feat(client): Add support for tags

README.md

@@ -155,6 +155,7 @@ This module exports:
     -   `udpDnsCacheTTL`: Optional. Default `120`. Dns cache Time to live in seconds.
     -   `onError`: Optional. Default `(err) => void`. Called when there is an error. Allows you to check also send errors.
     -   `customSocket`: Optional. Default `null`. Custom socket used by the client, this is a feature for mocking we do not recommend using it in production.
+    -   `tags`: Optional Default `null`. If provided, metrics will include tags in the form `#key1:value1,key2:value2`.
 
 #### `Client.close([cb])`
 
@@ -328,5 +329,5 @@ If you have any questions on how to use dats, bugs and enhancement please feel f
 
 ## License
 
-dats is licensed under the MIT license.  
+dats is licensed under the MIT license.
 See the [LICENSE](./LICENSE) file for more information.

src/index.ts

@@ -20,6 +20,8 @@ export enum Types {
 
 Object.freeze(Types);
 
+export type Tags = { [key: string]: string | null } | string[];
+
 export interface Options {
     host?: string | URL;
     namespace?: string;
@@ -30,6 +32,7 @@ export interface Options {
     udpDnsCache?: boolean;
     udpDnsCacheTTL?: number;
     customSocket?: Socket;
+    tags?: Tags;
 }
 
 /**
@@ -49,6 +52,7 @@ class Client {
     protected namespace: string;
     protected debug: DebugLogger;
     protected isDebug: boolean;
+    protected tags: string;
 
     constructor({
         host,
@@ -60,6 +64,7 @@ class Client {
         debug = null,
         onError = () => undefined,
         customSocket = null,
+        tags = null,
     }: Options = {}) {
         if (typeof namespace !== 'string') {
             throw new Error('A namespace string is required');
@@ -122,6 +127,15 @@ class Client {
         this.bufferFlushTimeout = bufferFlushTimeout;
         this.timeout = null;
         this.timeoutActive = false;
+        if (tags) {
+            if (Array.isArray(tags)) {
+                this.tags = tags.join(',');
+            } else {
+                this.tags = Object.keys(tags)
+                    .map((tag) => (tags[tag] ? `${tag}:${tags[tag]}` : tag))
+                    .join(',');
+            }
+        }
     }
 
     connect(): Promise<boolean> {
@@ -144,6 +158,10 @@ class Client {
             metric += '|@' + sampling;
         }
 
+        if (this.tags) {
+            metric += `|#${this.tags}`;
+        }
+
         return metric;
     }
     /**

test/index.spec.ts

@@ -111,6 +111,23 @@ test('counter with sampling', (t) => {
     });
 });
 
+test('counter with tags', (t) => {
+    const host = new URL(`udp://127.0.0.1:${t.context.address.port}`);
+    const namespace = 'ns1';
+    const tags = { tag1: 'value1', tag2: null, tag3: 'value3' };
+    const client = new Client({ host, namespace, tags });
+    return new Promise<number>((resolve) => {
+        t.context.server.on('metric', (metric) => {
+            t.is(
+                `${namespace}.some.metric:1|c|@10|#tag1:value1,tag2,tag3:value3`,
+                metric.toString()
+            );
+            return resolve(0);
+        });
+        client.counter('some.metric', 1, 10);
+    });
+});
+
 test('timing', (t) => {
     const host = new URL(`udp://127.0.0.1:${t.context.address.port}`);
     const namespace = 'ns1';
@@ -137,6 +154,23 @@ test('timing with sampling', (t) => {
     });
 });
 
+test('timing with tags', (t) => {
+    const host = new URL(`udp://127.0.0.1:${t.context.address.port}`);
+    const namespace = 'ns1';
+    const tags = { tag1: 'value1', tag2: null, tag3: 'value3' };
+    const client = new Client({ host, namespace, tags });
+    return new Promise<number>((resolve) => {
+        t.context.server.on('metric', (metric) => {
+            t.is(
+                `${namespace}.some.metric:1|ms|@10|#tag1:value1,tag2,tag3:value3`,
+                metric.toString()
+            );
+            return resolve(0);
+        });
+        client.timing('some.metric', 1, 10);
+    });
+});
+
 test('gauge', (t) => {
     const host = new URL(`udp://127.0.0.1:${t.context.address.port}`);
     const namespace = 'ns1';
@@ -163,6 +197,23 @@ test('gauge should ignore sampling', (t) => {
     });
 });
 
+test('gauge with tags', (t) => {
+    const host = new URL(`udp://127.0.0.1:${t.context.address.port}`);
+    const namespace = 'ns1';
+    const tags = { tag1: 'value1', tag2: null, tag3: 'value3' };
+    const client = new Client({ host, namespace, tags });
+    return new Promise<number>((resolve) => {
+        t.context.server.on('metric', (metric) => {
+            t.is(
+                `${namespace}.some.metric:1|g|#tag1:value1,tag2,tag3:value3`,
+                metric.toString()
+            );
+            return resolve(0);
+        });
+        client.gauge('some.metric', 1);
+    });
+});
+
 test('set', (t) => {
     const host = new URL(`udp://127.0.0.1:${t.context.address.port}`);
     const namespace = 'ns1';
@@ -189,6 +240,23 @@ test('set should ignore sampling', (t) => {
     });
 });
 
+test('set with tags', (t) => {
+    const host = new URL(`udp://127.0.0.1:${t.context.address.port}`);
+    const namespace = 'ns1';
+    const tags = { tag1: 'value1', tag2: null, tag3: 'value3' };
+    const client = new Client({ host, namespace, tags });
+    return new Promise<number>((resolve) => {
+        t.context.server.on('metric', (metric) => {
+            t.is(
+                `${namespace}.some.metric:1|s|#tag1:value1,tag2,tag3:value3`,
+                metric.toString()
+            );
+            return resolve(0);
+        });
+        client.set('some.metric', 1);
+    });
+});
+
 test.serial('hostname substitution', (t) => {
     const host = new URL(`udp://127.0.0.1:${t.context.address.port}`);
     const namespace = 'ns1.${hostname}';