MediaType Validation does not support case insensitive Charset

[tobiasvoelke]

Describe the bug
According to RFC2046 the charset in media types should be case insensitive. Whenever I pass a content-type where the charset does not match the case of the api spec I receive unsupported media type <...>. In case of a uppercase charset in the api spec even setting only the media type will fail

To Reproduce

1. Provide API Spec containing a content-type with charset like e.g. 'application/json; charset=UTF-8'
   Send a request with content-type 'application/json; charset=utf-8' or 'application/json'

2. Provide API Spec containing a content-type with charset like e.g. 'application/json; charset=utf-8'
   Send a request with content-type 'application/json; charset=UTF-8'

Actual behavior
Media Type validation fails with unsupported media type <...>

Expected behavior
Should accept charsets that only differ in casing

Examples and context

const express = require('express');
const bodyParser = require('body-parser')

const app = express();
const OpenApiValidator = require('express-openapi-validator');

app.use(bodyParser.json());

app.use(
  OpenApiValidator.middleware({
    apiSpec: 'api.yaml',
    validateResponses: true,
  }),
);

app.post('/api/foo', function (req, res, next) {
  res.json({});
});

app.listen(8080)

openapi: '3.0.3'
info:
  title: Dummy
  version: '0.1.0'

paths:
  /api/foo:
    post:
      requestBody:
        content:
          'application/json; charset=utf-8':
            schema:
              type: object
      responses:
        200:
          description: OK
          content:
            'application/json; charset=utf-8':
              schema:
                type: object

POST http://localhost:8080/api/foo
Content-Type: application/json; charset=UTF-8

{"foo":  "test"}

Providing the content-type as 'application/json; charset=UTF-8' in the spec will also cause API calls with content-type: application/json to fail.

openapi: '3.0.3'
info:
  title: Dummy
  version: '0.1.0'

paths:
  /api/foo:
    post:
      requestBody:
        content:
          'application/json; charset=UTF-8':
            schema:
              type: object
      responses:
        200:
          description: OK
          content:
            'application/json; charset=UTF-8':
              schema:
                type: object

POST http://localhost:8080/api/foo
Content-Type: application/json

{"foo":  "test"}

[cdimascio]

@tobiasvoelke thanks for the issue. definitely something we'll want to fix.

[cdimascio]

fixed in v4.10.1

[jayakrishnar]

The issue back again in version 4.13.7