update money tracker

src/lib/money-tracker/charts.test.ts

@@ -1,5 +1,11 @@
 import { describe, expect, it } from 'vitest';
-import { accountBalances, balanceSeries, forecastSeries, utilityEstimate } from './charts';
+import {
+	accountBalances,
+	balanceSeries,
+	forecastSeries,
+	utilityEstimate,
+	wealthProjection
+} from './charts';
 
 describe('money tracker calculations', () => {
 	it('keeps balances separate across accounts and preserves transaction order', () => {
@@ -14,8 +20,43 @@ describe('money tracker calculations', () => {
 		];
 		expect([...accountBalances(accounts, transactions).values()]).toEqual([8500, 25000]);
 		expect(balanceSeries(accounts, transactions)[0].points.map((point) => point.value)).toEqual([
-			10000, 7500, 8500
+			7500, 7500, 8500
 		]);
+		const combined = balanceSeries(accounts, transactions).at(-1)!;
+		expect(combined.label).toBe('All accounts');
+		expect(combined.emphasis).toBeFalsy();
+		expect(combined.points.map((point) => point.value)).toEqual([27500, 32500, 33500]);
+		expect(combined.points.at(-1)?.value).toBe(
+			[...accountBalances(accounts, transactions).values()].reduce((sum, value) => sum + value, 0)
+		);
+	});
+
+	it('plots combined transactions in date order even if the input is unordered', () => {
+		const combined = balanceSeries(
+			[{ id: 1, name: 'Cash', openingBalanceCents: 1000 }],
+			[
+				{ accountId: 1, date: '2026-02-02', amountCents: 200 },
+				{ accountId: 1, date: '2026-01-01', amountCents: -100 }
+			]
+		).at(-1)!;
+		expect(combined.points).toEqual([
+			{ date: '2026-01-01', value: 900 },
+			{ date: '2026-02-02', value: 1100 }
+		]);
+	});
+
+	it('does not show a temporary loss when money moves between accounts on the same date', () => {
+		const combined = balanceSeries(
+			[
+				{ id: 1, name: 'Daily', openingBalanceCents: 1000 },
+				{ id: 2, name: 'Shared', openingBalanceCents: 0 }
+			],
+			[
+				{ accountId: 1, date: '2026-01-01', amountCents: -200 },
+				{ accountId: 2, date: '2026-01-01', amountCents: 200 }
+			]
+		).at(-1)!;
+		expect(combined.points).toEqual([{ date: '2026-01-01', value: 1000 }]);
 	});
 
 	it('projects only future estimates from the current balance', () => {
@@ -32,6 +73,46 @@ describe('money tracker calculations', () => {
 		).toEqual([10000, 7500, 12500]);
 	});
 
+	it('keeps the reserve, transfers excess into investments, and adds growth only to invested money', () => {
+		const settings = {
+			investmentAccountId: 2,
+			reserveCents: 100000,
+			annualReturnPercent: '5.00',
+			contributionMode: 'excess',
+			fixedMonthlyCents: 0,
+			includeRecurring: 1,
+			endDate: '2026-11-30'
+		};
+		const accounts = [
+			{ id: 1, kind: 'spendable', openingBalanceCents: 100000 },
+			{ id: 2, kind: 'investment', openingBalanceCents: 0 }
+		];
+		const series = wealthProjection(
+			accounts,
+			new Map([
+				[1, 100000],
+				[2, 0]
+			]),
+			[{ date: '2026-10-01', accountId: 1, amountCents: -10000 }],
+			[{ date: '2026-10-15', accountId: 1, amountCents: 20000 }],
+			[{ amountCents: 50000, cadence: 'monthly', accountId: 1 }],
+			settings,
+			'2026-09-23'
+		);
+		expect(series[0].points.map((point) => point.value)).toEqual([100000, 100000, 160000, 210244]);
+		expect(series[1].points.at(-1)?.value).toBe(100000);
+		expect(series[2].points.at(-1)?.value).toBe(110244);
+	});
+
+	it('does not add a future dated transaction to today’s starting balance', () => {
+		const accounts = [{ id: 1, kind: 'spendable', openingBalanceCents: 10000 }];
+		const future = [{ date: '2026-10-01', accountId: 1, amountCents: 5000 }];
+		const balances = accountBalances(accounts, []);
+		const series = wealthProjection(accounts, balances, future, [], [], null, '2026-09-23');
+		expect(series[0].points[0].value).toBe(10000);
+		expect(series[0].points.at(-1)?.value).toBe(15000);
+	});
+
 	it('compares estimated usage cost with prorated advances', () => {
 		const result = utilityEstimate(
 			[