billing: Expand default_source object when retrieving customer.

zilencer/lib/stripe.py

@@ -91,7 +91,7 @@ def catch_stripe_errors(func: CallableT) -> CallableT:
 
 @catch_stripe_errors
 def get_stripe_customer(stripe_customer_id: str) -> stripe.Customer:
-    stripe_customer = stripe.Customer.retrieve(stripe_customer_id)
+    stripe_customer = stripe.Customer.retrieve(stripe_customer_id, expand=["default_source"])
     if PRINT_STRIPE_FIXTURE_DATA:
         print(''.join(['"retrieve_customer": ', str(stripe_customer), ',']))  # nocoverage
     return stripe_customer
@@ -113,15 +113,6 @@ def extract_current_subscription(stripe_customer: stripe.Customer) -> Any:
             return stripe_subscription
     return None
 
-@catch_stripe_errors
-def payment_source(stripe_customer: stripe.Customer) -> Optional[stripe.Card]:
-    if stripe_customer.default_source is None:
-        return None  # nocoverage -- no way to get here yet
-    for source in stripe_customer.sources.data:
-        if source.id == stripe_customer.default_source:
-            return source
-    raise AssertionError("Default source not in sources.")
-
 @catch_stripe_errors
 def do_create_customer_with_payment_source(user: UserProfile, stripe_token: str) -> stripe.Customer:
     realm = user.realm

zilencer/tests/stripe_fixtures.json

@@ -138,7 +138,31 @@
         "account_balance": 0,
         "created": 1529990750,
         "currency": "usd",
-        "default_source": "card_1Ch9gVGh0CmXqmnwv94RombT",
+        "default_source": {
+            "address_city": "Pacific",
+            "address_country": "United States",
+            "address_line1": "Under the sea",
+            "address_line1_check": "pass",
+            "address_line2": null,
+            "address_state": "FL",
+            "address_zip": "33333",
+            "address_zip_check": "pass",
+            "brand": "Visa",
+            "country": "US",
+            "customer": "cus_D7OT2jf5YAtZQL",
+            "cvc_check": "pass",
+            "dynamic_last4": null,
+            "exp_month": 3,
+            "exp_year": 2033,
+            "fingerprint": "6dAXT9VZvwro65EK",
+            "funding": "credit",
+            "id": "card_1Ch9gVGh0CmXqmnwv94RombT",
+            "last4": "4242",
+            "metadata": {},
+            "name": "Ada Starr",
+            "object": "card",
+            "tokenization_method": null
+        },
         "delinquent": false,
         "description": "zulip (Zulip Dev)",
         "discount": null,

zilencer/views.py

@@ -27,8 +27,8 @@ from zerver.models import UserProfile, Realm
 from zerver.views.push_notifications import validate_token
 from zilencer.lib.stripe import STRIPE_PUBLISHABLE_KEY, StripeError, \
     do_create_customer_with_payment_source, do_subscribe_customer_to_plan, \
-    get_stripe_customer, get_upcoming_invoice, payment_source, \
+    get_stripe_customer, get_upcoming_invoice, get_seat_count, \
-    get_seat_count, extract_current_subscription, sign_string, unsign_string
+    extract_current_subscription, sign_string, unsign_string
 from zilencer.models import RemotePushDeviceToken, RemoteZulipServer, \
     Customer, Plan
 
@@ -249,9 +249,8 @@ def billing_home(request: HttpRequest) -> HttpResponse:
         prorated_charges = 0
 
     payment_method = None
-    source = payment_source(stripe_customer)
+    if stripe_customer.default_source is not None:
-    if source is not None:
+        payment_method = "Card ending in %(last4)s" % {'last4': stripe_customer.default_source.last4}
-        payment_method = "Card ending in %(last4)s" % {'last4': source.last4}
 
     context.update({
         'plan_name': plan_name,