try {
 $user = 'admin'
 $pass = 'password'

 $pair = "$($user):$($pass)"
 $encodedCreds = [System.Convert]::ToBase64String([System.Text.Encoding]::ASCII.GetBytes($pair))
 $basicAuthValue = "Basic $encodedCreds"
 $multipartContent = New-Object System.Net.Http.MultipartFormDataContent
 $multipartFile = "junit.xml"
 $FsMode = [System.IO.FileMode]::Open
 $FsAccess = [System.IO.FileAccess]::Read
 $FsSharing = [System.IO.FileShare]::Read
 $FileStream = New-Object System.IO.FileStream($multipartFile, $FsMode, $FsAccess, $FsSharing)
 $fileHeader = New-Object System.Net.Http.Headers.ContentDispositionHeaderValue("form-data")
 $fileHeader.Name = "file"
 $fileHeader.FileName = 'junit.xml'
 $fileContent = New-Object System.Net.Http.StreamContent($FileStream)
 $fileContent.Headers.ContentDisposition = $fileHeader
 $fileContent.Headers.ContentType = [System.Net.Http.Headers.MediaTypeHeaderValue]::Parse("text/xml")
 $multipartContent.Add($fileContent)
 $uri = 'http://yourjiraserver/rest/raven/1.0/import/execution/junit?projectKey=CALC'
 $res = Invoke-WebRequest -Uri $uri -Body $multipartContent -Method POST -Headers @{"Authorization" = $basicAuthValue} }
catch {     
write-host $_.Exception.Message
}