Add a utils spec

Added a utils spec file to test the formattedTime
util function.

app/assets/javascripts/pipelines/stores/test_reports/utils.js

 import { TestStatus } from '~/pipelines/constants';
-import { secondsToMilliseconds } from '~/lib/utils/datetime_utility';
 import { __, sprintf } from '../../../locale';
 
 export function iconForTestStatus(status) {
@@ -15,7 +14,7 @@ export function iconForTestStatus(status) {
 
 export const formattedTime = (seconds = 0) => {
   if (seconds < 1) {
-    const milliseconds = secondsToMilliseconds(seconds);
+    const milliseconds = seconds * 1000;
     return sprintf(__('%{milliseconds}ms'), { milliseconds: milliseconds.toFixed(2) });
   }
   return sprintf(__('%{seconds}s'), { seconds: seconds.toFixed(2) });

spec/frontend/pipelines/test_reports/stores/utils_spec.js

+import { formattedTime } from '~/pipelines/stores/test_reports/utils';
+
+describe('Test reports utils', () => {
+  describe('formattedTime', () => {
+    describe('when time is smaller than a second', () => {
+      it('should return time in milliseconds fixed to 2 decimals', () => {
+        const result = formattedTime(0.4815162342);
+        expect(result).toBe('481.52ms');
+      });
+    });
+
+    describe('when time is equal to a second', () => {
+      it('should return time in seconds fixed to 2 decimals', () => {
+        const result = formattedTime(1);
+        expect(result).toBe('1.00s');
+      });
+    });
+
+    describe('when time is greater than a second', () => {
+      it('should return time in seconds fixed to 2 decimals', () => {
+        const result = formattedTime(4.815162342);
+        expect(result).toBe('4.82s');
+      });
+    });
+  });
+});