eng/scripts/ChangedFiles-Functions.ps1

function Get-ChangedFiles($baseCommitish = "HEAD^", $targetCommitish = "HEAD", $diffFilter = "d") {
  # diff-filter=d is to exclude any deleted files as we don't generally 
  # want to do work against files that no longer exist.
  # https://git-scm.com/docs/git-diff#Documentation/git-diff.txt---diff-filterACDMRTUXB82308203

  # core.quotepath=off is to help avoid quoting in the returned paths
  # https://git-scm.com/docs/git-config/2.22.0#Documentation/git-config.txt-corequotePath

  # Get all the files that have changed between HEAD and the commit before head
  # For PR's that last commit is always a merge commit so HEAD^ will get the parent
  # commit of the base branch and as such will diff HEAD against HEAD^
  $changedFiles = git -c core.quotepath=off diff --name-only --diff-filter=$diffFilter $baseCommitish $targetCommitish
  $changedFiles = $changedFiles | Where-Object { !$_.Contains("ChangedFiles-Functions") }

  Write-Verbose "Changed files:"
  $changedFiles | ForEach-Object { Write-Verbose "$_" }

  return $changedFiles
}

function Get-ChangedSwaggerFiles($changedFiles = (Get-ChangedFiles)) {
  $changedFiles = Get-ChangedFilesUnderSpecification $changedFiles

  $changedSwaggerFiles = $changedFiles.Where({ 
    $_.EndsWith(".json")
  })
    
  return $changedSwaggerFiles
}

function Get-ChangedFilesUnderSpecification($changedFiles = (Get-ChangedFiles)) {
  $changedFilesUnderSpecification = $changedFiles.Where({ 
    $_.StartsWith("specification")
  })
    
  return $changedFilesUnderSpecification
}

function Get-ChangedCoreFiles($changedFiles = (Get-ChangedFiles)) {
  $rootFiles = @(
    ".gitattributes",
    ".prettierrc.json",
    "package-lock.json",
    "package.json",
    "tsconfig.json",
    "specification/suppressions.yaml"
  )

  $coreFiles = $changedFiles.Where({ 
    $_.StartsWith(".github/") -or
    $_.StartsWith("eng/") -or
    $_.StartsWith("specification/common-types/") -or
    $_ -in $rootFiles
  })

  return $coreFiles
}