I Analyzed 500 AI Coding Mistakes and Built an ESLint Plugin to Catch Them

Here's a pattern you've probably seen: const results = items. map ( async ( item ) => { return await fetchItem ( item ); }); Looks fine, right? Your AI assistant wrote it. Tests pass. Then production hits, and results is an array of Promises - not the values you expected. The await on line 2 does nothing. You needed Promise.all(items.mapor a for. of loop. This isn't a TypeScript bug. It's a common LLM coding mistake - one of hundreds I found when I started researching AI-generated code quality.