Using Powershell's Invoke-WebRequest to persist state between requests using SessionVariable

by Frank Fu

Recently, I've been testing ASP.NET MVC's Output Cache feature and wanted to test using different parameters such as VaryByCustom which would read a user's cookies and construct a cache key according to some value.

I ended up having to log in and out of Google Chrome, Firefox, Edge etc just to test this so I created a script to do so instead.

$loginUrl = "https://example.com/log-in"
$normalUrl = "https://example.com/logged-in-area"

$postParams = @{email='foo@bar.com';password='1234'}
iwr -Uri $url  -Method POST -Body $postParams -SessionVariable MySessionVariable
iwr $normalUrl -WebSession $MySessionVariable

# Optionally view what cookies got stored
$MySessionVariable.Cookies.GetCookies($url)

The magic lies in the MySessionVariable variable which is basically a Cookie object that gets passed in each invocation.