feat(backend): optional debitAmount increateOutgoingPaymentFromIncomingPayment mutation

packages/backend/src/graphql/schema.graphql

@@ -1246,7 +1246,7 @@ input CreateOutgoingPaymentFromIncomingPaymentInput {
   "Incoming payment URL to create the outgoing payment from."
   incomingPayment: String!
   "Amount to send (fixed send)."
-  debitAmount: AmountInput!
+  debitAmount: AmountInput
   "Additional metadata associated with the outgoing payment."
   metadata: JSONObject
   "Unique key to ensure duplicate or retried requests are processed only once. For more information, refer to [idempotency](https://rafiki.dev/apis/graphql/admin-api-overview/#idempotency)."

packages/backend/src/open_payments/payment/outgoing/service.ts

@@ -198,7 +198,7 @@ export interface CreateFromQuote extends BaseOptions {
 }
 export interface CreateFromIncomingPayment extends BaseOptions {
   incomingPayment: string
-  debitAmount: Amount
+  debitAmount?: Amount
 }
 
 export type CancelOutgoingPaymentOptions = {
@@ -214,7 +214,7 @@ export type CreateOutgoingPaymentOptions =
 export function isCreateFromIncomingPayment(
   options: CreateOutgoingPaymentOptions
 ): options is CreateFromIncomingPayment {
-  return 'incomingPayment' in options && 'debitAmount' in options
+  return 'incomingPayment' in options
 }
 
 async function cancelOutgoingPayment(
@@ -284,11 +284,10 @@ async function createOutgoingPayment(
             description: 'Time to create a quote in outgoing payment'
           }
         )
-        const { debitAmount, incomingPayment } = options
         const quoteOrError = await deps.quoteService.create({
           tenantId,
-          receiver: incomingPayment,
-          debitAmount,
+          receiver: options.incomingPayment,
+          debitAmount: options.debitAmount,
           method: 'ilp',
           walletAddressId
         })

packages/backend/src/open_payments/quote/service.test.ts

@@ -205,7 +205,7 @@ describe('QuoteService', (): void => {
         if (!debitAmount && !receiveAmount && !incomingAmount) {
           test('fails without receiver.incomingAmount', async (): Promise<void> => {
             await expect(quoteService.create(options)).resolves.toMatchObject({
-              type: QuoteErrorCode.InvalidReceiver
+              type: QuoteErrorCode.InvalidAmount
             })
           })
         } else {
@@ -552,6 +552,7 @@ describe('QuoteService', (): void => {
 
     test.each`
       debitAmount                              | receiveAmount                              | description
+      ${undefined}                             | ${undefined}                               | ${'with undefined debitAmount and receiveAmount'}
       ${{ ...debitAmount, value: BigInt(0) }}  | ${undefined}                               | ${'with debitAmount of zero'}
       ${{ ...debitAmount, value: BigInt(-1) }} | ${undefined}                               | ${'with negative debitAmount'}
       ${{ ...debitAmount, assetScale: 3 }}     | ${undefined}                               | ${'with wrong debitAmount asset'}

packages/backend/src/open_payments/quote/service.ts

@@ -345,9 +345,9 @@ export async function resolveReceiver(
         debitAmount: options.debitAmount,
         incomingAmount: receiver.incomingAmount
       },
-      'Could not create quote. debitAmount or incomingAmount required.'
+      'Could not create quote. One of receiveAmount, debitAmount or incomingAmount (on the incoming payment) is required.'
     )
-    throw new QuoteError(QuoteErrorCode.InvalidReceiver)
+    throw new QuoteError(QuoteErrorCode.InvalidAmount)
   }
   return receiver
 }