brix

Assertions for Emela's unit tests (spec 0040), distributed as a Pome (spec 0032).

Named after °Brix — the scale a grower uses to measure a fruit's sugar content: how you judge the quality of a Pome.

• Source path: github.com/emela-lang/brix
• Import root: brix (the source-path leaf; no [pome].module override)
• Requires: emela ≥ 0.6 (@test and emela test, specs 0039/0040)

Usage

Add brix as a development-time dependency (spec 0040 D1). It resolves for check / lint / LSP / test, and the compiler rejects any build artifact that would reach it (D4) — brix never becomes a runtime dependency of your Pome:

$ emela pome add --dev github:emela-lang/brix

Write tests next to the code they check (spec 0040 T7) — same file, so private functions are testable by bare name — and run them:

module rle

import brix.assert

fn run_length(s: String) -> Int uses {} {
    ...
}

@test
fn empty_input_has_zero_runs() -> Unit uses {} {
    assert.eq(run_length(""), 0)
}

$ emela test
running 1 test
test rle.empty_input_has_zero_runs ... ok

test result: ok. 1 passed; 0 failed

A @test body is an implicit-try scope (spec 0040 T3): a failed assertion throws, the throw propagates as the test's failure at that point, and no ? is needed. The runner knows nothing about this library beyond "an uncaught throw fails the test" (B1/C4); the Show impl on AssertError is what renders the failure detail (C7):

---- rle.empty_input_has_zero_runs ----
threw AssertError: assertion failed: expected `0`, got `1`

API (module brix.assert)

Function	Fails when
eq<T: Eq + Show>(actual, expected)	the values differ
ne<T: Eq + Show>(actual, unexpected)	the values are equal
ok(condition)	the condition is false
fail(message)	always

Every assertion returns Unit and throws AssertError; brix is pure Emela with no compiler privileges, so alternative assertion libraries compose the same way.

Testing

brix tests itself with its own assertions — the @test functions live beside the API in src/assert.emel:

$ emela test