ENH - clock app

frontend/src/utils/clock.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it } from 'vitest'
 import {
   elapsedMilliseconds,
+  formatStopwatch,
   formatTimer,
   remainingMilliseconds,
   timerPickerMilliseconds,
@@ -18,4 +19,8 @@ describe('timestamp clocks', () => {
     expect(timerPickerValue(3_661_000)).toBe('01:01:01')
     expect(timerPickerMilliseconds('01:01:01')).toBe(3_661_000)
   })
+
+  it('formats stopwatch durations with actual milliseconds', () => {
+    expect(formatStopwatch(61_234)).toBe('01:01.234')
+  })
 })

frontend/src/utils/clock.ts

@@ -18,11 +18,11 @@ export function remainingMilliseconds(
 }
 
 export function formatStopwatch(milliseconds: number): string {
-  const totalCentiseconds = Math.floor(milliseconds / 10)
-  const minutes = Math.floor(totalCentiseconds / 6000)
-  const seconds = Math.floor((totalCentiseconds % 6000) / 100)
-  const centiseconds = totalCentiseconds % 100
-  return `${String(minutes).padStart(2, '0')}:${String(seconds).padStart(2, '0')}.${String(centiseconds).padStart(2, '0')}`
+  const totalMilliseconds = Math.floor(milliseconds)
+  const minutes = Math.floor(totalMilliseconds / 60_000)
+  const seconds = Math.floor((totalMilliseconds % 60_000) / 1000)
+  const millisecondsPart = totalMilliseconds % 1000
+  return `${String(minutes).padStart(2, '0')}:${String(seconds).padStart(2, '0')}.${String(millisecondsPart).padStart(3, '0')}`
 }
 
 export function formatTimer(milliseconds: number): string {