trap

Terminate execution with an error message.

import { trap, IDL, update } from 'azle';

export default class {
    @update([IDL.Text], IDL.Text)
    processInput(input: string): string {
        if (input === '') {
            trap('Input cannot be empty');
        }

        if (input.length > 1000) {
            trap('Input too long: maximum 1000 characters allowed');
        }

        return `Processed: ${input}`;
    }
}

The trap function immediately terminates the current execution with an error message. All state changes made during the current call are rolled back.

Parameters:

• message: Error message to include in the trap (string)

Returns: Never returns (execution stops)

Use Cases:

• Input validation with immediate failure
• Critical error conditions
• Guard clauses for invalid states
• Security-related assertions

Important Notes:

• Stops execution immediately
• Rolls back all state changes from the current call
• Cannot be caught or handled within the same call
• Use judiciously as it terminates the entire call