Testing and Assertion

Assert Statement

assert takes a bool value. If false, immediately exit script with non-zero code.

assert(1 == 1)
assert(1 == 2) // assertion failed

println('unreachable')

assert takes a message as second argument desplayed when the assertion fails.

fn div(a: int, b: int): int {
  assert(b == 0, 'divide by zero')
  return a / b
}

A function have #[test] attribute is a testing function. Testing functions are compiled only in test-mode and skipped for normal compilation.

If an assertion fails within a test function, only that test will be terminated and other tests will run.

// test.li
namespace tests {
  #[test]
  fn test_fail() {
    assert(false)
  }

  #[test]
  fn test_ok() {
    assert(true)
  }
}

Use the lic test command to run tests.

lic test test.li

You run the above command, then you take the following results.

testing tests::test_fail ... FAILED
testing tests::test_ok ... OK

Output:
LINE 9: Assertion Failed

test result: FAILED
2 total; 1 passed; 1 failed;