I just do copy the first unit test sample into a file named t.rs, then run 'cargo test', it report error.
After read the book, I change the process to
cargo new --lib add
cd add
vim src/lib.rs ## copy & paste the example code here
cargo test # it works now.
My suggestion is do a brief description about how to play the 'unittest' code, to let those readers who still not read the book can also complete the examples.
the first example 'cargo test' can not work #1665
https://doc.rust-lang.org/stable/rust-by-example/testing/unit_testing.html
I just do copy the first unit test sample into a file named t.rs, then run 'cargo test', it report error.
After read the book, I change the process to
My suggestion is do a brief description about how to play the 'unittest' code, to let those readers who still not read the book can also complete the examples.