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Comment by dmurray | Hacker News Reader

Go doesn't have assertions. Of course it is not hard to mimic them, but it's an intentional choice to increase the friction of doing that and make it feel unidiomatic.

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I should not have used the word "assertion". I meant it in the more general way of "code that checks some property", not a literal "assert" feature as built in to the language.

I was just pointing out that this bug basically requires an explicit test checking for exactly the bug. Fuzzing would not have found the check for you.

Does Go really aim to discourage the programmer from adding runtime checks? What's the reasoning there?

An assertion, I think, would crash the program. In that sense implementing them is simple - just panic when the condition is violated. Go prefers plain checks that return errors, though. Panics should be used for truly unexpected conditions, such as a nil pointer. Invalid input, as in this case, would be better served as an error.

> Panics should be used for truly unexpected conditions, such as a nil pointer.

Exceptional cases, if you will.

I find it funny when people say Go doesn't have exceptions when Go is the only mainstream language that advocates for and prefers the use of exceptions.

To encourage "proper error handling and reporting" according to the FAQ.

https://golang.org/doc/faq#assertions

Yes, Go really does discourage assertions.

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