|
|
|
|
|
|
by sidlls
3327 days ago
|
|
|
And what about test coverage for the tests? You do realize that tests are also code, right? They have bugs, maintenance overhead, and all the other things code has. The worst code bases I've seen have more test code than code being tested. People try to write tests to cover every condition or input and in systems of even modest complexity that isn't possible, or at least not feasible in a finite time. |
|
|
Tests do have a maintenance cost, but it is much lower than the maintenance cost of code without tests. Without manual tests if there a bug it must be caught manually, this costs human time every time the tests are run. That also presumes the humans do the tests correctly, have a new team, QA person out sick, what is the cost now?
The cost of not having tests is bugs in production. If I write code and there a bug that impacts production many millions of dollars are on the line, and this is true for many developers. Write software for any airplane? Crashes can causes crashes so they are dangerous and expensive. How about something more common, Write software software for an online store? If the shopping cart drops 1 in 1000 items that is a huge amount of money, not just because of lost sales, but also angry customers. You will want to run the tests at least a few thousands times to catch that, a human won't do this, an automated unit test suite is shell script and VM away from doing that.
Automated tests don't make this impossible but it reduces the amount of bugs that can make it through. If a test costs 10 hours of developer time at $500/hour and stop one bug that would have alienated 1% of customers. Then there would only need to be 500,000 customers worth $1 each. Clearly these numbers have insanely inflated costs, yet they still make sense for many businesses. And this is only accounting for one bug. Finding that bug did not consume the test, it is still ready for more. A good test can many bugs and last many years.