Production Bugs

Summary The analyzed code snippet implements basic database abstraction functions for a REST API using the mysqli extension. It provides two primary utility functions: one for retrieving data (adatokLekerdezese) and one for modifying data (adatokValtoztatasa). While functional for a local learning environment, the pattern demonstrates significant architectural anti-patterns regarding connection management, security, and error handling … Read more

Summary A common design dilemma arises when designing RESTful endpoints that fetch a single resource: how to represent the absence of data. In this specific case, an endpoint designed to fetch a notification or message returns a structured object when data exists, but the developer is unsure whether to signal “not found” via a 404 … Read more

Summary A production system utilizing Express, express-validator, and i18next failed to provide localized error messages, instead returning a generic “Invalid value” string. While the developer correctly configured the localization middleware, the application architecture introduced a critical race condition during the application bootstrap phase. Root Cause The fundamental issue is a Lifecycle Mismatch between the module … Read more

Summary The developer is struggling with manual data mapping and infrastructure coupling. They are currently using raw ADO.NET to manually iterate through a MySqlDataReader, mapping every single column to a class constructor by index or string name. While this works for a single query, it is highly unscalable, error-prone, and creates a massive amount of … Read more

Summary A Submit Ads form was failing to display newly created advertisements on the homepage. The issue stemmed from a race condition between the Ajax request that creates an ad and the DOM update that appends it to the latest ads list. Key Takeaway: Ensure that UI updates occur only after the server confirms success … Read more

EAS Build Uploads Entire Project Instead of Just Mobile Folder Despite .easignore Summary EAS Build uploaded the entire monorepo (client + server folders) instead of only the mobile project, despite the presence of a .easignore file. The developer had placed .easignore inside the mobile subfolder, expecting it to filter out the server directory. This resulted … Read more

Summary A production-level reinforcement learning simulation failed its validation suite due to a logic error in the environment dynamics and action selection. Specifically, the implementation lacked an epsilon-greedy strategy for exploration, used a hardcoded action (always moving right), and implemented a faulty reward loop at the terminal state. This resulted in the agent converging to … Read more