I have seen quite a few build systems in my life. Most of them were very complicated with a ton of crap a lot of tools, dependencies, perl scripts, batch files, nested targets files and God knows what else. Figuring out how something worked (or, more often, why something did not work) was time consuming and very frustrating. One of the reasons for this was people were adding some stuff to the build system but no one has ever removed anything. What was even more annoying was that new dependencies oftentimes added tens of new files just to enable one small thing. Not only the enlistments were huge (how about ~200GB without QA tests?) but also configuring the machine to be able to build all this and run the tests was a sort of black magic. Because of all this I always felt bad about the fact that MSBuild did not have a Zip task available out-of-the-box. I feel that not having this one thing is the first step to having a build system that everyone hates. Yes, I know there wasn’t a Zip library in .NET Framework until now. Yes, I know there are third party Zip libraries out there. Yes, I know about MSBuild Community Tasks. Yes, I know MSBuild can somehow zip files internally as it can create VSIX files which are zip files… oops – this probably was not the best example. Anyways, not having a built-in Zip tasks means that you need to add some dependencies to your build system to be able to build your project. This will lead to a build system that no one wants to touch to not break anything. What about sharing just a single project? Like for instance my Code First view gen templates? Is it OK to tell people – “you can build it on your own – here is the project, but first you need to install this and this and this or it won’t build”? I don’t think it’s OK, but before I could not help much. Fortunately, a Zip library was finally added to .NET Framework 4.5. This allowed me creating my own Zip task. How is this task different from, for instance, the Zip task from the MSBuild community tasks? I created it as an inline task. As a resull it is just a small text file I can import to my projects. It can be checked in to my source control. It does not require any additional components being installed or present on the machine apart from what’s already there. If I need to know what the task is doing I can see the source without Reflector. I can easily change the task without having to recompile half of my build system just to be able to build what I actually want to build. (See the Disclaimer at the bottom of the page). The task looks just like this:

<UsingTask TaskName="Zip" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v4.0.dll">
    <ParameterGroup>
      <InputFileNames ParameterType="Microsoft.Build.Framework.ITaskItem[]" Required="true" />
      <OutputFileName ParameterType="System.String" Required="true" />
      <OverwriteExistingFile ParameterType="System.Boolean" Required="false" />
	</ParameterGroup>
    <Task>
      <Reference Include="System.IO.Compression" />
      <Using Namespace="System.IO.Compression" />
      <Code Type="Fragment" Language="cs">
      <![CDATA[        
        const int BufferSize = 64 * 1024;

        var buffer = new byte[BufferSize];
        var fileMode = OverwriteExistingFile ? FileMode.Create : FileMode.CreateNew;

        using (var outputFileStream = new FileStream(OutputFileName, fileMode))
        {
          using (var archive = new ZipArchive(outputFileStream, ZipArchiveMode.Create))
          {
            foreach (var inputFileName in InputFileNames.Select(f => f.ItemSpec))
            {
              var archiveEntry = archive.CreateEntry(Path.GetFileName(inputFileName));

              using (var fs = new FileStream(inputFileName, FileMode.Open))
              {
                using (var zipStream = archiveEntry.Open())
                {
                  int bytesRead = -1;
                  while ((bytesRead = fs.Read(buffer, 0, BufferSize)) > 0)
                  {
                    zipStream.Write(buffer, 0, bytesRead);
                  }
                }
              }
            }
          }
        }        
      ]]>
      </Code>
    </Task>
  </UsingTask>

Using the task is simple. Put the task to a separate file and import the file to the csproj file. In fact the file is available in my github repo – https://github.com/moozzyk/MSBuild-Tasks. Once you import the file to the project you just invoke the task as you would invoke any other task – for example (this is an actual except from one of my csproj files):

  <Import Project="common.tasks" />
  
  <Target Name="BeforeBuild">
    <ItemGroup>
      <FilesToZip Include="$(ProjectDir)\PayloadUnzipped\*.*" />
    </ItemGroup>
    <Zip 
      InputFileNames="@(FilesToZip)"
      OutputFileName="$(ProjectDir)$(TargetZipFile)"
      OverwriteExistingFile="true" />
  </Target>

That’s pretty much it. Works for me and hopefull will work for you.

Disclaimer:
I am not trying to diminish MSBuild Community Tasks or claim that inline tasks will solve all problems of this world. I am trying to say that for small simple tasks inline tasks can be just much more convenient.