phase-1: optimize code

tests/DataMapper.test.js

@@ -78,6 +78,63 @@ test('FCF yield is computed when data available', () => {
   assert(result.fcfYield > 0);
 });
 
+test('peRatio prefers trailingPE over forwardPE', () => {
+  // trailingPE=30 in summaryDetail, forwardPE=28 in defaultKeyStatistics
+  const result = mapToStandardFormat('AAPL', base);
+  assert.equal(result.peRatio, 30); // trailing should win
+});
+
+test('negative FCF yield is preserved, not nulled', () => {
+  const negativeFcf = {
+    ...base,
+    financialData: { ...base.financialData, freeCashflow: -2e9 },
+  };
+  const result = mapToStandardFormat('AAPL', negativeFcf);
+  assert.notEqual(result.fcfYield, null);
+  assert(result.fcfYield < 0, 'negative FCF should produce negative yield, not null');
+});
+
+test('ETF maps volume from summaryDetail', () => {
+  const etfSummary = {
+    ...base,
+    price: { ...base.price, quoteType: 'ETF' },
+    assetProfile: { category: 'Large Blend' },
+    summaryDetail: {
+      ...base.summaryDetail,
+      averageVolume: 5000000,
+      expenseRatio: 0.0003,
+      trailingAnnualDividendYield: 0.013,
+    },
+    defaultKeyStatistics: { fiveYearAverageReturn: 0.12 },
+  };
+  const result = mapToStandardFormat('VOO', etfSummary);
+  assert.equal(result.volume, 5000000);
+});
+
+test('bond duration inferred from category — intermediate maps to 5y', () => {
+  const bondSummary = {
+    ...base,
+    price: { ...base.price, quoteType: 'ETF' },
+    assetProfile: { category: 'Intermediate-Term Bond' },
+    summaryDetail: { yield: 0.045 },
+    defaultKeyStatistics: {},
+  };
+  const result = mapToStandardFormat('BND', bondSummary);
+  assert.equal(result.duration, 5);
+});
+
+test('bond duration inferred from category — short-term maps to 2y', () => {
+  const bondSummary = {
+    ...base,
+    price: { ...base.price, quoteType: 'ETF' },
+    assetProfile: { category: 'Short-Term Bond' },
+    summaryDetail: { yield: 0.05 },
+    defaultKeyStatistics: {},
+  };
+  const result = mapToStandardFormat('SHY', bondSummary);
+  assert.equal(result.duration, 2);
+});
+
 test('metrics are null (not 0) when data missing', () => {
   const sparse = {
     price: { quoteType: 'EQUITY', regularMarketPrice: 100 },