FirstJobWaitForOthers.ps1

if ($env:APPVEYOR_JOB_NUMBER -ne 1) {return}

write-host "Waiting for other jobs to complete"

$headers = @{
  "Authorization" = "Bearer $ApiKey"
  "Content-type" = "application/json"
}

[datetime]$stop = ([datetime]::Now).AddMinutes($env:TimeOutMins)
[bool]$success = $false

while(!$success -and ([datetime]::Now) -lt $stop) {
    $project = Invoke-RestMethod -Uri "https://ci.appveyor.com/api/projects/$env:APPVEYOR_ACCOUNT_NAME/$env:APPVEYOR_PROJECT_SLUG" -Headers $headers -Method GET
    $success = $true  
    $project.build.jobs | foreach-object {if (($_.jobId -ne $env:APPVEYOR_JOB_ID) -and ($_.status -ne "success")) {$success = $false}; $_.jobId; $_.status}
    if (!$success) {Start-sleep 5}
}

if (!$success) {throw "Test jobs were not finished in $env:TimeOutMins minutes"}

function Get-AppVeyorBuild {
    param()

    if (-not ($env:APPVEYOR_API_TOKEN)) {
        throw "missing api token for AppVeyor."
    }
    if (-not ($env:APPVEYOR_ACCOUNT_NAME)) {
        throw "not an appveyor build."
    }

    Invoke-RestMethod -Uri "https://ci.appveyor.com/api/projects/$env:APPVEYOR_ACCOUNT_NAME/$env:APPVEYOR_PROJECT_SLUG" -Method GET -Headers @{
        "Authorization" = "Bearer $env:APPVEYOR_API_TOKEN"
        "Content-type"  = "application/json"
    }
}
function allJobsFinished {
    param()
    $buildData = Get-AppVeyorBuild
    $lastJob = ($buildData.build.jobs | Select-Object -Last 1).jobId

    if ($lastJob -ne $env:APPVEYOR_JOB_ID) {
        return $false
    }

    write-host "Waiting for other jobs to complete"

    [datetime]$stop = ([datetime]::Now).AddMinutes($env:TimeOutMins)

    do {
        (Get-AppVeyorBuild).build.jobs | Where-Object {$_.jobId -ne $env:APPVEYOR_JOB_ID} | Foreach-Object `
            -Begin { $continue = @() } `
            -Progress {
                $job = $_
                switch ($job.status) {
                    "failed" { throw "AppVeyor's Job ($($job.jobId)) failed." }
                    "success" { $continue += $true; continue }
                    Default { $continue += $false; Write-Host "new state: $_.status" }
                }
            } `
            -End { if ($false -notin $continue) { return $true } }
        Start-sleep 5
    } while (([datetime]::Now) -lt $stop)

    throw "Test jobs were not finished in $env:TimeOutMins minutes"
}

How would I use this to make a deploy step conditional in the YML?

Would I make it set an environment variable of some sort, and make the deploy conditional on the environment variable?

Could you show me an example?

@jezzsantos sorry missed this question. Please check conditional deployment

This doesn't work if you've got two builds running at the same time. Only the most recent build is ever returned. So, it doesn't work if you're doing a branch build and a PR build at the same time.

I would expect the https://ci.appveyor.com/api/projects/$env:APPVEYOR_ACCOUNT_NAME/$env:APPVEYOR_PROJECT_SLUG endpoint to return all running builds, but it only returns the one with the highest build number. :(