The question that matters is not whether automated tests improve code quality and productivity.
The question that needs to be answered is "if I took the time I previously spent on automated testing, and instead spent it on something else like code review or design review, would that result in greater code quality and productivity than automated testing did?"
And phrased that way, you see it's not a dichotomy. It depends on what you would spend the time on instead of automated testing. It depends on whether you already had peer review in your process. It depends on what sort of automated tests you spend time on. It's very hard to say something general without those details.
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Note that I'm not taking a stance against automated testing. I prefer working in a test-first style myself. I'm just saying it's not that simple.
The question that needs to be answered is "if I took the time I previously spent on automated testing, and instead spent it on something else like code review or design review, would that result in greater code quality and productivity than automated testing did?"
And phrased that way, you see it's not a dichotomy. It depends on what you would spend the time on instead of automated testing. It depends on whether you already had peer review in your process. It depends on what sort of automated tests you spend time on. It's very hard to say something general without those details.
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Note that I'm not taking a stance against automated testing. I prefer working in a test-first style myself. I'm just saying it's not that simple.