news screen enhancement - 1

server/domains/screener/screener.controller.ts

@@ -1,7 +1,7 @@
 import type { FastifyInstance, FastifyRequest } from 'fastify';
 import { ScreenerEngine } from './ScreenerEngine';
 import { CatalystCache, SignalSnapshotRepository } from '../../domains/shared';
-import type { LiveAssetResult, ScreenerResult } from '../../domains/shared';
+import type { DataHealth, LiveAssetResult, ScreenerResult } from '../../domains/shared';
 import { screenSchema } from '../../domains/shared/types/schemas';
 
 export class ScreenerController {
@@ -65,11 +65,48 @@ export class ScreenerController {
     const tickers = (req.body as { tickers: string[] }).tickers.map((t) => t.toUpperCase());
     const results = await this.engine.screenTickers(tickers);
     this.recordSnapshots(results, req);
+    const dataHealth = ScreenerController.assessDataHealth(results);
+    if (dataHealth.degraded) {
+      req.log?.warn?.({ dataHealth }, 'screen batch returned degraded fundamentals data');
+    }
     return {
       ...results,
       STOCK: ScreenerController.serializeAssets(results.STOCK as LiveAssetResult[]),
       ETF: ScreenerController.serializeAssets(results.ETF as LiveAssetResult[]),
       BOND: ScreenerController.serializeAssets(results.BOND as LiveAssetResult[]),
+      dataHealth,
+    };
+  }
+
+  /**
+   * P0.4 data-sanity sentinel — if a large share of screened stocks come back
+   * with null core fundamentals (P/E, ROE), the upstream source has likely
+   * changed schema or is throttling. Surface it loudly instead of letting
+   * everything silently degrade to "No Data" rows.
+   */
+  private static assessDataHealth(results: ScreenerResult): DataHealth {
+    const THRESHOLD = 0.3; // >30% nulls = degraded
+    const MIN_SAMPLE = 3; // don't alarm on tiny batches
+
+    const stocks = results.STOCK as LiveAssetResult[];
+    const metrics = stocks.map(
+      (r) => r.asset.metrics as { peRatio?: number | null; returnOnEquity?: number | null },
+    );
+    const nullPeRatio = metrics.filter((m) => m.peRatio == null).length;
+    const nullRoe = metrics.filter((m) => m.returnOnEquity == null).length;
+    const total = metrics.length;
+
+    const degraded =
+      total >= MIN_SAMPLE && (nullPeRatio / total > THRESHOLD || nullRoe / total > THRESHOLD);
+
+    return {
+      degraded,
+      stocksChecked: total,
+      nullPeRatio,
+      nullRoe,
+      message: degraded
+        ? `${Math.max(nullPeRatio, nullRoe)} of ${total} stocks returned no core fundamentals — data source may be degraded; treat this screen with caution`
+        : null,
     };
   }