README
¶
Ledger
It is a conceptual Ledger for storing payments. It exposes the following endpoints over gRPC:
CreatePaymentto create a new payment.ReadPaymentto get all information about a payment.ReadPaymentUsingBankReferenceto get all information about a payment using the bank reference.UpdatePaymentToPendingto inform that a payment was sent to an Acquiring Bank.UpdatePaymentToSuccessto inform that a payment was successfully executed by an Acquiring Bank.UpdatePaymentToFailto set the payment as a failure, if refused by the bank, a message is expected to infrom the reason.
The validation of fields is very simple, it is not truly checking credit card number, or currencies. The idea is to get something minimal working, but that can be extended and improved later.
Data Model
Internally there is an in memory database which is a hash table with all payments keyed by their ids, and an extra hash table to map bank reference ids to the ledger ids. The idea is that the bank will issue an id of its own while processing the payment.
type Payment struct {
ID uuid.UUID
MerchantID uuid.UUID
Amount float64
Currency string
PurchaseTime time.Time
ValidationMethod string
Card CreditCard
Metadata string
Status PaymentStatus
BankPaymentID uuid.UUID
BankRequestTime time.Time
BankResponseTime time.Time
BankMessage string
}
Testing
Unit tests
Please run the unit tests as follows:
$ go test -v ./... -coverprofile=coverage.out
And check the coverage (currently ~74%):
$ go tool cover -func=coverage.out
Manual testing
These tests should later be automated as integrations tests, but for now please use the grpcurl tool to verify that the endpoints are working as expected.
- Create a valid payment
$ grpcurl -plaintext -d '{"merchant_id": "e1211351-bb91-441f-9ea0-3b243189dec6", "amount": 150.0, "currency": "USD", "purchase_time_utc": "2023-05-18T05:00:10.000", "validation_method": "sms", "card": {"number": "1111-2222-3333-4444", "name": "name surname", "expire_month": 10, "expire_year": 2099, "cvv": 123}, "metadata": "shopper:123"}' "0.0.0.0:50053" ledger.LedgerService/CreatePayment
{
"id": "35947b97-1cf3-4f5c-aa23-3ee0b9734ff7"
}
- Create an invalid payment - negative amount
$ grpcurl -plaintext -d '{"merchant_id": "e1211351-bb91-441f-9ea0-3b243189dec6", "amount": -150.0, "currency": "USD", "purchase_time_utc": "2023-05-18T05:00:10.000", "validation_method": "sms", "card": {"number": "1111-2222-3333-4444", "name": "name surname", "expire_month": 10, "expire_year": 2099, "cvv": 123}, "metadata": "shopper:123"}' "0.0.0.0:50053" ledger.LedgerService/CreatePayment
ERROR:
Code: Unknown
Message: negative amount
- Create an invalid payment - card expired
$ grpcurl -plaintext -d '{"merchant_id": "e1211351-bb91-441f-9ea0-3b243189dec6", "amount": 150.0, "currency": "USD", "purchase_time_utc": "2023-05-18T05:00:10.000", "validation_method": "sms", "card": {"number": "1111-2222-3333-4444", "name": "name surname", "expire_month": 10, "expire_year": 2020, "cvv": 123}, "metadata": "shopper:123"}' "0.0.0.0:50053" ledger.LedgerService/CreatePayment
ERROR:
Code: Unknown
Message: invalid expiration
- Read existing payment
$ grpcurl -plaintext -d '{"id": "35947b97-1cf3-4f5c-aa23-3ee0b9734ff7"}' "0.0.0.0:50053" ledger.LedgerService/ReadPayment
{
"payment": {
"id": "35947b97-1cf3-4f5c-aa23-3ee0b9734ff7",
"merchantId": "e1211351-bb91-441f-9ea0-3b243189dec6",
"amount": 150,
"currency": "USD",
"purchaseTimeUtc": "2023-05-18T05:00:10.000",
"validationMethod": "sms",
"card": {
"number": "1111-2222-3333-4444",
"name": "name surname",
"expireMonth": 10,
"expireYear": 2099,
"cvv": 123
},
"metadata": "shopper:123",
"bankPaymentId": "00000000-0000-0000-0000-000000000000",
"bankRequestTimeUtc": "0001-01-01T00:00:00.000",
