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No, I literally mean that you can't prove correctness with tests, because you would need a lot of test cases to prove the simplest function.

For example: int addOne(int input) function would need test cases for every number in the int type, which would be 2,147,483,647 * 2 + 1 test case.

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The point of writing tests is to provide information, not prove correctness.

IE, a test is another way to explain what the developer of that test cared about, worried about, needed to verify of the code that is exercised.

Also, tests provide anothing built in consumer of the code, and all code with more consumers is better code, purely by surviving the stress.

It depends on the terms we set for our tests. Usually we infer things to be correct that are out of scope. For instance, my tests usually don't cover to test the runtime or hardware before executing tests. And what if laws of physics change? No seriously, I know what you mean. But I mean correctness in the bounds we set. Those bounds are different if you write software for aviation or biometric devices or an Instagram clone.

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