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Error Handling Best Practices

Guidelines for writing robust, maintainable error handling code.

Why this exists​

Consistent error handling patterns make code more reliable and easier to maintain.

How it works​

Follow principles like failing fast, providing context, and using appropriate error types. Prefer explicit error handling over silent failures.

Examples​

# Fail fast with clear messages
fn connectDatabase(url) {
  check url == null {
    throw "Database URL is required"
  }
  check typeof(url) != "string" {
    throw "Database URL must be a string"
  }
  # Attempt connection...
}

# Provide context in errors
fn loadUser(id) {
  try {
    return database.findUser(id)
  } catch error {
    throw "Failed to load user " + id + ": " + error
  }
}

# Use finally for cleanup
fn processFile(path) {
  set handle = null
  try {
    set handle = open(path)
    return parseContent(handle.read())
  } finally {
    check handle != null {
      handle.close()
    }
  }
}

Common mistakes​

  • Catching all errors generically
  • Not cleaning up resources
  • Providing vague error messages