Demo of using Git branch with mapping + commit count to set version properties in csproj

GitVersionedProject.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>netcoreapp1.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <GitBranchToReleaseLabelMapping Include="master" ReleaseLabel="rtm" />
    <GitBranchToReleaseLabelMapping Include="develop" ReleaseLabel="beta" />
  </ItemGroup>

  <!--
    ========================================================================================================================
                                                    CreateGitVersionSuffix
    
    Hooks before PrepareForBuild target to read git metadata to update VersionSuffix, Version and PackageVersion accordingly.

    Parameters:
       (Examples are based on VersionPrefix == '1.0.0' and commit nr. 23 on branch 'master')

    UseCompatGitVersion (default: true): 
        Set to 'false' to use Semver 2.0.0 separation of release labels.
        This will trigger a NuGet warning on build saying that the version will not be supported on legacy NuGet clients,
        but if you want true SemVer 2.0.0 versions, this is your option.

        With UseCompatGitVersion == 'true' (default):
        1.0.0-master-0000023
        With UseCompatGitVersion == 'false':
        1.0.0-master.23

    IncludeBranchInGitVersion:
        Set to 'false' to omit adding the branch name to the version.

        With IncludeBranchInGitVersion == 'true' (default):
        1.0.0-master-0000023
        With IncludeBranchInGitVersion == 'false':
        1.0.0-0000023

    VersionSuffix:
        Any preexisting version suffix will be considered and the git information will be added to it:

        With VersionSuffix == 'alpha':
          * And IncludeBranchInGitVersion == 'true' (default):
            1.0.0-alpha-master-0000023
          * And IncludeBranchInGitVersion == 'false':
            1.0.0-alpha-0000023
    
    Items:

    GitBranchToReleaseLabelMapping:
        The target will respect 'GitBranchToReleaseLabelMapping' items to map known branches to release labels.
        This is useful if you don't want the branch names to end up in the verions, but specific names for specific branches.
        (Think of it as a branch name replacement dictionary).

        Example: Project contains:
          <ItemGroup>
            <GitBranchToReleaseLabelMapping Include="master" ReleaseLabel="rc" />
            <GitBranchToReleaseLabelMapping Include="develop" ReleaseLabel="beta" />
          </ItemGroup>
        
        When built from the master branch, will result in version:
          1.0.0-rc-0000023

    Outputs / Properties Set:

    GitBranchName:
        Will contain the current branch name - e.g. 'master' or 'feature/awesome'
    GitBranchNameSanitized:
        Will contain the branch name having slashes been replaced with underscores so that the name can be used for versioning.
        (Note: SemVer would require more sanitizing but slashes are the most important blockers.
               Just don't use emojis in a branch name..)
    
    GitCommitCount:
        Contians the number of commits on the current branch. Can be used for SemVer 2.0.0 versioning.
    GitCommitCountPadded:
        Same as GitCommitCount, but extended to 7 characters with leading zeros. This is needed for
        SemVer 1.0.0 compatible versioning which is purely alphanumeric and doesn't support multiple lables.
        See the examples for UseCompatGitVersion.

    GitVersionInfo:
        Contains all relevant parts of branch / commit count info that will be used for versoining.
    
    GitVersionPrefix:
        What the target will use to calculate the prefix part of the Version property. Defaults to VersionPrefix if not Set
        or will default to Version if no VersionPrefix is defined. This may only be useful if a full Version is specified.
        E.g. having Version == '1.0.0-rc1' without VersionPrefix or VersionSuffix being defined will still result in a
        working version: '1.0.0-rc1-master-0000023'

    Version:
        The Version property will be updated with appended git infos.
    PackageVersion:
        Will be set to Version so that git status will also affect the version of generated nuget packages.
 
    ========================================================================================================================
    -->
  <Target Name="CreateGitVersionSuffix" BeforeTargets="PrepareForBuild">
    <Error Text="GitBranchToReleaseLabelMapping item '%(GitBranchToReleaseLabelMapping.Identity)' does not have a ReleaseLabel metadata"
           Condition=" '%(GitBranchToReleaseLabelMapping.ReleaseLabel)' == '' " />

    <Exec Command="git rev-parse --abbrev-ref HEAD" ConsoleToMSBuild="true" StandardOutputImportance="low">
      <Output TaskParameter="ConsoleOutput" PropertyName="GitBranchName" />
    </Exec>

    <Exec Command="git rev-list --count HEAD" ConsoleToMSBuild="true" StandardOutputImportance="low">
      <Output TaskParameter="ConsoleOutput" PropertyName="GitCommitCount" />
    </Exec>

    <PropertyGroup>
      <GitBranchNameSanitized>$(GitBranchName.Replace('/','-'))</GitBranchNameSanitized>
      <GitCommitCountPadded>$([System.Int32]::Parse('$(GitCommitCount)').ToString('D7'))</GitCommitCountPadded>

      <UseCompatGitVersion Condition=" '$(UseCompatGitVersion)' == '' ">true</UseCompatGitVersion>

      <_GitBranchReleaseLabel Condition=" '%(GitBranchToReleaseLabelMapping.Identity)' == '$(GitBranchName)' ">%(GitBranchToReleaseLabelMapping.ReleaseLabel)</_GitBranchReleaseLabel>
      <_GitBranchReleaseLabel Condition=" '$(_GitBranchReleaseLabel)' == '' ">$(GitBranchNameSanitized)</_GitBranchReleaseLabel>

      <_GitCommitCountInVersion Condition=" '$(_GitCommitCountInVersion)' == '' and '$(UseCompatGitVersion)' == 'true' ">$(GitCommitCountPadded)</_GitCommitCountInVersion>
      <_GitCommitCountInVersion Condition=" '$(_GitCommitCountInVersion)' == '' ">$(GitCommitCount)</_GitCommitCountInVersion>

      <_GitVersionPartSeparator Condition=" '$(_GitVersionPartSeparator)' == '' and '$(UseCompatGitVersion)' == 'true' ">-</_GitVersionPartSeparator>
      <_GitVersionPartSeparator Condition=" '$(_GitVersionPartSeparator)' == '' ">.</_GitVersionPartSeparator>

      <GitVersionInfo Condition=" '$(GitVersionInfo)' == '' and '$(IncludeBranchInGitVersion)' == 'false' ">$(_GitCommitCountInVersion)</GitVersionInfo>
      <GitVersionInfo Condition=" '$(GitVersionInfo)' == '' ">$(_GitBranchReleaseLabel)$(_GitVersionPartSeparator)$(_GitCommitCountInVersion)</GitVersionInfo>

      <VersionSuffix Condition=" '$(VersionSuffix)' != '' ">$(VersionSuffix)$(_GitVersionPartSeparator)$(GitVersionInfo)</VersionSuffix>
      <VersionSuffix Condition=" '$(VersionSuffix)' == '' ">$(GitVersionInfo)</VersionSuffix>

      <GitVersionPrefix Condition=" '$(GitVersionPrefix)' == '' and '$(VersionPrefix)' == '' ">$(Version)</GitVersionPrefix>
      <GitVersionPrefix Condition=" '$(GitVersionPrefix)' == '' ">$(VersionPrefix)</GitVersionPrefix>

      <Version>$(GitVersionPrefix)-$(VersionSuffix)</Version>
      <PackageVersion>$(Version)</PackageVersion>
    </PropertyGroup>
  </Target>

</Project>