phase-1: optimize code

src/analyst/CatalystAnalyst.js

@@ -5,15 +5,16 @@ const MAX_STORIES = 15;
 const TICKER_REGEX = /^[A-Z]{1,6}$/;
 
 export class CatalystAnalyst {
-  constructor() {
+  constructor({ logger } = {}) {
     this.client = new YahooClient();
+    this.logger = logger ?? { write: (msg) => process.stdout.write(msg) };
   }
 
   async run() {
-    process.stdout.write('🔍 Fetching market news...');
+    this.logger.write('🔍 Fetching market news...');
     const stories = await this._fetchNews();
     const tickers = this._extractTickers(stories);
-    process.stdout.write(` ${stories.length} stories, ${tickers.length} tickers\n`);
+    this.logger.write(` ${stories.length} stories, ${tickers.length} tickers\n`);
     return { tickers, stories };
   }