Software Development

In Go, using a mutex with defer might seem like an elegant and safe way to manage your code by ensuring resources are properly released. However, a common mistake lurks when this pattern is used inside loops. When working with mutexes, never do this: func broadcast(ctx context.Context, msgCh <-chan Message) { for { select { case msg := <-msgCh: s.mu.Lock() defer s.mu.Unlock() // ❌ Avoid this // Use the shared resource here case <-ctx.Done(): return } } } This seemingly harmless pattern can cause unexpected behavior and should be avoided. Let’s look into why this happens and how to handle it correctly. ...

When designing Go APIs, you might think it’s harmless to return (nil, nil) when an object isn’t found. Many developers do this because it feels like “not found” shouldn’t be treated as an error. However, this approach often leads to one of the most frustrating runtime crashes in Go: panic: invalid memory address or nil pointer dereference In this post, we’ll cover: The problem — how (nil, nil) breeds fragile code Why this design creates real-world headaches Two solutions: Best practice (recommended): return a predefined error instead Alternative pattern: use an explicit existence flag An evolved, safer version of the code The goal isn’t just to fix mistakes, but to enhance API design to prevent misuse down the line. ...

Introduction For many Go developers, a recurring challenge has been: “What is the right way to handle multiple errors?” Whether it’s running several cleanup steps, processing batches of data, or validating various inputs, ensuring errors are handled correctly and efficiently has been crucial. Before Go 1.20, developers did not have a unified approach; each team created its own solution, often leading to awkward, unidiomatic, or even incorrect patterns. With Go 1.20, we now have a standard, pragmatic solution: errors.Join. This article will explore why older techniques were problematic, how the Go team designed a better approach, and how to apply this new solution effectively in your code. ...