Add type definition

metric.d.ts

@@ -0,0 +1,80 @@
+/**
+ * A hint of what type of metric this is. Each numeric value represents a different type of metric:
+ *
+ *  - `0`: `unknown`
+ *  - `1`: `gauge`
+ *  - `2`: `counter`
+ *  - `3`: `state_set`
+ *  - `4`: `info`
+ *  - `5`: `cumulative histogram`
+ *  - `6`: `gauge histogram`
+ *  - `7`: `summary`
+ */
+export type MetricType = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7;
+
+export type MetricLabel = {
+  /**
+   * The name must match the regular expression `[a-zA-Z0-9_]`.
+   */
+  name: string;
+  value: string | number | boolean | null;
+}
+
+export type MetricOptions = {
+  /**
+   * The name must match the regular expression `[a-zA-Z_:][a-zA-Z0-9_:]*`.
+   *
+   * By convention, colons are reserved for monitoring system use, and names
+   * beginning with underscores are reserved for monitoring-system internal use.
+   */
+  name: string;
+  description: string;
+  /**
+   * @default Date.now() / 1000
+   */
+  timestamp?: number | null;
+  /**
+   * @deprecated Use `timestamp` instead.
+   */
+  time?: number | null;
+  source?: string | null;
+  labels?: Array<MetricLabel>;
+  value?: number | null;
+  /**
+   * @default 0 (`unknown`)
+   */
+  type?: MetricType;
+  /**
+   * Arbitrary metadata to attach to this metric. This field is not validated.
+   * @default {}
+   */
+  meta?: unknown;
+}
+
+export default class Metric {
+    constructor(args: MetricOptions);
+
+    name: Readonly<string>;
+    description: Readonly<string>;
+    value: Readonly<number | null>;
+    type: Readonly<MetricType>;
+    source: string | null;
+    timestamp: Readonly<number | null>;
+    /**
+     * @deprecated Use `timestamp` instead.
+     */
+    time: Readonly<number | null>;
+    labels: Readonly<Array<MetricLabel>>;
+    meta: Readonly<unknown>;
+
+    toJSON(): {
+      name: string;
+      description: string;
+      timestamp: number | null;
+      type: MetricType;
+      value: number | null;
+      labels: Array<MetricLabel>;
+      time: number | null;
+      meta: unknown;
+    };
+}

package.json

@@ -1,10 +1,12 @@
 {
   "name": "@metrics/metric",
-  "version": "2.3.1",
+  "version": "2.3.2",
   "description": "The metric class definition which metric objects in the @metrics library is instansiated from",
   "main": "lib/metric.js",
+  "types": "metric.d.ts",
   "files": [
-    "lib"
+    "lib",
+    "metric.d.ts"
   ],
   "scripts": {
     "bench": "node benchmark/benchmark.js",