idempotency for stripe transfer, refund, charge

backend/services/stripeService.js

@@ -104,12 +104,20 @@ class StripeService {
     metadata = {},
   }) {
     try {
-      const transfer = await stripe.transfers.create({
-        amount: Math.round(amount * 100), // Convert to cents
-        currency,
-        destination,
-        metadata,
-      });
+      // Generate idempotency key from rental ID to prevent duplicate transfers
+      const idempotencyKey = metadata?.rentalId
+        ? `transfer_rental_${metadata.rentalId}`
+        : undefined;
+
+      const transfer = await stripe.transfers.create(
+        {
+          amount: Math.round(amount * 100), // Convert to cents
+          currency,
+          destination,
+          metadata,
+        },
+        idempotencyKey ? { idempotencyKey } : undefined
+      );
 
       return transfer;
     } catch (error) {
@@ -216,12 +224,20 @@ class StripeService {
     reason = "requested_by_customer",
   }) {
     try {
-      const refund = await stripe.refunds.create({
-        payment_intent: paymentIntentId,
-        amount: Math.round(amount * 100), // Convert to cents
-        metadata,
-        reason,
-      });
+      // Generate idempotency key - include amount to allow multiple partial refunds
+      const idempotencyKey = metadata?.rentalId
+        ? `refund_rental_${metadata.rentalId}_${Math.round(amount * 100)}`
+        : undefined;
+
+      const refund = await stripe.refunds.create(
+        {
+          payment_intent: paymentIntentId,
+          amount: Math.round(amount * 100), // Convert to cents
+          metadata,
+          reason,
+        },
+        idempotencyKey ? { idempotencyKey } : undefined
+      );
 
       return refund;
     } catch (error) {
@@ -252,20 +268,28 @@ class StripeService {
     metadata = {}
   ) {
     try {
+      // Generate idempotency key to prevent duplicate charges for same rental
+      const idempotencyKey = metadata?.rentalId
+        ? `charge_rental_${metadata.rentalId}`
+        : undefined;
+
       // Create a payment intent with the stored payment method
-      const paymentIntent = await stripe.paymentIntents.create({
-        amount: Math.round(amount * 100), // Convert to cents
-        currency: "usd",
-        payment_method: paymentMethodId,
-        customer: customerId, // Include customer ID
-        confirm: true, // Automatically confirm the payment
-        off_session: true, // Indicate this is an off-session payment
-        return_url: `${
-          process.env.FRONTEND_URL || "http://localhost:3000"
-        }/complete-payment`,
-        metadata,
-        expand: ["latest_charge.payment_method_details"], // Expand to get payment method details
-      });
+      const paymentIntent = await stripe.paymentIntents.create(
+        {
+          amount: Math.round(amount * 100), // Convert to cents
+          currency: "usd",
+          payment_method: paymentMethodId,
+          customer: customerId, // Include customer ID
+          confirm: true, // Automatically confirm the payment
+          off_session: true, // Indicate this is an off-session payment
+          return_url: `${
+            process.env.FRONTEND_URL || "http://localhost:3000"
+          }/complete-payment`,
+          metadata,
+          expand: ["latest_charge.payment_method_details"], // Expand to get payment method details
+        },
+        idempotencyKey ? { idempotencyKey } : undefined
+      );
 
       // Check if additional authentication is required
       if (paymentIntent.status === "requires_action") {