How can you validate user input in a Yeoman prompt?

How can you validate user input in a Yeoman prompt?

• A. Provide a validate function in each prompt object.
• B. Use a shared validator utility.
• C. Validation is not supported in Yeoman prompts.
• D. Validate by checking answers after generation.

Answer: (A)

In Yeoman prompts, you validate input by providing a validate function on each prompt object. This function runs as the user enters their answer and must return true when the input is valid or return a string with an error message to show feedback and block advancing. This per-prompt validation lets you tailor rules for every piece of input—for example, ensuring a non-empty project name, matching a specific pattern, or checking numeric ranges—before the generator proceeds. If you wanted to reuse the same checks, you could extract them into a shared utility, but the standard and most reliable approach is to attach a validate function to each prompt. Validating after generation is not ideal because it won’t prevent the creation of invalid data or files in the first place.

In Yeoman prompts, you validate input by providing a validate function on each prompt object. This function runs as the user enters their answer and must return true when the input is valid or return a string with an error message to show feedback and block advancing. This per-prompt validation lets you tailor rules for every piece of input—for example, ensuring a non-empty project name, matching a specific pattern, or checking numeric ranges—before the generator proceeds. If you wanted to reuse the same checks, you could extract them into a shared utility, but the standard and most reliable approach is to attach a validate function to each prompt. Validating after generation is not ideal because it won’t prevent the creation of invalid data or files in the first place.