Function validate

packages/create-webpack-app/src/generators/init/react.ts:78–83

(input: string)

        choices: ["npm", "yarn", "pnpm"],
        default: "npm",
        validate(input: string) {
          if (!input.trim()) {
            return "Package manager cannot be empty";
          }
          return true;
        },
      },
    ],
    actions: function actions(answers: Answers) {