/** The smallest test harness that gives a useful failure message. */

let failures = 0;
let checks = 0;

export function ok(cond, msg) {
  checks++;
  if (!cond) {
    failures++;
    console.error('  FAIL  ' + msg);
  }
}

export function near(actual, expected, tol, msg) {
  ok(Math.abs(actual - expected) <= tol, `${msg} (got ${actual}, want ${expected} ±${tol})`);
}

export function section(name) {
  console.log('· ' + name);
}

export function done(name) {
  if (failures) {
    console.error(`\n${name}: ${failures} of ${checks} checks failed`);
    process.exit(1);
  }
  console.log(`${name}: ${checks} checks passed`);
}