steps:
- powershell: |
     # test_find_program exercises some behaviour which relies on .py being in PATHEXT
     $env:PATHEXT += ';.py'

     where.exe python

     python ./skip_ci.py --base-branch-env=SYSTEM_PULLREQUEST_TARGETBRANCH --is-pull-env=SYSTEM_PULLREQUEST_PULLREQUESTID --base-branch-origin
     if ($LastExitCode -ne 0) {
        throw ('error in skip_ci.py')
     }

     # remove MinGW from path, so we don't find gfortran and try to use it
     $env:Path = ($env:Path.Split(';') | Where-Object { $_ -notlike '*mingw*' }) -join ';'

     # download and install prerequisites
     function DownloadFile([String] $Source, [String] $Destination) {
       $retries = 10
       for ($i = 1; $i -le $retries; $i++) {
           try {
               (New-Object net.webclient).DownloadFile($Source, $Destination)
               break # succeeded
           } catch [net.WebException] {
               if ($i -eq $retries) {
                   throw # fail on last retry
               }
               $backoff = (10 * $i) # backoff 10s, 20s, 30s...
               echo ('{0}: {1}' -f $Source, $_.Exception.Message)
               echo ('Retrying in {0}s...' -f $backoff)
               Start-Sleep -m ($backoff * 1000)
              }
          }
     }

     DownloadFile -Source 'https://github.com/mesonbuild/cidata/raw/master/ninja.exe' -Destination $(System.WorkFolder)\ninja.exe
     DownloadFile -Source 'http://nirbheek.in/files/binaries/pkg-config/win32/pkg-config.exe' -Destination $(System.WorkFolder)\pkg-config.exe
     DownloadFile -Source 'https://download.microsoft.com/download/D/B/B/DBB64BA1-7B51-43DB-8BF1-D1FB45EACF7A/msmpisdk.msi' -Destination msmpisdk.msi
     DownloadFile -Source 'https://download.microsoft.com/download/D/B/B/DBB64BA1-7B51-43DB-8BF1-D1FB45EACF7A/MSMpiSetup.exe' -Destination MSMpiSetup.exe
     Start-Process msiexec.exe -ArgumentList '/i msmpisdk.msi /quiet' -Wait
     Start-Process .\MSMpiSetup.exe -ArgumentList '-unattend -full' -Wait

     # import ms-mpi env vars (set by installer)
     foreach ($p in "MSMPI_INC", "MSMPI_LIB32", "MSMPI_LIB64") {
       $v = [Environment]::GetEnvironmentVariable($p, "Machine")
       Set-Content "env:$p" "$v"
     }

     # add downloads to PATH
     $env:Path = "$env:SYSTEM_WORKFOLDER;$env:Path"

     $origPath = $env:Path
     # import visual studio variables
     if ($env:compiler -eq 'msvc2015') {
       $vcvars = "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat"
     } else {
       $vcvars = "C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\VC\Auxiliary\Build\vcvarsall.bat"
     }

     ## ask cmd.exe to output the environment table after the batch file completes
     $tempFile = [IO.Path]::GetTempFileName()
     cmd /c " `"$vcvars`" $env:arch && set > `"$tempFile`" "

     ## go through the environment variables in the temp file.
     ## for each of them, set the variable in our local environment.
     Get-Content $tempFile | Foreach-Object {
       if($_ -match "^(.*?)=(.*)$") {
         Set-Content "env:\$($matches[1])" $matches[2]
       }
     }
     Remove-Item $tempFile

     if ($env:compiler -eq 'clang-cl') {
       # drop visual studio from PATH
       # (but leave INCLUDE, LIB and WindowsSdkDir environment variables set)
       $env:Path = $origPath

       # install llvm for clang-cl builds
       DownloadFile -Source 'http://releases.llvm.org/7.0.0/LLVM-7.0.0-win64.exe' -Destination LLVM-7.0.0-win64.exe
       Start-Process .\LLVM-7.0.0-win64.exe -ArgumentList '/S' -Wait
       $env:Path = "C:\Program Files\LLVM\bin;$env:Path"
       $env:CC = "clang-cl"
       $env:CXX = "clang-cl"

       # and use Windows SDK tools
       $env:Path = "$env:WindowsSdkDir\bin\$env:Arch;$env:Path"
     }

     # add .NET framework tools to path for resgen for C# tests
     # (always use 32-bit tool, as there doesn't seem to be a 64-bit tool)
     if ((Get-Command "resgen.exe" -ErrorAction SilentlyContinue) -eq $null) {
       $env:Path = "$env:WindowsSDK_ExecutablePath_x86;$env:Path"
     }

     if ($env:backend -eq 'ninja') {
       ninja --version
     } else {
       MSBuild /version
     }

     python run_tests.py --backend $(backend)

     echo "##vso[task.setvariable variable=test_status]$LastExitCode"

  continueOnError: true

- task: PublishTestResults@2
  inputs:
    testResultsFiles: meson-test-run.xml
    testRunTitle: $(System.JobName)
    publishRunAttachments: true

- task: CopyFiles@2
  inputs:
    contents: 'meson-test-run.*'
    targetFolder: $(Build.ArtifactStagingDirectory)

- task: PublishBuildArtifacts@1
  inputs:
    artifactName: $(System.JobName)
  # publishing artifacts from PRs from a fork is currently blocked
  condition: eq(variables['system.pullrequest.isfork'], false)

- powershell: |
     # after publishing test results, even if some failed
     # exit with the test status
     exit $(test_status)