Regarding pre-test invocation scripts when deploying to a Test Agent with TFS

So, I learned something interesting about TFS Test Agents today and they way they handle pre-test invocation scripts when running tests on a Test Agent. In Microsoft Test Manager, do the following:

1. Connect to a Team Project
2. Change into 'Lab Center' mode
3. Click on 'Test Settings' in the top bar-ish area. This will open up the Test Settings Manager.
4. Edit or create a new 'Test Settings' item and open it up.
5. In the 'test settings' editor, under the 'Steps' column on the left-hand side, go to 'Advanced' -> 'Scripts'. You're now presented with the scripts page where you can specify scripts to be invoked before and after the execution of your test run.

Now, **here's the important thing** :

The script file(s) you specify in these boxes do not get copied to the Test Agent per se. Instead, their contents get read and merged with an automatically generated script that's created by the Test Agent. The script that actually gets run on the Test Agent will look similar to the following:

REM **************************************************************************** 

REM *  Generated by Microsoft Visual Studio 

REM *  Copyright (c) Microsoft Corporation. All rights reserved. 

REM *   

REM **************************************************************************** 

set ResultsDirectory=C:\Users\Autotest\AppData\Local\VSEQT\QTAgent\23620\00C4EF~1\Results 

set DeploymentDirectory=C:\Users\Autotest\AppData\Local\VSEQT\QTAgent\23620\00C4EF~1\DEPLOY~1 

set TestRunDirectory=C:\Users\Autotest\AppData\Local\VSEQT\QTAgent\23620\00C4EF~1 

set TestRunResultsDirectory=C:\Users\Autotest\AppData\Local\VSEQT\QTAgent\23620\00C4EF~1\Results\00C4EF~1 

set TotalAgents=1 

set AgentWeighting=100 

set AgentLoadDistributor=Microsoft.VisualStudio.TestTools.Execution.AgentLoadDistributor 

set AgentId=1 

set TestDir=C:\Users\Autotest\AppData\Local\VSEQT\QTAgent\23620\00C4EF~1 

set BuildDirectory=\\SOMESERVER\SomeShare\TFSDrops\HRST\CWSTAM~1.SPR\CWSTAM~3.1 

set DataCollectionEnvironmentContext=Microsoft.VisualStudio.TestTools.Execution.DataCollectionEnvironmentContext 

set TestLogsDir=C:\Users\Autotest\AppData\Local\VSEQT\QTAgent\23620\00C4EF~1\Results\00C4EF~1 

set ControllerName=TSTTFSTHR01:6901 

set TestDeploymentDir=C:\Users\Autotest\AppData\Local\VSEQT\QTAgent\23620\00C4EF~1\DEPLOY~1 

set AgentName=00C4EFD8-A65F-4B5E-AD5F-04F93895B543 

REM **************************************************************************** 

REM *  User Commands 

REM *   

REM **************************************************************************** 

echo "My actual user commands from my script file here"

This is important to keep in mind when you're writing the commands in the script to be executed, because no files get copied with the script file you reference in the Test Settings, and there's no mention of where that script file originally came from, so the script is effectively executed without any context except for that which is given to it by the TFS Test Agent in the prefixed lines.