feat(stats): show work and time-off lengths (#66)

src/app/services/leave-planner.service.spec.ts

@@ -48,6 +48,129 @@ async function runInNonBrowser(request: Parameters<typeof planLeave>[0]) {
 beforeEach(() => vi.setSystemTime(new Date('2024-01-01T12:00:00Z')));
 afterEach(() => vi.useRealTimers());
 
+describe('calculated work-sequence and time-off-period statistics', () => {
+	it('keeps fractional work means and merges consecutive declared days across a weekend', async () => {
+		const result = isPlan(
+			await runInNonBrowser({
+				horizon: { start: '2024-01-02', end: '2024-01-11' },
+				balances: [],
+				rules: [],
+				declaredDays: ['2024-01-05', '2024-01-08'].map((date) => ({
+					date,
+					type: 'other',
+				})),
+			}),
+		);
+		expect(result.metrics).toMatchObject({
+			nonWorkingDayGain: 2,
+			averageWorkSequence: 2.5,
+			longestWorkSequence: 3,
+			averageTimeOffPeriod: 4,
+			longestTimeOffPeriod: 4,
+		});
+	});
+
+	it.each([
+		{
+			scenario: 'averages the 10, 5 and 15 working days including both horizon edges',
+			horizon: { start: '2024-01-08', end: '2024-02-21' },
+			declaredDates: ['2024-01-22', '2024-01-30'],
+			metrics: {
+				averageWorkSequence: 10,
+				longestWorkSequence: 15,
+				averageTimeOffPeriod: 2,
+				longestTimeOffPeriod: 3,
+				nonWorkingDayGain: 2,
+			},
+		},
+		{
+			scenario: 'keeps the unrounded mean of work sequences of 3, 1 and 6 days',
+			horizon: { start: '2024-01-02', end: '2024-01-18' },
+			declaredDates: ['2024-01-05', '2024-01-09'],
+			metrics: {
+				averageWorkSequence: 10 / 3,
+				longestWorkSequence: 6,
+				averageTimeOffPeriod: 2,
+				longestTimeOffPeriod: 3,
+				nonWorkingDayGain: 2,
+			},
+		},
+		{
+			scenario: 'averages one-day and two-day breaks without adding zero-length work samples',
+			horizon: { start: '2024-01-02', end: '2024-01-12' },
+			declaredDates: ['2024-01-03', '2024-01-09', '2024-01-10'],
+			metrics: {
+				averageWorkSequence: 5 / 3,
+				longestWorkSequence: 3,
+				averageTimeOffPeriod: 1.5,
+				longestTimeOffPeriod: 2,
+				nonWorkingDayGain: 0,
+			},
+		},
+		{
+			scenario: 'does not count or split work on intervening holidays and weekends',
+			horizon: { start: '2024-05-06', end: '2024-05-15' },
+			declaredDates: [],
+			metrics: {
+				averageWorkSequence: 5,
+				longestWorkSequence: 5,
+				averageTimeOffPeriod: null,
+				longestTimeOffPeriod: null,
+				nonWorkingDayGain: 0,
+			},
+		},
+		{
+			scenario:
+				'retains an empty work average and a measured zero when every workday is declared',
+			horizon: { start: '2024-01-08', end: '2024-01-13' },
+			declaredDates: ['2024-01-08', '2024-01-09', '2024-01-10', '2024-01-11', '2024-01-12'],
+			metrics: {
+				averageWorkSequence: null,
+				longestWorkSequence: 0,
+				averageTimeOffPeriod: 9,
+				longestTimeOffPeriod: 9,
+				nonWorkingDayGain: 4,
+			},
+		},
+		{
+			scenario: 'distinguishes no samples from zero gain in a weekend-only horizon',
+			horizon: { start: '2024-01-06', end: '2024-01-08' },
+			declaredDates: [],
+			metrics: {
+				averageWorkSequence: null,
+				longestWorkSequence: 0,
+				averageTimeOffPeriod: null,
+				longestTimeOffPeriod: null,
+				nonWorkingDayGain: 0,
+			},
+		},
+		{
+			scenario:
+				'counts Christmas on a Saturday once alongside its Sunday in a declared break',
+			horizon: { start: '2021-12-20', end: '2021-12-28' },
+			declaredDates: ['2021-12-24'],
+			metrics: {
+				averageWorkSequence: 2.5,
+				longestWorkSequence: 4,
+				averageTimeOffPeriod: 3,
+				longestTimeOffPeriod: 3,
+				nonWorkingDayGain: 2,
+			},
+		},
+	])('$scenario', async ({ horizon, declaredDates, metrics }) => {
+		const result = isPlan(
+			await runInNonBrowser({
+				horizon,
+				balances: [],
+				rules: [],
+				declaredDays: declaredDates.map((date) => ({ date, type: 'other' })),
+			}),
+		);
+		expect(result.placements).toEqual([]);
+		expect(result.metrics).toMatchObject(metrics);
+	});
+});
+
 describe('declared holiday patterns and captured entitlement date', () => {
 	const producer = {
 		id: 'producer',
@@ -1214,7 +1337,13 @@ describe('planLeave', () => {
 				nonWorkingDayGain: 2,
 			},
 		]);
-		expect(result.metrics).toMatchObject({ nonWorkingDayGain: 2, longestWorkSequence: 3 });
+		expect(result.metrics).toMatchObject({
+			nonWorkingDayGain: 2,
+			averageWorkSequence: 2,
+			longestWorkSequence: 3,
+			averageTimeOffPeriod: 3,
+			longestTimeOffPeriod: 3,
+		});
 	});
 
 	it('merges declarations, placements, weekends and national holidays without counting dates twice', async () => {
@@ -1254,7 +1383,14 @@ describe('planLeave', () => {
 				nonWorkingDayGain: 6,
 			},
 		]);
-		expect(result.metrics).toMatchObject({ nonWorkingDayGain: 6, holidayWeekValue: 5 });
+		expect(result.metrics).toMatchObject({
+			nonWorkingDayGain: 6,
+			holidayWeekValue: 5,
+			averageWorkSequence: null,
+			longestWorkSequence: 0,
+			averageTimeOffPeriod: 10,
+			longestTimeOffPeriod: 10,
+		});
 	});
 
 	it('uses declared days to split work sequences while weekends and holidays alone never split them', async () => {
@@ -1319,6 +1455,13 @@ describe('planLeave', () => {
 			declaredDates: ['2024-01-02', '2024-01-03', '2024-01-05'],
 			nonWorkingDayGain: 5,
 		});
+		expect(result.metrics).toMatchObject({
+			nonWorkingDayGain: 5,
+			averageWorkSequence: null,
+			longestWorkSequence: 0,
+			averageTimeOffPeriod: 9,
+			longestTimeOffPeriod: 9,
+		});
 		const unanchored = isPlan(
 			await runInNonBrowser({
 				horizon: selectedHorizon,
@@ -1328,7 +1471,13 @@ describe('planLeave', () => {
 			}),
 		);
 		expect(unanchored.timeOffPeriods).toEqual([]);
-		expect(unanchored.metrics.nonWorkingDayGain).toBe(0);
+		expect(unanchored.metrics).toMatchObject({
+			nonWorkingDayGain: 0,
+			averageWorkSequence: 2,
+			longestWorkSequence: 2,
+			averageTimeOffPeriod: null,
+			longestTimeOffPeriod: null,
+		});
 	});
 
 	it.each([