MIME type with period causes validation to fail

[gward]

Here is a very simple swagger spec, which I created with the Swagger Editor:

$ cat /tmp/swagger.json 
{
    "swagger": "2.0",
    "info": {
        "title": "example",
        "version": "1.0.0"
    },
    "schemes": [
        "https"
    ],
    "produces": [
        "application/vnd.example+json"
    ],
    "paths": {
        "/products": {
            "get": {
                "summary": "stuff",
                "description": "stuff",
                "responses": {
                    "200": {
                        "description": "array of strings",
                        "schema": {
                            "type": "array",
                            "items": {
                                "type": "string"
                            }
                        },
                        "examples": {
                            "application/vnd.example+json": [
                                "foo",
                                "bar"
                            ]
                        }
                    }
                }
            }
        }
    }
}

If I use swagger_spec_validator on this, it fails:

$ python -c 'import swagger_spec_validator as v; v.validate_spec_url("file:///tmp/swagger.json")'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/var/lib/venv/tapi/local/lib/python2.7/site-packages/swagger_spec_validator/common.py", line 22, in wrapper
    sys.exc_info()[2])
  File "/var/lib/venv/tapi/local/lib/python2.7/site-packages/swagger_spec_validator/common.py", line 17, in wrapper
    return method(*args, **kwargs)
  File "/var/lib/venv/tapi/local/lib/python2.7/site-packages/swagger_spec_validator/util.py", line 53, in validate_spec_url
    validator.validate_spec(spec_json, spec_url)
  File "/var/lib/venv/tapi/local/lib/python2.7/site-packages/swagger_spec_validator/validator20.py", line 82, in validate_spec
    http_handlers=http_handlers)
  File "/var/lib/venv/tapi/local/lib/python2.7/site-packages/swagger_spec_validator/common.py", line 22, in wrapper
    sys.exc_info()[2])
  File "/var/lib/venv/tapi/local/lib/python2.7/site-packages/swagger_spec_validator/common.py", line 17, in wrapper
    return method(*args, **kwargs)
  File "/var/lib/venv/tapi/local/lib/python2.7/site-packages/swagger_spec_validator/validator20.py", line 125, in validate_json
    cls=Draft4Validator)
  File "/var/lib/venv/tapi/local/lib/python2.7/site-packages/swagger_spec_validator/ref_validators.py", line 34, in validate
    instance_cls(schema, *args, **kwargs).validate(instance)
  File "/var/lib/venv/tapi/local/lib/python2.7/site-packages/jsonschema/validators.py", line 123, in validate
    raise error
swagger_spec_validator.common.SwaggerValidationError: {u'examples': {u'application/vnd.example+json': [u'foo', u'bar']}, u'description': u'array of strings', u'schema': {u'items': {u'type': u'string'}, u'type': u'array'}} is not valid under any of the given schemas

Failed validating 'oneOf' in schema['properties']['paths']['patternProperties']['^/']['properties']['get']['properties']['responses']['patternProperties']['^([0-9]{3})$|^(default)$']:
    {'oneOf': [{'$ref': '#/definitions/response'},
               {'$ref': '#/definitions/jsonReference'}]}

On instance['paths'][u'/products']['get']['responses'][u'200']:
    {u'description': u'array of strings',
     u'examples': {u'application/vnd.example+json': [u'foo', u'bar']},
     u'schema': {u'items': {u'type': u'string'}, u'type': u'array'}}

It appears that the reason for the failure is the period in the MIME type used in the examples object. If I remove the period:

--- swagger.json.orig	2017-02-02 11:55:49.539545943 -0500
+++ swagger.json	2017-02-02 11:55:53.799656809 -0500
@@ -25,7 +25,7 @@
                             }
                         },
                         "examples": {
-                            "application/vnd.example+json": [
+                            "application/vndexample+json": [
                                 "foo",
                                 "bar"
                             ]

then validation passes:

$ python -c 'import swagger_spec_validator as v; v.validate_spec_url("file:///tmp/swagger.json")'

[gward]

I'm following https://tools.ietf.org/html/rfc6838#section-4.2 for naming of vendor media types here.