8f8f09008a
Track .cursor/rules/ in git so coding conventions are shared across the team. Everything else under .cursor/ stays ignored. Signed-off-by: Émile Ré <emile@probo.com>
47 lines
983 B
Plaintext
47 lines
983 B
Plaintext
---
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description: Go error handling — wrap with fmt.Errorf, always name err, use errors.AsType
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globs: "**/*.go"
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alwaysApply: false
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---
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# Go error handling
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## Wrapping
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- Error variables are always named `err`
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- When a function returns errors from multiple call sites, each must be wrapped
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- Wrap with `fmt.Errorf("cannot ...: %w", err)` — lowercase, starts with `cannot`
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- Each wrap message in a function must be distinct
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```go
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// GOOD
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foo, err := s.loadFoo(ctx)
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if err != nil {
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return fmt.Errorf("cannot load foo: %w", err)
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}
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bar, err := s.loadBar(ctx, foo.ID)
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if err != nil {
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return fmt.Errorf("cannot load bar: %w", err)
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}
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// BAD — bare return without wrapping
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foo, err := s.loadFoo(ctx)
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if err != nil {
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return err
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}
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```
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## Type assertions on errors
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Use `errors.AsType[T](err)` (generic form), not `errors.As(err, &ptr)`:
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```go
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// GOOD
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if e, ok := errors.AsType[*ValidationError](err); ok { ... }
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// BAD
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var ve *ValidationError
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if errors.As(err, &ve) { ... }
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```
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