Singular params with Array[String] in body does not render correct JSON

[bobbytables]

I hit a bug when trying to use this param declaration:

params do
  requires :tags, type: Array[String], documentation: { in: 'body' }
end

Expecting this to create a schema and tag it on the request, it actually did a formData instead:

{
  "in": "formData",
  "name": "tags",
  "type": "array",
  "items": {
    "type": "string"
  },
  "required": true
}

I've been using this successfully everywhere else so this threw me off. I experimented and realized that the requires with Array[String] does not work if it's the only one. It immediately works when you add a non array/string param:

params do
  requires :tags, type: Array[String], documentation: { in: 'body' }
  requires :lol, documentation: { in: 'body' }
end

Results in:

{
  "name": "V1PostMortemsReportsReportIdTags",
  "in": "body",
  "required": true,
  "schema": {
    "$ref": "#/definitions/putV1PostMortemsReportsReportIdTags"
  }
}

And the schema:

{
  "type": "object",
  "properties": {
    "tags": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "lol": {
      "type": "string"
    }
  },
  "required": [
    "tags",
    "lol"
  ],
  "description": "Add tags to a report"
}

What's also peculiar is that if you add multiple Array[String] to params it maintains the same bug, I've only been able to get to work the moment you add a non-array param.

[dblock]

This is similar or at least related to #721.

[bobbytables]

We hit this again today, where is a good place to look in the code base and provide a fix @dblock ?

[dblock]

I am not sure, @LeFnord might know more.

[LeFnord]

will have a look on it …

[tristil]

More info about this here: #721 (comment)

[oslivan]

I find a PR about my problem, but I don't understand why it is.

[LeFnord]

created a sample project to check it out … see how_to_array_params it works as expected

[oslivan]

@LeFnord I used your sample project, and put some pictures about swagger_ui render, you can see the actual effect.
Picture 1
Pitcture 2
It'd submit a array, not like below

{
  names: ["aaa", "bbb"]
}

[LeFnord]

ah, now I see the point …

it will be documented correct as array

"parameters": [
  {
    "in": "body",
    "name": "names",
    "required": true,
    "schema": {
      "type": "array",
      "items": {
        "type": "string"
      }
    }
  }
],

but grape accept it only with given name … this way

{
  "names": [
    "a", "b"
  ]
}

🤔

[LeFnord]

ok, checked it … the documentation above is correct and it must be used for body as above, for x-www-form-urlencoded it must be done a similar way via &names[]=a&names[]=b, so it seems the behaviour is correct

[oslivan]

ok, checked it … the documentation above is correct and it must be used for body as above, for x-www-form-urlencoded it must be done a similar way via &names[]=a&names[]=b, so it seems the behaviour is correct

You mean that the documentation is correct, and the grape needs to support this form?

[thanhnha1103]

I'm facing the same issue with version 1.3.1

optional :booking_ids, type: Array, desc: 'Booking ID of Location'

Generate

curl -X GET ...... -d 'booking_ids=123&booking_ids=456' 'domain/api/v1/locations'

And

optional :booking_ids, type: Array, desc: 'Booking ID of Location', documentation: { param_type: 'body' }

Generate

curl -X GET ...... -d '["81852"]' 'domain/api/v1/locations'

I guest both above are not correct, it should be something like below: (with the [])

curl -X GET ...... -d 'booking_ids[]=123&booking_ids[]=456' 'domain/api/v1/locations'

[urkle]

The issue is with the hack added in #553 that screws up the parameter doc generation.
so it generates swagger docs expecting params of an un-named array. [1,2,3]
If I disable that code, then the docs are still generated incorrectly, as they are generated as an array of objects with an array.

e.g. swagger is expecting this [{booking_ids: [1,2,3]}]
vs. what we all want to happen
{booking_ids: [1,2,3]}