regression-test

This crate provides you with the tools to write regression tests for your Rust code. It can either be used directly as a library or through the regression-test-macros crate, which provides convenient macros for writing tests.

Under the hood, it uses serde for serialization and deserialization of test data. When first run, it will create a JSON file containing the expected output of the test. On subsequent runs, it will compare the actual output of the test with the expected output in the JSON file.

To regenerate the expected output, simply delete the JSON file and run the test again.

If you are using the regression-test-macros crate, you can use the #[regtest] attribute macro to mark your test functions. This macro will automatically handle the initialization of the RegTest struct and will place the generated data in an appropriate place.

Usage

use regression_test::RegTest;

#[test]
fn my_test() {
    let mut rt = RegTest::new("./my_test.json");

    let result = 2 + 2; // complex calculation

    // For structures that implement `Display`:
    rt.regtest(result);

    // For structures that implement `Debug`:
    rt.regtest_dbg(result);
}

You can also use the regression-test-macros crate to simplify your tests:

use regression_test_macros::regtest;
use regression_test::RegTest;

// Note: you must have the first argument of the function be a `RegTest` instance
#[regtest]
fn my_test(mut rt: RegTest) {
    let result = 2 + 2; // complex calculation

    // For structures that implement `Display`:
    rt.regtest(result);

    // For structures that implement `Debug`:
    rt.regtest_dbg(result);
}