Automatically generate path params definition

[ivan-tymoshenko]

Prerequisites

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• I have searched existing issues to ensure the issue has not already been raised

Issue

It would be nice if @fastify/swagger would generate a default schema for path params.

  fastify.get('/example/*', async (request, reply) => {})

Something like this:

"/{param}": {
  "get": {
    "params": {
      "param": {
        "type": "string"
      }
    },
    "responses": {
      "200": {
        "description": "Default Response"
      }
    }
  }
}

Instead of this:

"/{param}": {
  "get": {
    "responses": {
      "200": {
        "description": "Default Response"
      }
    }
  }
}

[Uzlopak]

I am not sure.

If we do this, the swagger could be correct. But on the other hand, path params schema is not effected by this.

[ivan-tymoshenko]

Sorry, I don't undersand what do you mean

[Uzlopak]

fastify.get('/example/{param}', {schema: { params: {} /* what? */ } }, async (request, reply) => {})

[ivan-tymoshenko]

Oh, I see. Can we resolve it on a fastify level?

[Uzlopak]

idk. I would personally expect that schema gets validated against the path.

[mcollina]

@Uzlopak I don't understand

[Uzlopak]

const paramsJsonSchema = {
  type: 'object',
  required: [
    'par1', 'par2'
  ],
  properties: {
    par1: { type: 'string' },
    par2: { type: 'number' }
  },
  additionalProperties: false
}

fastify.get('/example/{par1}/{par2}', {schema: paramsJsonSchema }, async (request, reply) => {}) // OK
fastify.get('/example/{par1}/{par2}/{invalid}', {schema: paramsJsonSchema }, async (request, reply) => {}) // ERROR: Did not found 'invalid' in schema
fastify.get('/example/{par1}/{par3}', {schema: paramsJsonSchema }, async (request, reply) => {}) // ERROR: Missing parameter 'par2'

[ivan-tymoshenko]

I would say, let's generate default param schema only if user doesn't specify a schema for param at all. If there is something, even with missing params like in your example, we should not modify it.

[Uzlopak]

I agree.

[mcollina]

This would be amazing to have

[msebastianb]

I'd like to pick up this.

[mcollina]

go for it!

[msebastianb]

I think this #761 could be a good way. Let me know otherwise. I'm open to suggestions.