How to check for a presence of at least one parameter using express-validator

Question

I'm using express and express-validator in my Nodejs app. I want to check for the presence of at least one of incoming parameters. Its sort of either or combination.

Lets say my service accepts 2 parameters. I want to be sure at least one of them is provided by the client.

The below code would work for just one. But I have no idea how to make it either or.

req.checkBody('param1', 'Mandatory field param1 not populated').notEmpty();

Answer 1

Say you want to update a model that has id, status, and content... like a social media post, for example. Your controller may support updating the status of the model or its content. So, you could do something like the following:

export const updateModelValidation = [
    param('id').exists().isNumeric(), // <-- required model identifier
    oneOf( // <-- one of the following must exist
        [
          body('status').exists().isString(),
          body('content').exists().isString(),
        ],
    ),
];

Answer 2

You could use multiple validation chains and use the oneOf function to validate against at least 1 validation chain.

https://www.npmjs.com/package/express-validator#oneofvalidationchains-message