Why Write Automated Tests?

Now that we know what automated testing is, it's worth discussing why we would spend time writing (and maintaining) a test suite.

Money

At the end of the day, everything boils down to money.

Customers expect a working product, and given enough frustrating experiences, may switch to a different piece of software if what we've built doesn't behave correctly.

Our teammates expect to work in a codebase that operates as intended, with the confidence that what they (and their teammates) have developed can be modified or extended as needs change without breaking what exists.

Stakeholders expect development velocity to remain high with a nimble team, even as the surface area of the application grows.

Confidence

Automated tests provide the confidence that the application will continue to work, because if it doesn't in certain situations, the test suite should fail and notify the team.