Writing unit tests for stripe webhooks stripe-signature

Question

I'm trying to write unit tests for Stripe webhooks. The problem is I'm also verifying the stripe-signature and it fails as expected.

Is there a way to pass a correct signature in tests to the webhook with mock data?

This is the beginning of the webhook route I'm trying to handle

// Retrieve the event by verifying the signature using the raw body and secret.
let event: Stripe.Event;
const signature = headers["stripe-signature"];

try {
  event = stripe.webhooks.constructEvent(
    raw,
    signature,
    context.env.stripeWebhookSecret
  );
} catch (err) {
  throw new ResourceError(RouteErrorCode.STRIPE_WEBHOOK_SIGNATURE_VERIFICATION_FAILD);
}

// Handle event...

And the current test I'm trying to handle, I'm using Jest:

const postData = { MOCK WEBHOOK EVENT DATA }

const result = await request(app.app)
  .post("/webhook/stripe")
  .set('stripe-signature', 'HOW TO GET THIS SIGNATURE?')
  .send(postData);

Answer 1

Stripe now exposes a function in its node library that they recommend for creating signatures for testing:

Testing Webhook signing

You can use stripe.webhooks.generateTestHeaderString to mock webhook events that come from Stripe:

const payload = {
  id: 'evt_test_webhook',
  object: 'event',
};

const payloadString = JSON.stringify(payload, null, 2);
const secret = 'whsec_test_secret';

const header = stripe.webhooks.generateTestHeaderString({
  payload: payloadString,
  secret,
});

const event = stripe.webhooks.constructEvent(payloadString, header, secret);

// Do something with mocked signed event
expect(event.id).to.equal(payload.id);

ref: https://github.com/stripe/stripe-node#webhook-signing