1 files changed, 41 insertions, 0 deletions
diff --git a/u/trace/metric/index.ts b/u/trace/metric/index.ts
new file mode 100644
index 0000000..72c37d2
--- /dev/null
+++ b/u/trace/metric/index.ts
@@ -0,0 +1,41 @@
+import { isTagged, Tagged, type Mapper } from '@emprespresso/pengueno';
+
+export enum Unit {
+    COUNT = 'COUNT',
+    MILLISECONDS = 'MILLISECONDS',
+}
+
+export const MetricValueTag = 'MetricValue' as const;
+export type MetricValueTag = typeof MetricValueTag;
+export const isMetricValue = (t: unknown): t is MetricValue => isTagged(t, MetricValueTag);
+export interface MetricValue extends Tagged<MetricValueTag> {
+    readonly name: string;
+    readonly unit: Unit;
+    readonly value: number;
+    readonly emissionTimestamp: number;
+}
+
+export interface IEmittableMetric {
+    readonly name: string;
+    readonly unit: Unit;
+    readonly withValue: Mapper<number, MetricValue>;
+}
+
+export const IMetricTag = 'IMetric' as const;
+export type IMetricTag = typeof IMetricTag;
+export const isIMetric = (t: unknown): t is IMetric => isTagged(t, IMetricTag);
+export interface IMetric extends Tagged<IMetricTag> {
+    readonly count: IEmittableMetric;
+    readonly time: IEmittableMetric;
+    readonly parent: undefined | IMetric;
+}
+
+export interface IResultMetric extends IMetric {
+    readonly failure: IMetric;
+    readonly success: IMetric;
+    readonly warn: IMetric;
+}
+
+export * from './emittable.js';
+export * from './metric.js';
+export * from './trace.js';