Swagger Validator complaining about seemingly well-formed request - rest

Question

I'm using the swagger-express-validator to validate inputs to a small API server (using Swagger 2 format)
My path definition is as follows
/api/v1/users:
post:
produces:
- "application/json"
parameters:
- in: body
name: ids
description: Array of user ids to be processed
required: true
schema:
$ref: "#/definitions/ArrayOfIds"
responses:
200:
description: success
ArrayOfIds is defined as follows
Id:
type: string
ArrayOfIds:
type: array
items:
$ref: "#/definitions/Id"
Sending a post request to the server as follows:
POST /api/v1/users HTTP/1.1
Content-Type: application/json
Accept: application/json
Host: localhost:3000
Connection: close
User-Agent: Paw/3.1.7 (Macintosh; OS X/10.13.6) GCDHTTPRequest
Content-Length: 35
{
"ids": ["abcd12345"]
}
Results in an error
Request Invalid: POST /api/v1/users
[ { keyword: 'type',
dataPath: '',
schemaPath: '#/type',
params: { type: 'array' },
message: 'should be array' } ]
I am however able to access req.body.ids in my Express route controller code and it contains the correct value ['1234abc'].
Do you have any idea as to why the validator is complaining about the request? It looks fine to me.

Answer 1

Your request body does not match the definition. According to the definition, the array in the request body must be unwrapped:
POST /api/v1/users HTTP/1.1
Content-Type: application/json
...
["abcd12345"]
If the array needs to be wrapped into the ids wrapper property, the request body should be defined as type: object with the property ids that contains the array:
parameters:
- in: body
name: ids
description: Array of user ids to be processed
required: true
schema:
type: object
properties:
ids:
$ref: "#/definitions/ArrayOfIds"