1 files changed, 37 insertions, 0 deletions
diff --git a/tst/trace_util.test.ts b/tst/trace_util.test.ts
new file mode 100644
index 0000000..d36226d
--- /dev/null
+++ b/tst/trace_util.test.ts
@@ -0,0 +1,37 @@
+import { Either, Metric, TraceUtil } from '../lib/index';
+import { CollectingTrace, TestTraceable } from './test_utils';
+
+describe('trace/util (TraceUtil)', () => {
+    test('withFunctionTrace adds fn scope', () => {
+        const trace = new CollectingTrace<any>();
+        const t = TestTraceable.of(1, trace);
+
+        const out = t.flatMap(TraceUtil.withFunctionTrace(function hello() {}));
+        out.trace.trace('x');
+
+        const flattened = trace.events.flatMap((e) => e);
+        expect(flattened.some((x) => x === 'fn.hello')).toBe(true);
+    });
+
+    test('traceResultingEither emits metric success/failure', () => {
+        const metric = Metric.fromName('Job').asResult();
+        const trace = new CollectingTrace<any>();
+
+        const ok = TestTraceable.of(Either.right<Error, string>('ok'), trace).map(
+            TraceUtil.traceResultingEither(metric),
+        );
+        ok.get();
+
+        const flattened = trace.events.flatMap((e) => e);
+        expect(flattened.some((x: any) => typeof x === 'object' && x?.name === 'Job.success')).toBe(true);
+
+        const trace2 = new CollectingTrace<any>();
+        const bad = TestTraceable.of(Either.left<Error, string>(new Error('nope')), trace2).map(
+            TraceUtil.traceResultingEither(metric),
+        );
+        bad.get();
+
+        const flattened2 = trace2.events.flatMap((e) => e);
+        expect(flattened2.some((x: any) => typeof x === 'object' && x?.name === 'Job.failure')).toBe(true);
+    });
+});