How do I detect if the test run was successful in a Team Build 2013 Post-Test script?

(Updated based on more information)

The way to do this is to use environment variables and read them in your PowerShell script. Unfortunately the powershell scripts are run in a new process each time so you can't rely on the environment variables being populated.

That said, there is a workaround so you can still get those values. It involves calling a small utility at the start of your powershell script as described in this blog post: http://blogs.msmvps.com/vstsblog/2014/05/20/getting-the-compile-and-test-status-as-environment-variables-when-extending-tf-build-using-scripts/

This isn't a direct answer, but... We just set the retention policy to only keep x number of builds. If tests fail, the artifacts aren't pushed out to the next step.

With our Jenkins setup, it wipes the artifacts every new build anyway, so that isn't a problem. Only the passing builds fire the step to push the artifacts to the Octopus NuGet server.

The simplest possible way (without customizing the build template, etc.) is do something like this in your post-test script:

$testRunSucceeded = (sqlcmd -S .\sqlexpress -U sqlloginname -P passw0rd -d Tfs_DefaultCollection -Q "select State from tbl_TestRun where BuildNumber='$Env:TF_BUILD_BUILDURI'" -h-1)[0].Trim() -eq "3"

Let's pull this apart:

1. sqlcmd.exe is required; it's installed with SQL Server and is in the path by default. If you're doing builds on a machine without SQL Server, install the Command Line Utilities for SQL Server.
2. -S parameter is server + instance name of your TFS server, e.g. "sqlexpress" instance on the local machine
3. Either use a SQL login name/password combo like my example, or give the TFS build account an account on SQL Server (preferred). Grant the account read-only access to the TFS instance database.
4. The TFS instance database is named something like "Tfs_DefaultCollection".
5. The "-h-1" part at the end of the sqlcmd statement tells sqlcmd to output the results of the query without headers; the [0] selects the first result; Trim() is required to remove leading spaces; State of "3" indicates all tests passed.

Maybe someday Microsoft will publish a nice REST API that will offer access to test run/result info. Don't hold your breath though -- I've been waiting six years so far. In the meantime, hitting up the TFS DB directly is a safe and reliable way to do it.

Hope this is of some use.