[farley13]

Not to pick on you specifically, but I tend to agree with other posters that testing (automated or otherwise) is just an element of programming. Like all elements it needs to be done to taste, but it's pretty essential.

A line of questioning: Do you have time to write clear code? Time for comments? Time to manually test your changes hundreds of times? Time to refactor existing code when adding new code? Time to remove dead code? Time to automate the testing while you still have the little state machine you are working on in your head? Time to add observability to spot performance issues? Time to consider your rollout plan? Time to keep on top of changes which are in use? etc...

Automated tests (including unit tests) are just one part of writing correct code. If you are asked, "How long is it going to take?" that implies finishing all aspects of coding required to get something correct into use. You prioritize that, not anyone else.

[zbentley]

I fully agree with all your points. My comment was based in my observations that, even given the truth of everything you said, "time to prepare automated tests" is usually one of the first things to shrink as unexpected events cause projects to slip on their timelines.

That's not a good thing, but it is a real thing: healthy organizations should respond by protecting that time, extending deadlines, and assessing what about their process and environment is causing planned timelines to not match reality ... but that doesn't always happen. When it doesn't happen, testing discipline can slip from (for example) "we need unit tests for complex logic modules, and integration tests for real networked service interactions, and at least 70% coverage" to "just get the happy path tested however you can so this feature makes it into the next release".

Given the reality that this will sometimes occur, engineers should remember to always prioritize the highest-value (that is, the maxima between time spent creating tests and defects that those tests can catch) testing work and methodologies. In good conditions, that will result in them writing the most important tests first and then writing any other tests they feel they need. But in bad conditions, this approach will still ensure that the most important automated verification is present.