Initial commit

test/harness.mjs

@@ -0,0 +1,28 @@
+/** 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`);
+}