Pattern validation not applied to individual values in case of comma separated query params

[KPranith]

Steps to recreate the issue

1. Change query.json /pets petId parameter like below
   {
   "name": "petId",
   "in": "query",
   "required": true,
   "description": "The id of the pet to retrieve",
   "schema": {
   "type": "array",
   "items": {
   "type": "string",
   "pattern": "^[A-Z0-9]+-[0-9]{4}"
   }
   }
   }
2. change the test case should coerce query parameter to an array in query.spec.ts as below

it('should coerce query parameter to an array', () => {
const queryMeta = {
method: 'get',
query: {
petId:'ACD-2016,ACD-213'
}
};
expect(chowchow.validateRequest('/pets', queryMeta)).toEqual(expect.objectContaining({
query: {
petId: ['ACD-2016,ACD-213']
}
}));
expect(queryMeta.query.petId).toEqual('ACD-2016,ACD-213');
});

As the string ACD-213 is not matching the pattern it should fail but it doesn't

[KPranith]

@TageNielsen FYI..

[supertong]

Hey @KPranith , the example you provided is taking the whole 'ACD-2016,ACD-213' as a single array item which matches the regex pattern you provided - "pattern": "^[A-Z0-9]+-[0-9]{4}".
At the moment, this library is expecting the query string to be parsed before pass in for validation. If you pass in 'ACD-2016,ACD-213', it will be taken as a string instead of doing further parsing to an array.

[KPranith]

Thank You @supertong ,

You meant the query string has to be parsed
from 'ACD-2016,ACD-213'
to ['ACD-2016','ACD-213']
and then sent to the library

Are there any other such parsing (pre processing) that has to be done before its passed in for validation ?

Would submitting a PR to parse comma separated values to an array would help as a feature for other users ?

[supertong]

Hey @KPranith , we have library like https://github.com/atlassian/koa-oas3 that using this library under the hood and it's also using the https://github.com/sindresorhus/query-string for parsing that.
Depends on the style and explode you specified in the Parameter Object, there could be more combination than the comma separated one. https://swagger.io/specification . I have a thinking of parsing the query depends on the style and explode specified in the document, but haven't got time to implement it yet.