test
test "name" { … }
A test "name" { … } block declares a named test. Every test in a file is discovered automatically and run by a generated entry point — there is no entry to write and nothing to register. The runner prints ok - name for a test whose assertions all held and FAIL - name for one that had a failure, then a == N passed, M failed == summary, and the program exits non-zero if any test failed. Writing a test should feel like writing a function: put a few assertions in a block and run it.
Assertions (each records a failure and prints file:line: … failed but keeps going, so one run reports every failure):
- expect(cond) — the boolean cond must be true.
- expect_eq(a, b) — a must equal b; on failure prints (got a, want b).
- expect_near(a, b, tol) — a must be within tol of b (absolute). Use it for fixed-point results and accumulated integer math, where an exact match is too brittle.
Run a spec file directly with the compiler-runner — ludic mymath_test.ludic compiles it to a native binary, runs it, and forwards the pass/fail exit code — so it drops straight into bin/ludic and CI.
Line coverage. Compile with the --coverage flag and the compiler instruments every statement with a per-source-line hit counter; at exit the counts are written to the file named by $LUDIC_COVERAGE (default ludic.cov) as a FILE <name> header followed by one <line> <hits> row per instrumented line. The instrumentation is flag-gated and additive, so an ordinary build — and the compiler's own self-compile — stays byte-identical. bin/ludic-dev test --coverage compiles the test specs this way, runs them, and aggregates the dumps into a per-file report that names the lines your tests never reached:
``
== line coverage (bin/ludic-dev test --coverage) ==
examples/library/coverage.ludic 16/17 lines 94% uncovered: 33
examples/library/testing.ludic 17/17 lines 100%
----
total: 33/34 lines 97%
``
Example
program MathSpec {
function add(a: int, b: int) -> int { return a + b }
test "addition adds" {
expect_eq(add(2, 3), 5)
expect(add(1, 1) == 2)
}
test "fixed math is close enough" {
let half = fixed(1) / 2 # 0.5 in Q16.16
expect_near(half, 32768, 2) # within 2 raw units of 0.5
}
}