When a Go struct doesn’t serialize to JSON the way you expect — fields missing entirely, wrong key names, or values that should be omitted but aren’t — the cause is almost always a small detail in how the struct fields or their tags are written, since Go’s JSON package is strict about a few…
Running go mod tidy is supposed to clean up your dependencies, but it can sometimes leave you with a “package not found” error for something that was working fine a moment ago. This usually means Go couldn’t resolve or verify a module it needed, and it’s more often a configuration issue than a genuinely missing…
A foreign key constraint violation in GORM during an insert almost always means you’re trying to save a record that references a parent row which doesn’t exist yet — or one that GORM thinks exists because of how Go’s zero values interact with foreign key fields. The Problem You try to insert a record with…
When a Gin route returns a 404 even though the handler is clearly registered and the path looks correct, the cause is almost always a subtle mismatch between what you registered and what’s actually being requested — Gin’s router is strict about exact matches in ways that aren’t always obvious at a glance. The Problem…
A CORS error between a React Native app and a Gin backend is technically a browser-enforced restriction, but it commonly shows up during development with tools like Expo’s web preview, React Native Web, or when testing endpoints from a browser-based debugger — and the fix on the Gin side is the same regardless of exactly…