fix: count brokerage cash once and skip short-position return percent (WealthLedger/backend#140)

src/modules/investments/portfolio/domain/portfolio-structure.spec.ts

@@ -19,7 +19,7 @@ const position = (
 });
 
 describe('portfolio structure', () => {
-  it('includes cash once and keeps currency instruments among other assets', () => {
+  it('counts cash once and skips CURRENCY positions that mirror it', () => {
     const result = portfolioStructure(
       [
         position('STOCK', '60'),
@@ -30,13 +30,13 @@ describe('portfolio structure', () => {
     );
     expect(result.currencies[0]).toEqual({
       currency: 'RUB',
-      totalValue: '100',
+      totalValue: '90',
       hasNegativeValues: false,
       categories: [
-        { type: 'STOCK', value: '60', sharePercent: '60' },
-        { type: 'BOND', value: '20', sharePercent: '20' },
-        { type: 'OTHER', value: '10', sharePercent: '10' },
-        { type: 'CASH', value: '10', sharePercent: '10' },
+        { type: 'STOCK', value: '60', sharePercent: '66.666667' },
+        { type: 'BOND', value: '20', sharePercent: '22.222222' },
+        { type: 'OTHER', value: '0', sharePercent: '0' },
+        { type: 'CASH', value: '10', sharePercent: '11.111111' },
       ],
     });
   });

src/modules/investments/portfolio/domain/portfolio-structure.ts

@@ -43,6 +43,8 @@ export function portfolioStructure(
     currencies.set(money.currency, group);
   };
   for (const position of positions) {
+    // CURRENCY positions mirror cash, which is counted once as CASH below.
+    if (position.type === 'CURRENCY') continue;
     const type = ['BOND', 'STOCK'].includes(position.type)
       ? position.type
       : 'OTHER';