PowerShell script to re-download published TRX files after VSTest / VsTestForSpecSync task see https://docs.specsolutions.eu/specsync/important-concepts/how-to-publish-test-results-from-pipelines-using-the-vstest-task for details.

download-trx-from-testrun.ps1

[CmdletBinding()]
param (
  $outputFolder = "TestResults",
  $testRunId = $env:VSTEST_TESTRUNID,
  $pat = $env:SYSTEM_ACCESSTOKEN,
  $projectUrl = $env:SYSTEM_COLLECTIONURI + $env:SYSTEM_TEAMPROJECT
)

if ($testRunId -eq $null -or $testRunId -eq '') {
    Write-Error 'Test Run ID is not specified!' -ErrorAction Stop
}
if ($pat -eq $null -or $pat -eq '') {
    Write-Error 'PAT is not specified!' -ErrorAction Stop
}
if ($projectUrl -eq $null -or $projectUrl -eq '') {
    Write-Error 'Project URL is not specified!' -ErrorAction Stop
}
if ($outputFolder -eq $null -or $outputFolder -eq '') {
    Write-Error 'Output folder is not specified!' -ErrorAction Stop
}

Write-Host "Downloading attachments for Test Run #$testRunId in project $projectUrl"

$currentFolder = Get-Location
$fullOutputFolder = [System.IO.Path]::GetFullPath([System.IO.Path]::Combine($currentFolder, $outputFolder))
$_ = [System.IO.Directory]::CreateDirectory($fullOutputFolder)

$token = [System.Convert]::ToBase64String([System.Text.Encoding]::ASCII.GetBytes(":$($pat)"))
$header = @{Authorization = "Basic $token"}

$attachmentsResult = Invoke-RestMethod -Uri ("$projectUrl/_apis/test/runs/" + $testRunId + "/attachments?api-version=5.1") -Headers $header -Method Get

Write-Debug "attachments = $($attachmentsResult | ConvertTo-Json -Depth 100)"

$attachmentsResult.value | ForEach-Object {
    $attachmentUrl = $_.url
    $attachmentFileName = $_.fileName
    $outputFile = [System.IO.Path]::Combine($fullOutputFolder, $attachmentFileName)
    Write-Host "Downloading attachment $attachmentFileName"
    Write-Host "  from $attachmentUrl"
    Write-Host "  to $outputFile"
    Invoke-RestMethod -Uri ($attachmentUrl + "?api-version=5.1") -Headers $header -Method Get -OutFile $outputFile
}