Add success or failure to vend endpoint

Author: abrandemuehl

machine_controller/app.py

@@ -47,15 +47,23 @@ def hello_world():
         abort(401)
     data = request.json()
     items = data['items']
+    transaction_id = data['transaction_id']
 
+
+    statuses = []
     for i, item in enumerate(items):
         try:
             merch.vend(item[0], int(item[1]))
-        except:
-            # Some error occurred, return the first index that failed
-            return jsonify(success=False, failed=i)
+            statuses.append({'error': None, 'location': item})
+
+        except Exception as e:
+            # Some error occurred while vending
+            # I'd prefer to catch Merch.VendError's only, but if something else
+            # goes wrong, we still need to let the client know instead of
+            # throwing a 500
+            statuses.append({'error': str(e), 'location': item})
 
-    return jsonify(success=True)
+    return jsonify(transaction_id=transaction_id, items=statuses)
 
 if __name__ == '__main__':
     # Make sure flask runs in a single thread. Otherwise concurrent requests

machine_controller/vend.py

@@ -44,6 +44,11 @@ class Merch:
     MAX_LETTER = 'F'
     MAX_NUMBER = '0'
 
+    class VendError(Exception):
+        pass
+
+    InvalidLocationError = VendError("Invalid location")
+
     def __init__(self, debug=False):
         self.debug = debug
 
@@ -93,22 +98,24 @@ def vend(self, letter, number):
         try:
             char = ord(letter)
         except TypeError:
-            raise TypeError('Letter %s does not represent a character' %
-                            str(letter))
+            raise Merch.VendError("Invalid location: %s" %
+                                  (str(letter) + str(number)))
 
         # Maybe we should use the actual keypad value?
         if char < ord('A') or char > ord('Z'):
-            raise ValueError('Invalid Letter: %s' % str(letter))
+            raise Merch.VendError("Invalid location: %s" %
+                                  (str(letter) + str(number)))
 
         num = 0
         try:
             num = int(number)
         except TypeError:
-            raise TypeError('Number %s is not convertible to an integer' %
-                            str(num))
+            raise Merch.VendError("Invalid location: %s" %
+                                  (str(letter) + str(number)))
 
         if num < 0 or num > 10:
-            raise ValueError('Number %d is not in the range 1-10' % num)
+            raise Merch.VendError("Invalid location: %s" %
+                                  (str(letter) + str(number)))
 
         self.__vend(letter, str(number))