filter

packages/sources/datalayer/src/__tests__/index.test.ts

@@ -1,7 +1,7 @@
 /* eslint-disable prefer-rest-params */
 import type { DataLayer } from '../types';
 import { sourceDataLayer } from '..';
-import { isArray } from '@elbwalker/utils';
+import { isArray, isObject } from '@elbwalker/utils';
 
 describe('source dataLayer', () => {
   const elb = jest.fn(); //.mockImplementation(console.log);
@@ -62,6 +62,27 @@ describe('source dataLayer', () => {
     });
   });
 
+  test('filter', () => {
+    const mockFn = jest.fn();
+    sourceDataLayer({
+      elb,
+      filter: (event) => {
+        mockFn(event);
+        return isObject(event) && event.event !== 'foo';
+      },
+    });
+
+    let event = { event: 'foo' };
+    dataLayer.push(event);
+    expect(elb).toHaveBeenCalledTimes(0);
+    expect(mockFn).toHaveBeenCalledWith(event);
+
+    event = { event: 'bar' };
+    dataLayer.push(event);
+    expect(elb).toHaveBeenCalledTimes(1);
+    expect(mockFn).toHaveBeenCalledWith(event);
+  });
+
   test('prefix', () => {
     sourceDataLayer({ elb, prefix: 'foo' });
     dataLayer.push({ event: 'bar baz' });

packages/sources/datalayer/src/push.ts

@@ -38,6 +38,9 @@ export function push(config: Config, ...args: unknown[]) {
 
       config.processing = true;
       entries.forEach((obj) => {
+        // Filter out unwanted events
+        if (config.filter && !config.filter(obj)) return;
+
         // Map the incoming event to a WalkerOS event
         const mappedObj = objToEvent(filterValues(obj), config);
 

packages/sources/datalayer/src/types/index.ts

@@ -9,6 +9,7 @@ declare global {
 export type DataLayer = Array<unknown>;
 export interface Config {
   elb: WalkerOS.Elb | WalkerOS.AnyFunction;
+  filter?: (event: unknown) => boolean;
   mapping?: Mapping;
   name?: string;
   prefix: string;