Migrate Redmine issues to Visual Studio Team Services work items

CreateVSTSItems.ps1

param(
    $user, # "VSTS username - doesn't need @domain suffix"
    $token, # VSTS personal access token
    $project, # the VSTS project to create items in
    $vstsAccountName, # the bit before .visualstudio.com
    $csvFile, # path to the .csv file
    $redmineIssueUrl # URL to legacy redmine server. eg. https://redmine/issues
)

$ErrorActionPreference = "Stop"

$base64AuthInfo = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(("{0}:{1}" -f $user,$token)))

$headers = @{Authorization=("Basic {0}" -f $base64AuthInfo)}

# Get users (if you need to map between usernames)
# $result=Invoke-RestMethod -Method GET -Uri "https://$($vstsAccountName).vsaex.visualstudio.com/_apis/userentitlements?api-version=5.0-preview.1" -Headers $headers
#
# $userMap = @{
# }
#
# $result.value | ForEach-Object {
#     $userMap.Add($_.user.displayName, $_.user.displayName)
# }

$priorityMap = @{
    'High' = '1'
    'Normal' = '2'
    'Low' = '3'
}

$data = Import-Csv -Path $csvFile

foreach ($item in $data) {

    switch ($item.Tracker) {
        "Bug" { 
            $workItemType = "Bug"
            $descriptionField = "Microsoft.VSTS.TCM.ReproSteps"
        }
        "Enhancement" { 
            $workItemType = "Product Backlog Item" 
            $descriptionField = "System.Description"
        }
        "Feature" { 
            $workItemType = "Product Backlog Item" 
            $descriptionField = "System.Description"
        }
        Default {
            Write-Warning "Skipping $($item.Tracker)"
            continue;
        }
    }

    $bodyArray = @(
        @{
            op    = "add"
            path  = "/fields/System.Title"
            value = $item.Subject
        }
        @{
            op    = "add"
            path  = "/fields/$descriptionField"
            value = $item.Description
        }
        @{
            op    = "add"
            path  = "/fields/Microsoft.VSTS.Common.Priority"
            value = $priorityMap[$item.Priority]
        }
        @{
            op    = "add"
            path  = "/relations/-"
            value = @{
                rel = "Hyperlink"
                url = "$($redmineIssueUrl)/$($item.ID)"
                attributes = @{
                    comment = "Link to original ticket"
                }
            }
        }
    )

    if ($item.Assignee -ne "") {
        $bodyArray += @{
            op    = "add"
            path  = "/fields/System.AssignedTo"
            value = $item.Assignee
        }
    }
    
    $body = $bodyArray | ConvertTo-Json -Depth 3

    $result=Invoke-RestMethod -Method PATCH -Uri "https://$($vstsAccountName).visualstudio.com/$($project)/_apis/wit/workitems/`$$($workItemType)?api-version=5.0-preview.3" -Headers $headers -ContentType "application/json-patch+json" -Body $body

    Write-Host "Created item $($result.id) from legacy ticket $($item.ID)"
}

I've made a more extended version to migrate issue from redmine: https://github.com/wpoely86/redmine-azure-devops-migrate