Set-ProjectVersion for AppVeyor

Set-ProjectVersion.psm1

<# 
 .Synopsis
  Updates project.json version

 .Description
  Updates the project.json version to include the build number as pre-release suffix.
  If the current build is a tag, the the build number is *NOT* appended.

 .Parameter Path
  The path to the project.json file.

 .Parameter SetAppveyorVersion  
  Flag that indicates whether the script should also set the AppVeyor version number.

 .Returns
  The determined build number.

 .Example
   > Set-ProjectVersion -path "src\MyApp\project.json"
   > 1.0.0

 .Example
   > Set-ProjectVersion -path "src\MyApp\project.json" -setAppveyorVersion
   > 1.0.0-ci321
#>
function Set-ProjectVersion {
param(
	[string] $path,
	[switch] $setAppveyorVersion = $false
)
	$str = Get-Content -Raw -Path $path
	$json = ConvertFrom-Json $str
	
	$version = $buildVersion = $json.version

	if ($env:APPVEYOR_REPO_TAG -eq $false) {
		$buildVersion = "$version-ci$($env:APPVEYOR_BUILD_NUMBER)"
		$str.Replace("""version"": ""$version"",", """version"": ""$buildVersion"",") | Set-Content $path
	}
	
	if ($setAppveyorVersion -eq $true) {
		Update-AppveyorBuild -Version $buildVersion
	}

	return $buildVersion
}

Export-ModuleMember -Function Set-ProjectVersion