refactor. migrated date_utils file to typescript, add tests

webapp/src/utils/date_utils.test.ts

@@ -0,0 +1,49 @@
+import {beforeAll, describe, expect, it, jest} from "@jest/globals";
+import {formatTimeSince} from "./date_utils";
+
+
+describe('formatTimeSince should work as expected', () => {
+
+    beforeAll(() => {
+        const mockCurrentDate = new Date("December 17, 1995 10:11:00");
+        jest.spyOn(Date, 'now').mockReturnValue(mockCurrentDate.getTime());
+    })
+
+    it.each([
+        {
+            dateString: 'December 17, 1995 10:10:30',
+            output: '30 seconds'
+        },
+        {
+            dateString: 'December 17, 1995 10:10:59',
+            output: '1 second'
+        },
+        {
+            dateString: 'December 17, 1995 09:41:00',
+            output: '30 minutes'
+        },
+        {
+            dateString: 'December 17, 1995 10:10:00',
+            output: '1 minute'
+        },
+        {
+            dateString: 'December 17, 1995 06:11:00',
+            output: '4 hours'
+        },
+        {
+            dateString: 'December 17, 1995 09:11:00',
+            output: '1 hour'
+        },
+        {
+            dateString: 'December 13, 1995 10:11:00',
+            output: '4 days'
+        },
+        {
+            dateString: 'December 16, 1995 10:11:00',
+            output: '1 day'
+        },
+    ])('should show time since current time in proper format', ({dateString, output}) => {
+        const result = formatTimeSince(dateString);
+        expect(result).toBe(output)
+    });
+})

webapp/src/utils/date_utils.ts

@@ -0,0 +1,17 @@
+export function formatTimeSince(date: string): string {
+    const pastDateInSeconds = new Date(date).getTime();
+    const secondsSince = Math.trunc((Date.now() - pastDateInSeconds) / 1000);
+    if (secondsSince < 60) {
+        return `${secondsSince} ${secondsSince === 1 ? 'second' : 'seconds'}`;
+    }
+    const minutesSince = Math.trunc(secondsSince / 60);
+    if (minutesSince < 60) {
+        return `${minutesSince} ${minutesSince === 1 ? 'minute' : 'minutes'}`;
+    }
+    const hoursSince = Math.trunc(minutesSince / 60);
+    if (hoursSince < 24) {
+        return `${hoursSince} ${hoursSince === 1 ? 'hour' : 'hours'}`;
+    }
+    const daysSince = Math.trunc(hoursSince / 24);
+    return `${daysSince} ${daysSince === 1 ? 'day' : 'days'}`;
+}