`std.test`¶

Mighty-native test runner. Distinct from cargo test (which tests the compiler); this runs .sd test files inside a Mighty package.

Quick start¶

Put test files under tests/ in your package:

my-package/
├── mighty.toml
├── src/
│   └── main.sd
└── tests/
    └── basic_test.sd

tests/basic_test.sd:

fn test_addition_works() {
  let x = 1 + 2
  // a non-trapping body counts as a passing test.
}

fn test_panics_fails() {
  panic("intentional")
}

Run with:

mty-test
# tests/basic_test.sd ... ok
# tests/basic_test.sd ... FAILED
#   reason: trap MT0901: intentional
# test result: 1 passed; 1 failed; 2 total

Exit code: 0 on all-pass, 1 on any failure.

Discovery¶

Walks tests/ (or --dir <path>) recursively.
Every .sd file is considered.
Every top-level fn whose name begins with test_ is a test.
Files are visited in lexicographic order; tests within a file run in declaration order.

Execution¶

Each test file is parsed → HIR-lowered → type-+borrow-checked → MtyIR-lowered → invoked through the MtyIR interpreter (run_fn_with_budget) with a 5,000,000-step budget per test.

A test passes if its body returns normally. A test fails if it traps (via panic or any other trap), exhausts the step budget, or returns a non-zero exit.

Reporter¶

cargo test-shaped:

test basic_test::test_addition_works ... ok
test basic_test::test_panics_fails ... FAILED
  reason: trap MT0901: intentional

test result: 1 passed; 1 failed; 2 total

Determinism¶

The runner uses the slice-6 MtyIR interpreter, which is fully deterministic given the same input. v0.3 will add a --seed <N> flag (spec §A39) for tests that exercise the deterministic-runtime seed surface.

CLI surface¶

mty-test [--dir <path>]

--dir <path> overrides the default tests/.
--help prints usage.

In v0.3 this merges into the main mty CLI as mty test.

Known limits (v0.2)¶

The test_ name prefix is the only discovery rule. A proper test fn name() { ... } syntax + #[test] attribute is planned for v0.3 (requires a parser change that lives outside this slice's work area).
No per-test deterministic-seed plumbing yet (A39).
No parallel test execution (interpreter is single-threaded).

std.test¶