Versioning build in YAML using a combination of SemVer, and days since Jan 1, 2000

SemVerAndDateIncrementing.yaml

# I use the days since Jan 1, 2000 as part of my build number to mimic a behavior found with .NET Full Framework
# that would autoincrement the 4th piece of the version information based on this math. I started using it as a
# way to reverse enginer the build date at runtime. After switching to .NET Core,I lost this, and start using this
# logic to get that behavior back
# Example build numbers resulting from this...
# 7.0.featurebranch.1+7550
# 7.0.1+7550

# Inspiration for the versioning differently between branches
# https://medium.com/@ychetankumarsarma/build-versioning-in-azure-devops-pipelines-94b5a79f80a0
# https://gist.github.com/chetanku/c51526d7322989ba5a62f186df261cd3

pool:
  vmImage: 'windows-2019'

variables:
  buildConfiguration: 'Release'
  # Manually defined Major and Minor build version
  major: 7
  minor: 0

stages:
- stage: Versioning
  displayName: Versioning
  jobs:
    
  # Build number to use when on the master branch
  - job: Build_Master_Version_Number
    displayName: Build version for Master branch
    condition: eq(variables['Build.SourceBranch'], 'refs/heads/master')
    variables:
        patch: $[counter(variables['minor'], 0)]
    steps:
      - checkout: none
      - powershell: |
          Write-Host "Generating Build Number"
          $baseDate = [datetime]"01/01/2000"
          $currentDate = $(Get-Date)
          $interval = NEW-TIMESPAN –Start $baseDate –End $currentDate
          $days = $interval.Days
          Write-Host "##vso[build.updatebuildnumber]$(major).$(minor).$(patch)+$days"

  # Slightly different build number when this is on any other branch than master
  - job: Build_Branch_Version_Number
    displayName: Build version for other branch
    condition: ne(variables['Build.SourceBranch'], 'refs/heads/master')
    variables:
        brpatch: $[counter(variables['build.sourcebranchname'], 0)]
    steps:
      - checkout: none
      - powershell: |
          Write-Host "Generating Build Number"
          $baseDate = [datetime]"01/01/2000"
          $currentDate = $(Get-Date)
          $interval = NEW-TIMESPAN –Start $baseDate –End $currentDate
          $days = $interval.Days
          Write-Host "##vso[build.updatebuildnumber]$(major).$(minor)-$(Build.SourceBranchName).$(brpatch)+$days"

# The normal tests, build, and packaging
- stage:
  dependsOn: Versioning
  displayName: Build
  jobs:
  - job:
    steps:
    - task: DotNetCoreCLI@2
      displayName: Tests
      inputs:
        command: 'test'
        projects: 'test/*[Tt]ests/*.csproj'
        arguments: '--configuration $(BuildConfiguration)'

    - task: DotNetCoreCLI@2
      displayName: Build & Package
      inputs:
        command: 'publish'
        publishWebProjects: true
        arguments: '--configuration $(BuildConfiguration) --output $(build.artifactstagingdirectory) -p:Version=$(Build.BuildNumber)'

    - task: PublishBuildArtifacts@1
      displayName: Publish Build Artifacts
      inputs:
        PathtoPublish: '$(Build.ArtifactStagingDirectory)'
        ArtifactName: 'drop'
        publishLocation: 'Container'