feat: Refund payment (#6610)

Essentially the same as #6601 but for refunds

packages/payment/src/migrations/Migration20240225134525.ts

@@ -6,7 +6,7 @@ export class Migration20240225134525 extends Migration {
     const paymentCollectionExists = await this.execute(
       `SELECT * FROM information_schema.tables where table_name = 'payment_collection' and table_schema = 'public';`
     )
-    
+
     if (paymentCollectionExists.length) {
       this.addSql(`
         ${generatePostgresAlterColummnIfExistStatement(
@@ -39,6 +39,12 @@ export class Migration20240225134525 extends Migration {
 
         ALTER TABLE IF EXISTS "refund" ADD COLUMN IF NOT EXISTS "raw_amount" JSONB NOT NULL;
         ALTER TABLE IF EXISTS "refund" ADD COLUMN IF NOT EXISTS "deleted_at" TIMESTAMPTZ NULL;
+        ALTER TABLE IF EXISTS "refund" ADD COLUMN IF NOT EXISTS "created_by" TEXT NULL;
+        ${generatePostgresAlterColummnIfExistStatement(
+          "refund",
+          ["reason"],
+          "DROP NOT NULL"
+        )}
 
         CREATE TABLE IF NOT EXISTS "capture" (
           "id"          TEXT NOT NULL,

packages/payment/src/services/payment-module.ts

@@ -450,9 +450,9 @@ export default class PaymentModuleService<
       )
     }
 
-    const capturedAmount = payment.captures.reduce((acc, next) => {
-      const bn = new BigNumber(next.raw_amount.value)
-      return acc.plus(bn)
+    const capturedAmount = payment.captures.reduce((captureAmount, next) => {
+      const amountAsBigNumber = new BigNumber(next.raw_amount.value)
+      return captureAmount.plus(amountAsBigNumber)
     }, BigNumber(0))
 
     const authorizedAmount = BigNumber(payment.raw_amount.value)
@@ -507,17 +507,29 @@ export default class PaymentModuleService<
   ): Promise<PaymentDTO> {
     const payment = await this.paymentService_.retrieve(
       data.payment_id,
-      { select: ["id", "data", "provider_id"] },
+      {
+        select: ["id", "data", "provider_id", "amount", "raw_amount"],
+        relations: ["captures.raw_amount"],
+      },
       sharedContext
     )
 
-    // TODO: revisit when https://github.com/medusajs/medusa/pull/6253 is merged
-    // if (payment.captured_amount < input.amount) {
-    //   throw new MedusaError(
-    //     MedusaError.Types.INVALID_DATA,
-    //     `Refund amount for payment: ${payment.id} cannot be greater than the amount captured on the payment.`
-    //   )
-    // }
+    if (!data.amount) {
+      data.amount = payment.amount as number
+    }
+
+    const capturedAmount = payment.captures.reduce((captureAmount, next) => {
+      const amountAsBigNumber = new BigNumber(next.raw_amount.value)
+      return captureAmount.plus(amountAsBigNumber)
+    }, BigNumber(0))
+    const refundAmount = BigNumber(data.amount)
+
+    if (capturedAmount.lt(refundAmount)) {
+      throw new MedusaError(
+        MedusaError.Types.INVALID_DATA,
+        `You cannot refund more than what is captured on the payment.`
+      )
+    }
 
     const paymentData = await this.paymentProviderService_.refundPayment(
       {