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>The kinds of bugs that get caught by a static type system are also caught by a good suite of automated tests, where every test is written before the production code that makes it pass.

That's not a small thing though. It's one extra thing that you just have with static typing. Not that you don't need tests but at least you will have already some bases covered.

For me a big reason of why I like static types it's the ease of reading even if a developer was sloppy. I have read dynamically typed code where the same parameter can be a string or an array or an object depending on what's the weather like outside when a dev needs to call a function. This sort of confusion makes it exponentially harder to read and understand code IMHO.

> The kinds of bugs that get caught by a static type system are also caught by a good suite of automated

This is correct in theory, but to get the same benefit you'll need to write all the tests that the static language would guarantee. That's both relying on the programmer being always correct and that they think the time writing those tests is worth it.

Stating typing you have to explicitly opt out of, and automated tests you have to go to quite some effort to explicitly opt into, and most teams I've been on have been quite poor at this opting in.

Code is worked out until it has few enough bugs for the customer to accept it. A program bug count is a function of how it will be used, and how sloppy the developers (or their company) thinks they can get away with, it's almost no sensitive to how easy or hard it is to find and correct the bugs.

That said, Java's type system sucks, you can not extrapolate its problems into a general concept.

> The kinds of bugs that get caught by a static type system are also caught by a good suite of automated tests, where every test is written before the production code that makes it pass.

To make matters worse, one would also have to write tests that cover every possible path through the function to ensure none of them change a value into a shape the rest of the code doesn't expected. This gets very tedious if it has to be done for every function.

> The kinds of bugs that get caught by a static type system are also caught by a good suite of automated tests, where every test is written before the production code that makes it pass.

Mostly, but it depends how you're using the type system. I have a talk (slides at https://dlthomas.github.io/using-c-types-talk/slides/slides....) that ends with enlisting the C type system to statically catch a "you called this from the wrong thread" error - with no run-time overhead.

> Programs written in dynamically typed languages don’t have far higher defect rates than programs written in languages like C++ and Java.

They have done a study which found that strong/static type checks can reduce your number of bugs by 15%

https://blog.acolyer.org/2017/09/19/to-type-or-not-to-type-q...

I would consider that to be quite significant