| name | go-expert |
| description | Go gotchas and decision criteria. Covers error handling patterns, concurrency pitfalls, and interface design. |
| autoInvoke | false |
| priority | high |
| triggers | ["golang","go","gin","echo","fiber"] |
| paths | ["**/*.go","go.mod","go.sum"] |
| allowed-tools | Read, Grep, Glob, Edit, Write |
| user-invocable | false |
AI-consumed reference. Optimized for Claude to read during execution.
Human-readable explanation: see docs/architecture/HIERARCHICAL_PLANNING.md
or docs/getting-started/ depending on topic.
Go Expert — Gotchas & Decisions
Use Context7 for Go framework docs.
Key Decisions
decisions[4]{choice,use_when}:
Gin vs Echo vs Fiber,"Gin: most popular/stable. Echo: cleaner API. Fiber: highest perf (Express-like)"
Interface location,"Define in CONSUMER package not provider. Accept interfaces return structs"
Channel vs Mutex,"Channel for communication between goroutines. Mutex for protecting shared memory"
Table-driven vs subtests,"Table-driven for input variations. Subtests (t.Run) for distinct scenarios"
Gotchas
err != nil check EVERY error return — never ignore with _%w for wrapping errors (unwrappable), %v for formatting only (not unwrappable)- Goroutine leak: always ensure goroutines can exit (context cancellation, done channels)
defer evaluates args immediately but executes LIFO — defer f.Close() captures current f- Range loop variable reuse (pre-Go 1.22):
for _, v := range items { go func() { use(v) }() } captures same v. Fixed in Go 1.22+
nil slice vs empty slice: var s []int (nil, marshals to null) vs s := []int{} (empty, marshals to [])context.Background() for top-level, context.TODO() as placeholder. Always pass context as first param- Race conditions: use
-race flag in tests. go test -race ./...
sync.WaitGroup: Add() before goroutine launch, not inside it
