Project health chart on LayerChart

Project page gets a Sante chart: daily mean of per-routine health
via computeProjectHealthSeries, ending at the current health score.
Both charts share a HealthChart component built on LayerChart's
AreaChart (time x-axis, fixed 0-100 y-axis, completion dots).

1 files changed, 49 insertions, 0 deletions

diff --git a/src/lib/shared/routine-metrics.test.ts b/src/lib/shared/routine-metrics.test.ts
index ccc06ba..57b8c38 100644
--- a/src/lib/shared/routine-metrics.test.ts
+++ b/src/lib/shared/routine-metrics.test.ts
@@ -3,6 +3,7 @@ import {
 	computeRoutineState,
 	computeHealthScore,
 	computeHealthSeries,
+	computeProjectHealthSeries,
 	parseIntervalToDays,
 } from './routine-metrics';
 
@@ -125,6 +126,54 @@ describe('computeHealthSeries', () => {
 	});
 });
 
+describe('computeProjectHealthSeries', () => {
+	it('is empty with no routines', () => {
+		expect(computeProjectHealthSeries([], [], Date.parse(CREATED))).toEqual([]);
+	});
+
+	it('averages per-routine health and ends at the current score', () => {
+		const second = { ...routine, id: 2, name: 'read' };
+		const doneAt = Date.parse(CREATED) + 5 * DAY_MS;
+		const now = Date.parse(CREATED) + 8 * DAY_MS;
+		const series = computeProjectHealthSeries(
+			[routine, second],
+			[{ routineId: 2, doneAt: new Date(doneAt).toISOString() }],
+			now,
+		);
+		const states = [
+			computeRoutineState(routine, [], now),
+			computeRoutineState(
+				second,
+				[{ routineId: 2, doneAt: new Date(doneAt).toISOString() }],
+				now,
+			),
+		];
+		const last = series[series.length - 1];
+		expect(last.at).toBe(now);
+		expect(last.health).toBe(computeHealthScore(states));
+	});
+
+	it('only counts routines alive that day', () => {
+		const late = {
+			...routine,
+			id: 2,
+			name: 'latecomer',
+			createdAt: new Date(Date.parse(CREATED) + 10 * DAY_MS).toISOString(),
+		};
+		const now = Date.parse(CREATED) + 11 * DAY_MS;
+		const series = computeProjectHealthSeries([routine, late], [], now);
+		const beforeLate = series.find(
+			(p) => p.at === Date.parse(CREATED) + 5 * DAY_MS,
+		);
+		const single = computeHealthSeries(
+			routine,
+			[],
+			Date.parse(CREATED) + 5 * DAY_MS,
+		);
+		expect(beforeLate?.health).toBe(single[single.length - 1].health);
+	});
+});
+
 describe('parseIntervalToDays', () => {
 	it('converts units to days', () => {
 		expect(parseIntervalToDays('1d')).toBe(1);