Correctly honor the restrictions on start_date

tap_appsflyer/__init__.py

@@ -39,12 +39,20 @@ def af_datetime_str_to_datetime(s):
     return datetime.datetime.strptime(s.strip(), "%Y-%m-%d %H:%M:%S")
 
 
+def get_restricted_start_date(date: str) -> datetime.datetime:
+    # https://support.appsflyer.com/hc/en-us/articles/207034366-API-Policy
+    restriction_date = datetime.datetime.now() - datetime.timedelta(days=90)
+    start_date = utils.strptime(date)
+
+    return max(start_date, restriction_date)
+
+
 def get_start(key):
     if key in STATE:
-        return  utils.strptime(STATE[key])
+        return  get_restricted_start_date(STATE[key])
 
     if "start_date" in CONFIG:
-        return  utils.strptime(CONFIG["start_date"])
+        return  get_restricted_start_date(CONFIG["start_date"])
 
     return datetime.datetime.now() - datetime.timedelta(days=30)
 

tests/unittests/test_helpers.py

@@ -0,0 +1,24 @@
+import datetime
+from unittest.mock import patch
+
+from tap_appsflyer import get_restricted_start_date
+
+MOCKED_DATE = datetime.datetime(2021, 7, 1, 1, 1, 1, 369251)
+
+class MockedDatetime(datetime.datetime):
+    def now():
+        return MOCKED_DATE
+
+@patch('datetime.datetime', MockedDatetime)
+def test_get_restricted_start_date():
+    test_cases = [
+        {'case': '2018-01-01T00:00:00Z', 'expected': datetime.datetime(2021, 4, 2, 1, 1, 1, 369251)},
+        {'case': '2021-07-27T00:00:00Z', 'expected': datetime.datetime(2021, 7, 27, 0, 0)},
+        {'case': '2021-04-02T00:00:00Z', 'expected': datetime.datetime(2021, 4, 2, 1, 1, 1, 369251)},
+        {'case': '2021-05-23T12:34:56Z', 'expected': datetime.datetime(2021, 5, 23, 12, 34, 56)},
+    ]
+
+    for test_case in test_cases:
+        date = get_restricted_start_date(test_case['case'])
+
+        assert date == test_case['expected']