feat: make inital metrics interval configurable.

README.md

@@ -123,6 +123,7 @@ The Unleash SDK takes the following options:
 | refreshInterval   | no | `30` | How often, in seconds, the SDK should check for updated toggle configuration. If set to 0 will disable checking for updates                 |
 | disableRefresh    | no | `false` | If set to true, the client will not check for updated toggle configuration                                                                |
 | metricsInterval   | no | `60` | How often, in seconds, the SDK should send usage metrics back to Unleash Proxy                                                              | 
+| metricsIntervalInitial | no | `2` | How long the SDK should wait for the first metrics report back to the Unleash API. It cannot be longer than the `metricsInterval`. If you want to disable the initial metrics call you can set it to 0. | 
 | disableMetrics    | no | `false` | Set this option to `true` if you want to disable usage metrics                                                                           |
 | storageProvider   | no | `LocalStorageProvider` in browser, `InMemoryStorageProvider` otherwise | Allows you to inject a custom storeProvider                                                                              |
 | fetch             | no | `window.fetch` or global `fetch` | Allows you to override the fetch implementation to use. Useful in Node.js environments where you can inject `node-fetch`                    | 

src/index.ts

@@ -41,6 +41,7 @@ interface IConfig extends IStaticContext {
     disableRefresh?: boolean;
     refreshInterval?: number;
     metricsInterval?: number;
+    metricsIntervalInitial?: number;
     disableMetrics?: boolean;
     storageProvider?: IStorageProvider;
     context?: IMutableContext;
@@ -153,6 +154,7 @@ export class UnleashClient extends TinyEmitter {
         disableRefresh = false,
         refreshInterval = 30,
         metricsInterval = 30,
+        metricsIntervalInitial = 2,
         disableMetrics = false,
         appName,
         environment = 'default',
@@ -232,6 +234,7 @@ export class UnleashClient extends TinyEmitter {
             fetch,
             headerName,
             customHeaders,
+            metricsIntervalInitial,
         });
     }
 

src/metrics.test.ts

@@ -21,6 +21,7 @@ test('should be disabled by flag disableMetrics', async () => {
         clientKey: '123',
         fetch: fetchMock,
         headerName: 'Authorization',
+        metricsIntervalInitial: 0,
     });
 
     metrics.count('foo', true);
@@ -40,6 +41,7 @@ test('should send metrics', async () => {
         clientKey: '123',
         fetch: fetchMock,
         headerName: 'Authorization',
+        metricsIntervalInitial: 0,
     });
 
     metrics.count('foo', true);
@@ -76,6 +78,7 @@ test('should send metrics with custom auth header', async () => {
         clientKey: '123',
         fetch: fetchMock,
         headerName: 'NotAuthorization',
+        metricsIntervalInitial: 0,
     });
 
     metrics.count('foo', true);
@@ -99,6 +102,7 @@ test('Should send initial metrics after 2 seconds', () => {
         clientKey: '123',
         fetch: fetchMock,
         headerName: 'Authorization',
+        metricsIntervalInitial: 2,
     });
 
     metrics.start();
@@ -112,6 +116,54 @@ test('Should send initial metrics after 2 seconds', () => {
     expect(fetchMock.mock.calls.length).toEqual(1);
 });
 
+test('Should send initial metrics after 5 seconds, when metricsIntervalInitial is higher than metricsInterval', () => {
+    const metrics = new Metrics({
+        onError: console.error,
+        appName: 'test',
+        metricsInterval: 5,
+        disableMetrics: false,
+        url: 'http://localhost:3000',
+        clientKey: '123',
+        fetch: fetchMock,
+        headerName: 'Authorization',
+        metricsIntervalInitial: 20,
+    });
+
+    metrics.start();
+
+    metrics.count('foo', true);
+    metrics.count('foo', true);
+    metrics.count('foo', false);
+    metrics.count('bar', false);
+    // Account for 2 second timeout before the set interval starts
+    jest.advanceTimersByTime(5000);
+    expect(fetchMock.mock.calls.length).toEqual(1);
+});
+
+test('Should not send initial metrics if disabled', () => {
+    const metrics = new Metrics({
+        onError: console.error,
+        appName: 'test',
+        metricsInterval: 5,
+        disableMetrics: false,
+        url: 'http://localhost:3000',
+        clientKey: '123',
+        fetch: fetchMock,
+        headerName: 'Authorization',
+        metricsIntervalInitial: 0,
+    });
+
+    metrics.start();
+
+    metrics.count('foo', true);
+    metrics.count('foo', true);
+    metrics.count('foo', false);
+    metrics.count('bar', false);
+    // Account for 2 second timeout before the set interval starts
+    jest.advanceTimersByTime(2000);
+    expect(fetchMock.mock.calls.length).toEqual(0);
+});
+
 test('should send metrics based on timer interval', async () => {
     const metrics = new Metrics({
         onError: console.error,
@@ -122,6 +174,7 @@ test('should send metrics based on timer interval', async () => {
         clientKey: '123',
         fetch: fetchMock,
         headerName: 'Authorization',
+        metricsIntervalInitial: 2,
     });
 
     metrics.start();
@@ -162,6 +215,7 @@ describe('Custom headers for metrics', () => {
             fetch: fetchMock,
             headerName: 'Authorization',
             customHeaders,
+            metricsIntervalInitial: 2,
         });
 
         metrics.count('foo', true);

src/metrics.ts

@@ -13,6 +13,7 @@ export interface MetricsOptions {
     fetch: any;
     headerName: string;
     customHeaders?: Record<string, string>;
+    metricsIntervalInitial: number;
 }
 
 interface VariantBucket {
@@ -51,6 +52,7 @@ export default class Metrics {
     private fetch: any;
     private headerName: string;
     private customHeaders: Record<string, string>;
+    private metricsIntervalInitial: number;
 
     constructor({
         onError,
@@ -63,18 +65,21 @@ export default class Metrics {
         fetch,
         headerName,
         customHeaders = {},
+        metricsIntervalInitial,
     }: MetricsOptions) {
         this.onError = onError;
         this.onSent = onSent || doNothing;
         this.disabled = disableMetrics;
         this.metricsInterval = metricsInterval * 1000;
+        this.metricsIntervalInitial = Math.min(metricsInterval, metricsIntervalInitial) * 1000;
         this.appName = appName;
         this.url = url instanceof URL ? url : new URL(url);
         this.clientKey = clientKey;
         this.bucket = this.createEmptyBucket();
         this.fetch = fetch;
         this.headerName = headerName;
         this.customHeaders = customHeaders;
+
     }
 
     public start() {
@@ -87,10 +92,15 @@ export default class Metrics {
             this.metricsInterval > 0
         ) {
             // send first metrics after two seconds.
-            setTimeout(() => {
+            if(this.metricsIntervalInitial > 0) {
+                setTimeout(() => {
+                    this.startTimer();
+                    this.sendMetrics();
+                }, this.metricsIntervalInitial);
+            } else {
                 this.startTimer();
-                this.sendMetrics();
-            }, 2000);
+            }
+
         }
     }