Improvement to work with Joi validator

[Embraser01]

Prerequisites

Please answer the following questions for yourself before submitting an issue.

• [x] I am running the latest version
• [x] I checked the documentation and found no answer
• [x] I checked to make sure that this issue has not already been filed
• [x] I'm reporting the issue to the correct repository

Expected Behavior

When I want to use Joi as validator inside a single node containing the API GW and internal nodes, I can't query internal nodes correctly.

Current Behavior

It fails validation

GET http://localhost:3000/api/v2/~node/actions?withServices=true&onlyAvailable=false

HTTP/1.1 422 Unprocessable Entity
X-Powered-By: Express
Content-type: application/json; charset=utf-8
Date: Sun, 18 Nov 2018 18:38:33 GMT
Connection: keep-alive
Transfer-Encoding: chunked

{
  "name": "ValidationError",
  "message": "child \"onlyAvailable\" fails because [\"onlyAvailable\" must be an object]",
  "code": 422,
  "type": "VALIDATION_ERROR",
  "data": [
    {
      "message": "\"onlyAvailable\" must be an object",
      "path": [
        "onlyAvailable"
      ],
      "type": "object.base",
      "context": {
        "key": "onlyAvailable",
        "label": "onlyAvailable"
      }
    }
  ]
}

Response code: 422 (Unprocessable Entity); Time: 49ms; Content length: 423 bytes

Failure Information

This bug happend because the validator for $node.list look like this and isn't a Joi schema (of course):

https://github.com/moleculerjs/moleculer/blob/2071fcf3ff8d54416b351312921dc184e22db58f/src/internals.js#L15-L25

The only solution I see is to create another ServiceBroker with the fastest-validator but I don't want to handle multiple nodes for now (I'm just starting with moleculer, it's awesome 🎉).

Is there a way to override the validator on a per service base?

Steps to Reproduce

Please provide detailed steps for reproducing the issue.

1. Create a ServiceBroker with a Joi Validator (from the doc example)
2. Launch an API GW in it
3. Request to GET http://localhost:3000/api/v2/~node/actions?withServices=true&onlyAvailable=false
4. You should get an error of validation

Reproduce code snippet

class JoiValidator extends BaseValidator {
  constructor() {
    super();
    // eslint-disable-next-line global-require
    this.validator = require('joi');
  }

  compile(schema) {
    return params => this.validate(params, schema);
  }

  validate(params, schema) {
    const { error } = this.validator.validate(params, schema);
    if (error) throw new ValidationError(error.message, null, error.details);

    return true;
  }
}

const broker = new ServiceBroker({
    logger: console,
    transporter: "NATS",
    validation: true,
    validator: new JoiValidator(),
});

broker.createService({
    name: "test",
    mixins: [ApiGateway],
    settings: {
	    middleware: true,
	
	    routes: [{	
	      // Will also fail if the validator is strict (icebob/fastest-validator#11) ?
	      mergeParams: false,
	
	      // List all routes
	      aliases: {
	        'REST stock-events': 'stock-events',
	      },
	    }],
	}
});

Context

Please provide any relevant information about your setup. This is important in case the issue is not reproducible except for under certain conditions.

• Moleculer version: v0.13.4
• NodeJS version: LTS
• Operating System: Windows 10

Failure Logs

See request upper.

[icebob]

Currently, I don't know, how we can resolve it. A workaround:

• disable internalServices in broker options
• copy the source of $node service
• change the params to Joi & load this new $node service with your others.

[Embraser01]

Ok thanks!

I did manage to create a workaround who will use Joi only if the schema is from Joi:

const Joi = require('joi');
const BaseValidator = require('moleculer').Validator;
const { ValidationError } = require('moleculer').Errors;

class JoiValidator extends BaseValidator {
  compile(schema) {
    if (schema.isJoi) {
      return params => this.validate(params, schema);
    }
    return this.validator.compile(schema);
  }

  // eslint-disable-next-line class-methods-use-this
  validate(params, schema) {
    const { error } = Joi.validate(params, schema);
    if (error) throw new ValidationError(error.message, null, error.details);

    return true;
  }
}

module.exports = JoiValidator;

This add a restriction on the way the params are declared. It must be declared using this syntax:

params: Joi.object({
	paramA: Joi.string().required(),
	paramB: Joi.string(),
}),

// This will not work anymore
params: {
	paramA: Joi.string().required(),
	paramB: Joi.string(),
},

Also the isJoi is not declared in Joi's API except for Errors but do exist in any Joi's object.

There is also the circular problem when listing actions (localhost:3000/api/~node/actions) (cf. #191) because action list contains the Joi schema (which is not safe).

The last problem I saw was the mergeParams problem. Because the params structure changes, but other service don't know that. In this case, your workaround does fix this 😃

As I see it, validators may be on a Service instead of a ServiceBroker. Because in the case I use a service as a library like https://github.com/designtesbrot/moleculer-vault, I will have the same problem except if I launch it in antoher ServiceBroker.

Of course I just started learning all this so I could have missed a lot of concept 😄.

[Embraser01]

Following problems with Joi, I had to adapt the validator in order to work:

The example in the documentation may not work all the time because

• It does not handle other form of validation (used in internal services for example)
• Joi schemas are not cloned correctly by lodash so it will not be able to validate (specially in mixins I think)

So I had to create a (not so nice) workaround to handle this:

const Joi = require('joi');
const BaseValidator = require('moleculer').Validator;
const { ValidationError } = require('moleculer').Errors;

class JoiValidator extends BaseValidator {
  compile(schema) {
    // Need to use a function because Joi schemas are not cloneable
    // The workaround might be dirty but should works
    if (typeof schema === 'function') {
      // Precompile schema to improve performances
      const compiledSchema = Joi.compile(schema());
      return params => this.validate(params, compiledSchema);
    }
    return this.validator.compile(schema);
  }

  // eslint-disable-next-line class-methods-use-this
  validate(params, schema) {
    const { error } = Joi.validate(params, schema);
    if (error) throw new ValidationError(error.message, null, error.details);

    return true;
  }
}

module.exports = JoiValidator;

Then to use in actions:

module.exports = {
	name: 'service',
	actions: {
		list: {
			// Use Joi validator inside an arrow function
			params: () => Joi.object({page: Joi.number().integer().required()}),
			async handler(ctx) {...}
		},
		get: {
			// Can still use fastest-validator
			params: { id: {type: 'number', optional: false}},
			async handler(ctx) {..}
		}
	}
}

It could be nice to change the joi example in the documentation to handle these problems or put a note explaining the edge cases of the example 😃