Uppercase letters in user's email address causes webhook to fail on subscription creation

[agmathew]

• dj-paddle version: 0.1.2
• Django version: 4.2.3
• Python version: 3.9.9
• Operating System: Linux

Description

In production, we had an error when a user created a subscription and a webhook was sent:

"Subscriber could not be found for subscription <subscription_id> with payload".

We narrowed down the problem to a case sensitivity issue. Specifically if a user registered on our site with an uppercase letter and then tried to subscribe, the Paddle JS front end would lowercase the email address by default. When the subscription_created webhook was fired, the mapping would fail to find the associated user and they wouldn't be successfully marked as having a paid subscription. Unfortunately this affected our very first paying customer - talk about bad luck!

What I Did

• Create a user like 'Test@example.com' with an uppercase letter in their email address.
• Try to initiate a subscription using the Paddle UI
• Note that the UI will default to lowercasing their email address (you can also probably just manually change the casing in the Paddle modal).
• Complete the payment
• You get an error when the subscription_created webhook is fired stating that the user is not found.

Workaround

You can override the default mapping by setting the settings param DJPADDLE_SUBSCRIBER_BY_PAYLOAD. Then you can replace the default djpaddle.mappers.subscriber_by_payload() and make sure you're doing a case-insensitive search.

Fix

I believe the user search should be case-insensitive, since subscriptions_by_subscriber() is also doing a case-insensitive search. I'll try to submit a pull request.