Your build and test scripts deserve first class treatment.
Some people treat the build and test scripts as second-hand citizens, which is a mistake. These scripts are a critical part of the process that builds your product. They may not be a part of the finished product that is seen by the customer, but they are still vital to delivering a high-quality product.
Maintain these scripts in version control. You’ll want to be able to revert to earlier versions if something goes wrong, or if recent changes don’t give you the results you want.
Similarly, track changes. Just as you would open a ticket in your issue tracking system for software enhancement, you should also open tickets for changes to build and test scripts.
Follow best practices when writing your scripts. This means choosing your names carefully, adding proper documentation, separating concerns, and avoiding copypasta code.
In other words, don’t do things in your scripts that wouldn’t do in your source code. They’re just as important.