Fix generator randomBoolean() to ensure it works with seeded random…

… numbers

x-pack/plugins/security_solution/common/endpoint/data_generators/base_data_generator.ts

@@ -18,6 +18,7 @@ const DAY_OFFSETS = Array.from({ length: 14 }, (_, i) => 8.64e7 * (i + 1));
  * public method named `generate()` which should be implemented by sub-classes.
  */
 export class BaseDataGenerator<GeneratedDoc extends {} = {}> {
+  /** A javascript seeded random number (float between 0 and 1). Don't use `Math.random()` */
   protected random: seedrandom.prng;
 
   constructor(seed: string | seedrandom.prng = Math.random().toString()) {
@@ -49,7 +50,7 @@ export class BaseDataGenerator<GeneratedDoc extends {} = {}> {
 
   /** Generate either `true` or `false` */
   protected randomBoolean(): boolean {
-    return Math.random() < 0.5;
+    return this.random() < 0.5;
   }
 
   /** generate random OS family value */

x-pack/plugins/security_solution/common/endpoint/generate_data.test.ts

@@ -87,7 +87,9 @@ describe('data generator', () => {
     expect(event2.event?.sequence).toBe((firstNonNullValue(event1.event?.sequence) ?? 0) + 1);
   });
 
-  it('creates the same documents with same random seed', () => {
+  // Lets run this one multiple times just to ensure that the randomness
+  // is truly predicable based on the seed passed
+  it.each([1, 2, 3, 4, 5])('[%#] creates the same documents with same random seed', () => {
     const generator1 = new EndpointDocGenerator('seed');
     const generator2 = new EndpointDocGenerator('seed');
     const timestamp = new Date().getTime();