Simple goldenfile testing in Rust.

Goldenfile tests generate one or more output files as they run. If any files differ from their checked-in "golden" version, the test fails. This ensures that behavioral changes are intentional, explicit, and version controlled.

You can use goldenfiles to test the output of a parser, the order of a graph traversal, the result of a simulation, or anything else that should only change with human review.

use goldenfile::Mint;
use std::io::Write;
let mut mint = Mint::new("tests/goldenfiles");
let mut file1 = mint.new_goldenfile("file1.txt").unwrap();
let mut file2 = mint.new_goldenfile("file2.txt").unwrap();
writeln!(file1, "Hello world!").unwrap();
writeln!(file2, "Foo bar!").unwrap();

When the Mint goes out of scope, it compares the contents of each file to its checked-in golden version and fails the test if they differ. To update the checked-in versions, run:

UPDATE_GOLDENFILES=1 cargo test

Pull requests are welcome! This project follows the Rust community's Code of Conduct.