CalculateNewPreviewVersion.ps1

Param(
 [string]$owner,
 [string]$repo,
 [string]$previewStr
)

Write-Host"Calculating new Preview Version:"-ForegroundColor Magenta;

$newVersionStr;

$releasesUrl="https://api.github.com/repos/$($owner)/$($repo)/releases";

Write-Host"Getting list of releases with '$($releasesUrl)'"-ForegroundColor Blue;
$releasesJSON=Invoke-RestMethod-Uri $releasesUrl-Method Get;

if ($releasesJSON.Count-eq0) {
Write-Host"Unable to get releases list with '$($releasesUrl)'"-ForegroundColor Red;
Write-Host"NOTE: This Script cannot handle the first release"-ForegroundColor Cyan;
EXIT1;
}

$lastReleaseJSON=$releasesJSON[0]; 
$lastReleaseVersionStr=$lastReleaseJSON.tag_name;
$isPreRelease=$lastReleaseJSON.prerelease;

if ([string]::IsNullOrEmpty($lastReleaseVersionStr)) {
Write-Host"Unable read the last release tag name"-ForegroundColor Red;
Write-Host"Last Release Data:"-ForegroundColor Cyan;
Write-Host-Object $lastReleaseJSON-ForegroundColor Cyan;
EXIT1;
}

if ([string]::IsNullOrEmpty($isPreRelease)) {
Write-Host"Unable read the last release is pre-release or not"-ForegroundColor Red;
Write-Host"Last Release Data:"-ForegroundColor Cyan;
Write-Host-Object $lastReleaseJSON-ForegroundColor Cyan;
EXIT1;
}

$isPreRelease=$isPreRelease-as [bool];
$versionArr=$lastReleaseVersionStr.split(".");
if ($isPreRelease) {
if (!$versionArr[2].Contains("-$($previewStr)")) {
Write-Host"Lastest release '$($lastReleaseVersionStr)' is mentioned as pre-release but '$($previewStr)' is missing in version string"-ForegroundColor Red;
Write-Host"Last Release Data:"-ForegroundColor Cyan;
Write-Host-Object $lastReleaseJSON-ForegroundColor Cyan;
EXIT1;
 }
$previewVersionStr=$versionArr[$versionArr.Count-1];
$previewVersion=$previewVersionStr-as [int];
$newPreviewVersion=$previewVersion+1;
$versionArr[$versionArr.Count-1] =$newPreviewVersion;
$newVersionStr=$versionArr-join".";
Write-Host"Current version is '$($lastReleaseVersionStr)'"-ForegroundColor Blue;
Write-Host"New calculated version is '$($newVersionStr)'"-ForegroundColor Green;
}
else {
if ($versionArr[2].Contains("-$($previewStr)")) {
Write-Host"Lastest release '$($lastReleaseVersionStr)' is mentioned as production release but version string has '$($previewStr)'"-ForegroundColor Red;
Write-Host"Last Release Data:"-ForegroundColor Cyan;
Write-Host-Object $lastReleaseJSON-ForegroundColor Cyan;
EXIT1;
 }
$minorVersionStr=$versionArr[1];
$minorVersion=$minorVersionStr-as [int];
$newMinorVersion=$minorVersion+1;
$newPatchVersion=0;
$newPreviewVersion=1;
$versionArr[1] =$newMinorVersion;
$versionArr[2] ="$($newPatchVersion)-$($previewStr).$($newPreviewVersion)";
$newVersionStr=$versionArr-join".";
Write-Host"Current version is '$($lastReleaseVersionStr)'"-ForegroundColor Blue;
Write-Host"New calculated version is '$($newVersionStr)'"-ForegroundColor Green;
}

Write-Host"##vso[task.setvariable variable=NEW_VERSION_STRING]$($newVersionStr)";

Write-Host"Updated new version in global variable"-ForegroundColor Green;