Hapijs and Joi: check request parameters with presence: 'forbidden'

Question

My goal is to create an index route for messages. The user should be able to specify some query parameters (i.e. Tags, type), but should not specify others. To clarify:

This is normal:

/posts /posts?tags=food /posts?type=regular&tags=stackoverflow 

This not normal:

 /posts?title=Hello 

This is the hapi pack configuration:

 servers: [ { host: 'localhost', port: 3000, options: { labels: ["api"], validation: { abortEarly: false, presence: 'forbidden' } } } ], 

Pay attention to the presence: forbidden parameter.

This is the route configuration:

 handler: function (request, reply) { Post.find(request.query, function (err, posts) { if(err) { console.log(err); } reply(posts); }); }, validate: { query: { type: Joi.string().optional(), tags: Joi.string().optional() } } 

My idea was that validation should allow any subset of the type and tags parameters (including an empty request). However, after executing any of the allowed queries, I get the following error:

 { "statusCode": 400, "error": "Bad Request", "message": "value is not allowed", "validation": { "source": "query", "keys": [ "value" ] } } 

Why? Of course, there is no key named value . How to make the check correct the way I want it?

Answer 1

If you define a non-type schema object, Joi converts it internally to the object() . So this diagram:

 var schema = { type: Joi.string().optional(), tags: Joi.string().optional() }; 

becomes:

 var schema = Joi.object().keys({ type: Joi.string().optional(), tags: Joi.string().optional() }); 

Since you set the presence value to forbidden in the server settings, it applies to the type of the object, so the scheme becomes:

 var schema = Joi.object().forbidden().keys({ type: Joi.string().optional(), tags: Joi.string().optional() }); 

As you can see, it designates the main object as forbidden, which will not allow any value other than undefined :

 var Joi = require('joi'); var schema = Joi.object().forbidden().keys({ type: Joi.string().optional(), tags: Joi.string().optional() }); var value = {}; Joi.validate(value, schema, { presence: 'forbidden' }, function (err, value) { console.log(err); }); 

It outputs:

 { [ValidationError: value is not allowed] name: 'ValidationError', details: [ { message: 'value is not allowed', path: 'value', type: 'any.unknown' } ], _object: {}, annotate: [Function] } 

So, you need to mark the main object either required or optional to override forbidden :

 validate: { query: Joi.object().required().keys({ type: Joi.string().optional(), tags: Joi.string().optional() }) }