the chance to dust the project off, with the intention of saying that it worked on Mono, too -- and realise that it's déja vu all over again, because .net core didn't yet have profiler based coverage tools either, and the same approach would work there as well.

Continuous Integration

Build GitHub Build statusBuild history
Test coverage Coveralls Coverage Status

Possible retirement/obsolescence of support

tl;dr -- legacy framework/Mono support is not going away any time soon.

As net472 can consume netstandard2.0 libraries (everything but the recorder), and .net core 2+ can consume net20 libraries (the recorder), legacy framework/Mono support continues until such a time as it is no longer possible to retain those API levels.

Other NuGet Packages in this suite

Product Compatible and additional computed target framework versions.
.NET net5.0 was computed.  net5.0-windows was computed.  net6.0 was computed.  net6.0-android was computed.  net6.0-ios was computed.  net6.0-maccatalyst was computed.  net6.0-macos was computed.  net6.0-tvos was computed.  net6.0-windows was computed.  net7.0 was computed.  net7.0-android was computed.  net7.0-ios was computed.  net7.0-maccatalyst was computed.  net7.0-macos was computed.  net7.0-tvos was computed.  net7.0-windows was computed.  net8.0 was computed.  net8.0-android was computed.  net8.0-browser was computed.  net8.0-ios was computed.  net8.0-maccatalyst was computed.  net8.0-macos was computed.  net8.0-tvos was computed.  net8.0-windows was computed. 
.NET Core netcoreapp2.0 was computed.  netcoreapp2.1 was computed.  netcoreapp2.2 was computed.  netcoreapp3.0 was computed.  netcoreapp3.1 was computed. 
.NET Standard netstandard2.0 is compatible.  netstandard2.1 was computed. 
.NET Framework net20 is compatible.  net35 was computed.  net40 was computed.  net403 was computed.  net45 was computed.  net451 was computed.  net452 was computed.  net46 was computed.  net461 was computed.  net462 was computed.  net463 was computed.  net47 was computed.  net471 was computed.  net472 was computed.  net48 was computed.  net481 was computed. 
MonoAndroid monoandroid was computed. 
MonoMac monomac was computed. 
MonoTouch monotouch was computed. 
Tizen tizen40 was computed.  tizen60 was computed. 
Xamarin.iOS xamarinios was computed. 
Xamarin.Mac xamarinmac was computed. 
Xamarin.TVOS xamarintvos was computed. 
Xamarin.WatchOS xamarinwatchos was computed. 
Compatible target framework(s)
Included target framework(s) (in package)
Learn more about Target Frameworks and .NET Standard.

This package has no dependencies.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories (20)

Showing the top 5 popular GitHub repositories that depend on altcover:

Repository Stars
A cross-platform .NET library for IMAP, POP3, and SMTP.
Simple, powerful, cross-platform SQLite client and ORM for .NET
A simple package with guard clause extensions.
ReportGenerator converts coverage reports generated by coverlet, OpenCover, dotCover, Visual Studio, NCover, Cobertura, JaCoCo, Clover, gcov or lcov into human readable reports in various formats.
A .NET MIME creation and parser library with support for S/MIME, PGP, DKIM, TNEF and Unix mbox spools.
Version Downloads Last updated
8.8.74 20,802 5/31/2024
8.8.53 8,696 5/16/2024
8.8.21 24,797 4/15/2024
8.8.10 7,878 4/6/2024
8.7.3 22,396 3/14/2024
8.6.125 62,234 1/4/2024
8.6.95 24,371 11/14/2023
8.6.68 122,838 7/10/2023
8.6.61 25,496 6/6/2023
8.6.45 79,327 3/21/2023
8.6.40 12,697 3/16/2023
8.6.14 112,549 1/1/2023
8.5.842 12,040 12/25/2022
8.5.841 30,511 11/19/2022
8.4.840 50,869 10/17/2022
8.3.839 24,617 9/13/2022

This build from

Q. Never mind the fluff -- how do I get started?
A. Start with the Quick Start guide : and
read the FAQ :

8.8.21 (Habu series release 28)
• [BREAKING; BUGFIX] Issue #206 : Update to net6+ for dotnet test integration and respect the $(IsTestProject) setting from the Microsoft.NET.Test.Sdk package.
• Simplify the use of the AltCover MSBuild tasks via the associated package-level .targets file by not even including the VSTest integration unless both '$(AltCover)' == 'true' AND '$(IsTestProject)' == 'true'.
• Mitigate instances of System.IO.IOException: The process cannot access the file '[coverage report]' because it is being used by another process.
• Explicitly add GAC locations to the paths inspected for dependency resolution

8.8.10 (Habu series release 27)
• [BUGFIX] Add Json member to the report format enumerations for the typesafe API and for the InvokeAltCover cmdlet.
• [BUGFIX] Issue #214 : patch Mono.Cecil to use FIPS compliant algorithm
• [Enhancement] Discussion #206, maybe also Issue #203 : Option --portable and equivalent APIs to place the coverage report file and related coverage data in the same folder as the recorder assembly, wherever that might be, allowing the whole instrumented folder structure to be moved into another file structure (e.g. different machine, different OS).

8.7.3 (Habu series release 26)
• [Enhancement] Discussion 202 : More careful tidying of temporary .runsettings files, fixing long-standing errors of both commission and omission.
• [Enhancement] Discussion 199 : Add /p:AltCoverOutputRoot=[path] and associated APIs for dotnet test command line creation.  The [path] is a directory to be used instead of $(TargetDir) for the relative placing of the instrumented or saved files.  The use-case here is when $(TargetDir) is close to MAX_PATH and the generated sub-folders would overflow that limit.

For previous releases (8.6.125 and earlier) go here --