python-amazon-mws · jameshiew · Nov 14, 2017 · Aug 12, 2017 · Aug 12, 2017 · Aug 12, 2017
diff --git a/mws/mws.py b/mws/mws.py
@@ -70,6 +70,14 @@ def calc_md5(string):
     return base64.b64encode(md.digest()).strip(b'\n')
 
 
+def calc_request_description(params):
+    request_description = ''
+    for key in sorted(params):
+        encoded_value = quote(params[key], safe='-_.~')
+        request_description += '&{}={}'.format(key, encoded_value)
+    return request_description[1:]  # don't include leading ampersand
+
+
 def remove_empty(d):
     """Helper function that removes all keys from a dictionary (d), that have an empty value.
 
@@ -165,6 +173,20 @@ def __init__(self, access_key, secret_key, account_id, region='US', domain='', u
             }
             raise MWSError(error_msg)
 
+    def get_params(self):
+        """Get the parameters required in all MWS requests"""
+        params = {
+            'AWSAccessKeyId': self.access_key,
+            self.ACCOUNT_TYPE: self.account_id,
+            'SignatureVersion': '2',
+            'Timestamp': self.get_timestamp(),
+            'Version': self.version,
+            'SignatureMethod': 'HmacSHA256',
+        }
+        if self.auth_token:
+            params['MWSAuthToken'] = self.auth_token
+        return params
+
     def make_request(self, extra_data, method="GET", **kwargs):
         """Make request to Amazon MWS API with these parameters
         """
@@ -178,18 +200,9 @@ def make_request(self, extra_data, method="GET", **kwargs):
             if isinstance(value, (datetime.datetime, datetime.date)):
                 extra_data[key] = value.isoformat()
 
-        params = {
-            'AWSAccessKeyId': self.access_key,
-            self.ACCOUNT_TYPE: self.account_id,
-            'SignatureVersion': '2',
-            'Timestamp': self.get_timestamp(),
-            'Version': self.version,
-            'SignatureMethod': 'HmacSHA256',
-        }
-        if self.auth_token:
-            params['MWSAuthToken'] = self.auth_token
+        params = self.get_params()
         params.update(extra_data)
-        request_description = '&'.join(['%s=%s' % (k, quote(params[k], safe='-_.~')) for k in sorted(params)])
+        request_description = calc_request_description(params)
         signature = self.calc_signature(method, request_description)
         url = '%s%s?%s&Signature=%s' % (self.domain, self.uri, request_description, quote(signature))
         headers = {'User-Agent': 'python-amazon-mws/0.0.1 (Language=Python)'}

diff --git a/tests/conftest.py b/tests/conftest.py
@@ -0,0 +1,31 @@
+import pytest
+
+
+@pytest.fixture
+def access_key():
+    return "AAAAAAAAAAAAAAAAAAAA"
+
+
+@pytest.fixture
+def secret_key():
+    return "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
+
+
+@pytest.fixture
+def account_id():
+    return "AAAAAAAAAAAAAA"
+
+
+@pytest.fixture
+def timestamp():
+    return '2017-08-12T19:40:35Z'
+
+
+@pytest.fixture
+def credentials(access_key, secret_key, account_id):
+    """Fake set of MWS credentials"""
+    return {
+        "access_key": access_key,
+        "secret_key": secret_key,
+        "account_id": account_id,
+    }
diff --git a/tests/test_service_status.py b/tests/test_service_status.py
@@ -1,9 +1,9 @@
 import mws
 
 
-def test_get_service_status():
+def test_get_service_status(credentials):
     # we can get the service status without needing API credentials
     # this is a simple smoke test to check that the simplest API request can be successfully made
-    orders_api = mws.Orders(access_key='', secret_key='', account_id='')
+    orders_api = mws.Orders(**credentials)
     r = orders_api.get_service_status()
     assert r.response.status_code == 200
diff --git a/tests/test_utils.py b/tests/test_utils.py
@@ -1,5 +1,24 @@
-from mws.mws import calc_md5
+from mws.mws import calc_md5, calc_request_description
 
 
 def test_calc_md5():
     assert calc_md5(b'mws') == b'mA5nPbh1CSx9M3dbkr3Cyg=='
+
+
+def test_calc_request_description(access_key, account_id):
+    request_description = calc_request_description({
+        'AWSAccessKeyId': access_key,
+        'Markets': account_id,
+        'SignatureVersion': '2',
+        'Timestamp': '2017-08-12T19:40:35Z',
+        'Version': '2017-01-01',
+        'SignatureMethod': 'HmacSHA256',
+    })
+    assert not request_description.startswith('&')
+    assert request_description == \
+        'AWSAccessKeyId=' + access_key + \
+        '&Markets=' + account_id + \
+        '&SignatureMethod=HmacSHA256' \
+        '&SignatureVersion=2' \
+        '&Timestamp=2017-08-12T19%3A40%3A35Z' \
+        '&Version=2017-01-01'