fix(stats): compute average fee and total fees only across sent transactions (#58)

src/components/dashboard/QuickStats.test.tsx

@@ -0,0 +1,72 @@
+import React from 'react'
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+import { render, screen } from '@testing-library/react'
+import { QuickStats } from './QuickStats'
+import { useRecentTransactions } from '@/hooks/useTransactions'
+import { Transaction } from '@/types'
+
+vi.mock('@/hooks/useTransactions', () => ({
+  useRecentTransactions: vi.fn(),
+}))
+
+function makeTx(overrides: Partial<Transaction> = {}): Transaction {
+  return {
+    id: 'tx-1',
+    hash: 'hash-1',
+    createdAt: new Date().toISOString(),
+    type: 'payment',
+    status: 'success',
+    sourceAccount: 'GBBD47IF6LWK7P7MDEVSCWR7DPUWV3NY3DTQEVFL4NAT4AQH3ZLLFLA5',
+    destinationAccount: 'GAHK7WOJWVU67MHUCHC5QUODIC2GQUQ32ZPXRKZ43D4ML5I5U2PLM6TV',
+    amount: '10',
+    assetCode: 'XLM',
+    assetIssuer: null,
+    fee: '100',
+    ledger: 1000,
+    direction: 'sent',
+    counterparty: 'GAHK7WOJWVU67MHUCHC5QUODIC2GQUQ32ZPXRKZ43D4ML5I5U2PLM6TV',
+    memo: '',
+    ...overrides,
+  }
+}
+
+describe('QuickStats', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('computes average fee using only sent transactions, ignoring received transaction fees', () => {
+    // 1 sent transaction with fee = 100 stroops (0.0000100 XLM)
+    // 1 received transaction with massive fee = 10_000_000 stroops (1.0 XLM)
+    const transactions = [
+      makeTx({ id: 'tx-1', direction: 'sent', fee: '100', amount: '50' }),
+      makeTx({ id: 'tx-2', direction: 'received', fee: '10000000', amount: '100' }),
+    ]
+
+    vi.mocked(useRecentTransactions).mockReturnValue({
+      data: { transactions, total: 2 },
+      isLoading: false,
+    } as any)
+
+    render(<QuickStats />)
+
+    // Expected avg fee = 100 / 1 / 10_000_000 = 0.0000100
+    expect(screen.getByText('0.0000100')).toBeInTheDocument()
+    expect(screen.getByText('Average Fee')).toBeInTheDocument()
+  })
+
+  it('handles zero sent transactions gracefully with avgFee = "0"', () => {
+    const transactions = [
+      makeTx({ id: 'tx-1', direction: 'received', fee: '5000', amount: '20' }),
+    ]
+
+    vi.mocked(useRecentTransactions).mockReturnValue({
+      data: { transactions, total: 1 },
+      isLoading: false,
+    } as any)
+
+    render(<QuickStats />)
+
+    expect(screen.getByText('0')).toBeInTheDocument()
+  })
+})

src/components/dashboard/QuickStats.tsx

@@ -20,10 +20,10 @@ export function QuickStats() {
     .reduce((sum, t) => sum + parseFloat(t.amount || '0'), 0)
     .toFixed(4)
 
-  const avgFee = transactions.length
+  const avgFee = sent.length
     ? (
-        transactions.reduce((s, t) => s + parseFloat(t.fee || '0'), 0) /
-        transactions.length /
+        sent.reduce((s, t) => s + parseFloat(t.fee || '0'), 0) /
+        sent.length /
         10_000_000
       ).toFixed(7)
     : '0'

src/pages/History.tsx

@@ -38,9 +38,12 @@ function HistoryChart() {
       day: 'numeric',
     })
     if (days[key]) {
-      if (tx.direction === 'sent') days[key].sent += parseFloat(tx.amount || '0')
-      else days[key].received += parseFloat(tx.amount || '0')
-      days[key].fees += parseFloat(tx.fee || '0') / 10_000_000
+      if (tx.direction === 'sent') {
+        days[key].sent += parseFloat(tx.amount || '0')
+        days[key].fees += parseFloat(tx.fee || '0') / 10_000_000
+      } else {
+        days[key].received += parseFloat(tx.amount || '0')
+      }
     }
   })
 
@@ -102,9 +105,10 @@ function HistorySummary() {
   const { data } = useRecentTransactions(50)
   const txs = data?.transactions ?? []
 
-  const totalSent = txs.filter((t) => t.direction === 'sent').reduce((s, t) => s + parseFloat(t.amount || '0'), 0)
+  const sentTxs = txs.filter((t) => t.direction === 'sent')
+  const totalSent = sentTxs.reduce((s, t) => s + parseFloat(t.amount || '0'), 0)
   const totalReceived = txs.filter((t) => t.direction === 'received').reduce((s, t) => s + parseFloat(t.amount || '0'), 0)
-  const totalFees = txs.reduce((s, t) => s + parseFloat(t.fee || '0') / 10_000_000, 0)
+  const totalFees = sentTxs.reduce((s, t) => s + parseFloat(t.fee || '0') / 10_000_000, 0)
   const successRate = txs.length
     ? Math.round((txs.filter((t) => t.status === 'success').length / txs.length) * 100)
     : 100