Fix assert_eq!
test errors by editing the source code to match the test output.
Inspired by Mercurial's run-tests.py -i
.
cargo install cargo-fixeq
Write tests using assert_eq!
as usual. Put the code to evaluate on the left, leave a dummy value on the right:
fn f(n: usize) -> usize {
if n <= 2 { 1 } else { f(n - 1) + f(n - 2) }
}
#[test]
fn test_f() {
assert_eq!(f(10), 0);
assert_eq!(f(20), 0);
}
Run cargo fixeq
from the project root:
cargo fixeq
The dummy values are fixed automatically:
fn test_f() {
- assert_eq!(f(10), 0);
- assert_eq!(f(20), 0);
+ assert_eq!(f(10), 55);
+ assert_eq!(f(20), 6765);
}
In general, cargo-fixeq
can be helpful for writing initial tests and updating tests. See here for a more complicated real world example.
All parameters are passed to cargo test
. cargo-fixeq
does not define its own parameters.
cargo-fixeq 0.5
works for Rust >= 1.73, which changedassert_eq!
output format.cargo-fixeq 0.4
works for Rust < 1.73.
- expect-test: Lightweight snapshot testing.