BuildRDLFiles.yml

stages:
- stage: Build
  jobs:
  - job: Build
    pool: 
      name: 'SelfHostedPool'
    steps:
    # Download previous artifacts (if any)
    - task: DownloadBuildArtifacts@1
      displayName: 'Download previous manifest'
      inputs:
        buildType: 'specific'
        project: '$(System.TeamProject)'
        definition: '$(Build.DefinitionName)'
        buildVersionToDownload: 'latestFromBranch'
        branchName: 'refs/heads/main'
        downloadPath: '$(Pipeline.Workspace)\previous'
      continueOnError: true   # first build won't have old manifest

    # Compare + prepare changed RDLs
    - task: PowerShell@2
      displayName: 'Compare RDLs and prepare artifacts'
      inputs:
        targetType: inline
        script: |
          $rdlFolder = "$(Build.SourcesDirectory)\reports"
          $artifactDir = "$(Build.ArtifactStagingDirectory)"
          New-Item -ItemType Directory -Force -Path $artifactDir | Out-Null
          
          # script block from above (compute hash + compare + copy)
          $rdlFolder = "$(Build.SourcesDirectory)\reports"
          $artifactDir = "$(Build.ArtifactStagingDirectory)"
          $newManifestPath = Join-Path $artifactDir "rdl-manifest.json"

          $newHashes = @()
          Get-ChildItem -Path $rdlFolder -Filter *.rdl -File -Recurse | ForEach-Object {
              $hash = Get-FileHash -Algorithm SHA256 -Path $_.FullName
              $newHashes += [PSCustomObject]@{
                  FileName = $_.Name
                  RelativePath = $_.FullName.Substring($rdlFolder.Length+1)
                  Hash = $hash.Hash
                  FullPath = $_.FullName
              }
          }

          $oldManifestPath = "$(Pipeline.Workspace)\previous\rdl\rdl-manifest.json"
          $oldHashes = @()
          if (Test-Path $oldManifestPath) {
              $oldHashes = Get-Content $oldManifestPath | ConvertFrom-Json
          }

          $changed = @()
          foreach ($n in $newHashes) {
              $match = $oldHashes | Where-Object { $_.FileName -eq $n.FileName }
              if (-not $match) {
                  Write-Host "NEW report: $($n.FileName)"
                  $changed += $n
              }
              elseif ($match.Hash -ne $n.Hash) {
                  Write-Host "CHANGED report: $($n.FileName)"
                  $changed += $n
              }
              else {
                  Write-Host "UNCHANGED report: $($n.FileName)"
              }
          }

          foreach ($c in $changed) {
              $targetPath = Join-Path $artifactDir $c.FileName
              Copy-Item $c.FullPath $targetPath -Force
          }

          $newHashes | ConvertTo-Json -Depth 3 | Out-File $newManifestPath

    - task: PublishBuildArtifacts@1
      displayName: 'Publish changed RDLs'
      inputs:
        PathtoPublish: '$(Build.ArtifactStagingDirectory)'
        ArtifactName: 'rdl'