[9rx]

> stuck relying on a linter to catch you

Isn't that what your tests are for? Linters aren't normally intended to stop you from creating undefined behaviour.

It is not like Rust negates the need for those tests. Remembering to handle an error is not sufficient. You also need to ensure that you handle it correctly and define a contract to ensure that the intent is documented for human consumption and remains handled correctly as changes are made. Rust is very much a language designed around testing like every other popular language.

[Dylan16807]

Relying on (someone making) a test to ensure you use a variable is even worse than relying on a linter.

[9rx]

You are absolutely right. But why would anyone do that? That doesn't make sense and it is bizarre that you would even put in the time to post this.

What you do need to do is document how the function is intended to behave. If, for example, your function opens a file, you need to describe to other developers what is expected to happen when the file cannot be open.

"The compiler won't let me forget to handle the error" is not sufficient to answer that. That you need to handle the error is a reasonable assumption, but upon error... Should it return a subsequent error? Should it try to open a file on another device? Should it fall back to using a network resource? That is what you need to answer.

And tests are the way to answer it. It is quite straightforward to do so: You write a test that sees the file open failure occur and check that the expected result happened (it returned the right error, it returned the right result from the network resource, etc.). Other programmers can then read your example to understand what is expected of the function. This is as necessary in Rust as it is in Go as it is in any other language you are conceivably going to be using. Otherwise, once you are gone, how will anyone ever know what it is supposed to do? As changes occur through the ongoing development cycle, how will they ever ensure that they haven't broken away from your original intent?

So, once you've written the necessary tests – those that are equally necessary in Rust as in any other language – how, exactly, are you going to forget to handle the error? You can't! It's impossible.

I don't know why this silly thought persists. It is so painfully contrived. If one is a complete dummy who doesn't understand the software development process perhaps they can go out of their way to make it a problem, but if one is that much of dummy they won't be able to grasp the complexities of Rust anyway, so...