Data is not automatically validated when using flask-restful & json template_file

[caffeinatedMike]

TLDR; Expected Behavior:
Since we use a universal/app-wide schema, as defined by the template_file parameter when instantiating Swagger, we should not have to add validation decorators to all flask-restful Resources & their respective methods.

---

I'm currently designing an API and have run into a situation where when I define my entire schema from a json template file and am utilizing flask-restful Resource classes the data provided in the API calls is not validated.

Posting to /product with a valid payload results in the expected 501 response. But, posting with an invalid payload also results in a 501 response.

Expected Payload:

{
  "id": 0,
  "name": "Toy",
  "photoUrls": [
    "string"
  ],
  "status": "available"
}

Payload that should fail validation:

{
  "id": 0,
  "name": "test",
  "status": "available"
}

Below is a snippet of the Resource class and how I have flasgger configured

# https://github.com/flasgger/flasgger
# pip install flask flasgger flask-restful
from flasgger import Swagger, LazyString, LazyJSONEncoder
from flask import Flask, jsonify, request, url_for
from flask_restful import Api, Resource

app = Flask(__name__)
api = Api(app)

app.json_encoder = LazyJSONEncoder
app.config['SWAGGER'] = {
    'title': 'TestAPI',
    'uiversion': 3,
    'favicon': LazyString(lambda: url_for('static', filename='logo.png')),
    'swagger_ui_css': LazyString(lambda: url_for('static', filename='swagger-ui.css')),
    'specs_route': '/docs/'
}

swagger = Swagger(app, template_file='static/Swagger.json')

class NewProduct(Resource):
    def post(self):
        return '', 501

api.add_resource(NewProduct, '/product')

if __name__ == "__main__":
    app.run(debug=True)

And below is the contents of the Swagger.json file

{
  "swagger": "2.0",
  "info": {
    "description": "",
    "version": "1.0.0",
    "title": "POC for Non-validation Issue",
    "termsOfService": "http://swagger.io/terms/",
    "contact": {
      "email": "testing@abc.com"
    },
    "license": {
      "name": "Apache 2.0",
      "url": "http://www.apache.org/licenses/LICENSE-2.0.html"
    }
  },
  "host": "",
  "basePath": "/",
  "tags": [
    {
      "name": "Product",
      "description": "Operations to manage product info",
      "externalDocs": {
        "description": "Find out more",
        "url": "http://swagger.io"
      }
    }
  ],
  "schemes": [
    "http"
  ],
  "paths": {
    "/product": {
      "post": {
        "tags": [
          "Product"
        ],
        "summary": "Add a new product",
        "description": "",
        "operationId": "addProduct",
        "consumes": [
          "application/json"
        ],
        "produces": [
          "application/json"
        ],
        "parameters": [
          {
            "in": "body",
            "name": "body",
            "description": "",
            "required": true,
            "schema": {
              "$ref": "#/definitions/Product"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "Product created"
          },
          "405": {
            "description": "Invalid input"
          },
          "501": {
            "description": "Not Yet Implemented"
          }
        }
      }
    }
  },
  "definitions": {
    "Product": {
      "type": "object",
      "required": [
        "name",
        "photoUrls"
      ],
      "properties": {
        "id": {
          "type": "integer",
          "format": "int64"
        },
        "name": {
          "type": "string",
          "example": "Toy"
        },
        "photoUrls": {
          "type": "array",
          "xml": {
            "name": "photoUrl",
            "wrapped": true
          },
          "items": {
            "type": "string"
          }
        },
        "status": {
          "type": "string",
          "description": "State of availability",
          "enum": [
            "available",
            "pending",
            "sold"
          ]
        }
      },
      "xml": {
        "name": "Toy"
      }
    }
  }
}

[caffeinatedMike]

The original issue is resolved by adding parse=True when instantiating Swagger. While this parameter is covered in the README, I think it would benefit from being elaborated upon a bit more and maybe showing an example that utilizes the functionality.

Now the only issue I'm facing is directly related to #330. Once that is merged my setup works fine.