Test Organization

The Mana community thinks about tests in two categories: unit tests and integration tests.

Unit Tests

Unit tests are small, focused, and test one module in isolation. Place them in the same file as the code they test:

fn add_two(a: int) -> int {
    return internal_adder(a, 2)
}
 
fn internal_adder(a: int, b: int) -> int {
    return a + b
}
 
#[cfg(test)]
module tests {
    use super::*
 
    #[test]
    fn internal() {
        assert_eq(4, internal_adder(2, 2))
    }
}

The #[cfg(test)] annotation tells Mana to compile and run the test code only with mana test.

Testing Private Functions

Mana allows testing private functions:

fn internal_adder(a: int, b: int) -> int {
    return a + b
}
 
#[cfg(test)]
module tests {
    use super::*
 
    #[test]
    fn test_internal() {
        assert_eq(internal_adder(2, 2), 4)
    }
}

Integration Tests

Integration tests are external to your library. Create a tests directory:

my_project/
├── project.mana
├── src/
│   └── lib.mana
└── tests/
    └── integration_test.mana

tests/integration_test.mana:

use my_project
 
#[test]
fn it_adds_two() {
    assert_eq(4, my_project::add_two(2))
}

Each file in tests/ is a separate crate. Run a specific integration test file:

mana test --test integration_test

Submodules in Integration Tests

Create shared helper code in tests/common/mod.mana:

tests/
├── common/
│   └── mod.mana
└── integration_test.mana

tests/common/mod.mana:

pub fn setup() {
    // Setup code
}

tests/integration_test.mana:

use my_project
module common
 
#[test]
fn it_adds_two() {
    common::setup()
    assert_eq(4, my_project::add_two(2))
}

Summary

Mana's testing features help you specify how code should behave. Unit tests exercise different parts of a library separately and can test private implementation details. Integration tests check that parts of the library work together correctly.

Explore the Appendix for reference material.