Notes

my notes as I go through this book

cargo test ->run unit tests
cargo fmt --all -- --check -> looks for unformatted code
cargo clippy -- -D warnings -> runs lint and fails on warning
cargo tarpaulin --ignore-tests -> runs code coverage - tests
start db docker first time: ./scripts/db_init
start it again when already running: SKIP_DOCKER=true ./scripts/init_db.sh
cargo *nughtly udeps - looks for dependencies not being used
TEST_LOG=true cargo test | bunyan - run tests with logging
cargo sqlx prepare -- --lib -> perform sqlx functions to mock offline to sqlx-data.json

serde slower due to the fact that it is generic over the underlying data formats? No, thanks to a process called monomorphization. Every time a generic function is called with a concrete set of types, the Rust compiler will create 22You can look at serde_json’s serialize_seq implementation for confirmation: here. There is an optimisation for empty sequences (you immediately output []), but that is pretty much what is happening. 46 a copy of the function body replacing the generic type parameters with the concrete types. This allows the compiler to optimize each instance of the function body with respect to the concrete types involved: the result is no different from what we would have achieved writing down separate functions for each type, without using generics or traits. In other words, we do not pay any runtime costs for using generics23.
seems gross to have db connection checked in but the env file is only for tests, not for after compiling like the yaml