Add response code documentation

app/MRE/api.py

@@ -25,15 +25,22 @@ MRE_request_parser.add_argument('down_payment',
 
 @namespace.route('/compute_mre')
 @namespace.doc(params={
-    'consumer_fico': 'The consumer\'s fico score (int).',
-    'home_price': 'The price of the home (float).',
-    'down_payment': 'The down_payment percentage (float).'
+    'consumer_fico': 'The consumer\'s fico score (int) range: [620, 850].',
+    'home_price': 'The price of the home (float) range: [0, inf).',
+    'down_payment': 'The down_payment percentage (float) range: [0-1].'
 })
 class ComputeMRE(Resource):
-    @namespace.doc(description='Computes and returns the MRE.')
+    @namespace.expect(MRE_request_parser)
+    @namespace.doc(description='Computes and returns the MRE.',
+                   responses={
+                   200: 'Good',
+                   400: 'Validation Error'
+                   })
     def get(self):
         args = MRE_request_parser.parse_args()
-        mre = compute_mre(args.home_price, args.down_payment, args.consumer_fico)
-
-        return {'consumer_mre': mre}
+        try:
+            mre = compute_mre(args.home_price, args.down_payment, args.consumer_fico)
+            return {'consumer_mre': mre}
+        except ValueError as ve:
+            return {'error': str(ve)}, 400