Never silently ignore an error, and avoid handling an error (e.g., logging it) and then still returning it. Either handle the error fully or propagate it upward, but not both.
Ignoring errors can lead to hidden bugs that are hard to diagnose. Logging an error and also returning it can result in duplicate logs or confusion about who is responsible for handling it. Each error should be dealt with in one place to maintain clarity and avoid surprises.
Side-by-side examples engineers can pattern-match during review.
data, err := ioutil.ReadFile("config.json")
if err != nil {
log.Println("failed to read file:", err)
return err // error is both logged and returned
}
// ... use datadata, err := ioutil.ReadFile("config.json")
if err != nil {
return fmt.Errorf("cannot read config: %w", err) // propagate with context (or handle fully here)
}
// ... use datadata, err := ioutil.ReadFile("config.json")
if err != nil {
log.Println("failed to read file:", err)
return err // error is both logged and returned
}
// ... use datadata, err := ioutil.ReadFile("config.json")
if err != nil {
return fmt.Errorf("cannot read config: %w", err) // propagate with context (or handle fully here)
}
// ... use dataFrom the same buckets as this rule.
Check if loops use equality operators (== or !=) in termination conditions. These can lead to infinite loops if the condition is never met exactly. Instead, use relational operators like < or > for safer loop termination.