Rust doc tests not running

Question

Hi I feel like I'm going crazy, but do I have wrong syntax here or something? My understanding was that docs are tested but I tried it and it doesn't get caught, I don't know what I'm doing wrong.

I'd expect the test to fail because both I haven't namespaced the method correctly and do the wrong calculation, but it appears to not be run?

cargo 1.44.1 (88ba85757 2020-06-11)

I was looking at the following: https://doc.rust-lang.org/book/ch14-02-publishing-to-crates-io.html

You can see in the output I'm just running cargo test

Answer 1

If you notice this message:

test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

No test is being run at all.

You'll have to move that code to a lib.rs file. Notice that in the documentation you linked also mentions the example file being Filename: src/lib.rs.

More generally, doctests don't work bin targets (where your main.rs is your entry point). There's a current open issue on the topic: https://github.com/rust-lang/rust/issues/50784