"bankResponseTimeUtc": "0001-01-01T00:00:00.000"
}
}
- Read unexisting payment
$ grpcurl -plaintext -d '{"id": "e1211351-bb91-441f-9ea0-3b243189dec6"}' "0.0.0.0:50053" ledger.LedgerService/ReadPayment
ERROR:
Code: Unknown
Message: there is no payment with given id
- Update payment to pending
$ grpcurl -plaintext -d '{"id": "35947b97-1cf3-4f5c-aa23-3ee0b9734ff7", "bank_payment_id": "70580f0a-8478-4aba-8ccf-3de1e1df665c", "bank_request_time_utc": "2023-05-18T05:01:10.000"}' "0.0.0.0:50053" ledger.LedgerService/UpdatePaymentToPending
{
}
$ grpcurl -plaintext -d '{"id": "35947b97-1cf3-4f5c-aa23-3ee0b9734ff7"}' "0.0.0.0:50053" ledger.LedgerService/ReadPayment
{
"payment": {
"id": "35947b97-1cf3-4f5c-aa23-3ee0b9734ff7",
"merchantId": "e1211351-bb91-441f-9ea0-3b243189dec6",
"amount": 150,
"currency": "USD",
"purchaseTimeUtc": "2023-05-18T05:00:10.000",
"validationMethod": "sms",
"card": {
"number": "1111-2222-3333-4444",
"name": "name surname",
"expireMonth": 10,
"expireYear": 2099,
"cvv": 123
},
"metadata": "shopper:123",
"status": "PENDING",
"bankPaymentId": "70580f0a-8478-4aba-8ccf-3de1e1df665c",
"bankRequestTimeUtc": "2023-05-18T05:01:10.000",
"bankResponseTimeUtc": "0001-01-01T00:00:00.000"
}
}
- Update payment to success
$ grpcurl -plaintext -d '{"id": "35947b97-1cf3-4f5c-aa23-3ee0b9734ff7", "bank_payment_id": "70580f0a-8478-4aba-8ccf-3de1e1df665c", "bank_response_time_utc": "2023-05-18T05:02:10.000", "bank_message": "success"}' "0.0.0.0:50053" ledger.LedgerService/UpdatePaymentToSuccess
{
}
$ grpcurl -plaintext -d '{"id": "35947b97-1cf3-4f5c-aa23-3ee0b9734ff7"}' "0.0.0.0:50053" ledger.LedgerService/ReadPayment
{
"payment": {
"id": "35947b97-1cf3-4f5c-aa23-3ee0b9734ff7",
"merchantId": "e1211351-bb91-441f-9ea0-3b243189dec6",
"amount": 150,
"currency": "USD",
"purchaseTimeUtc": "2023-05-18T05:00:10.000",
"validationMethod": "sms",
"card": {
"number": "1111-2222-3333-4444",
"name": "name surname",
"expireMonth": 10,
"expireYear": 2099,
"cvv": 123
},
"metadata": "shopper:123",
"status": "SUCCESS",
"bankPaymentId": "70580f0a-8478-4aba-8ccf-3de1e1df665c",
"bankRequestTimeUtc": "2023-05-18T05:01:10.000",
"bankResponseTimeUtc": "2023-05-18T05:02:10.000",
"bankMessage": "success"
}
}
- Update payment to fail
$ grpcurl -plaintext -d '{"merchant_id": "e1211351-bb91-441f-9ea0-3b243189dec6", "amount": 150.0, "currency": "USD", "purchase_time_utc": "2023-05-18T05:00:10.000", "validation_method": "sms", "card": {"number": "1111-2222-3333-4444", "name": "name surname", "expire_month": 10, "expire_year": 2029, "cvv": 123}, "metadata": "shopper:123"}' "0.0.0.0:50053" ledger.LedgerService/CreatePayment
{
"id": "dbb2c818-ec5f-4dac-ad2a-a6b021c981bf"
}
$ grpcurl -plaintext -d '{"id": "dbb2c818-ec5f-4dac-ad2a-a6b021c981bf", "bank_payment_id": "70580f0a-8478-4aba-8ccf-3de1e1df665c", "bank_response_time_utc": "2023-05-18T05:02:10.000", "bank_message": "could not reach shopper"}' "0.0.0.0:50053" ledger.LedgerService/UpdatePaymentToFail
{
}
$ grpcurl -plaintext -d '{"id": "dbb2c818-ec5f-4dac-ad2a-a6b021c981bf"}' "0.0.0.0:50053" ledger.LedgerService/ReadPayment
{
"payment": {
"id": "dbb2c818-ec5f-4dac-ad2a-a6b021c981bf",
"merchantId": "e1211351-bb91-441f-9ea0-3b243189dec6",
"amount": 150,
"currency": "USD",
"purchaseTimeUtc": "2023-05-18T05:00:10.000",
"validationMethod": "sms",
"card": {
"number": "1111-2222-3333-4444",
"name": "name surname",
"expireMonth": 10,
"expireYear": 2029,
"cvv": 123
},
"metadata": "shopper:123",
"status": "FAIL",
"bankPaymentId": "70580f0a-8478-4aba-8ccf-3de1e1df665c",
"bankRequestTimeUtc": "0001-01-01T00:00:00.000",
"bankResponseTimeUtc": "2023-05-18T05:02:10.000",
"bankMessage": "could not reach shopper"
}
}
- Read using bank payment id
$ grpcurl -plaintext -d '{"merchant_id": "e1211351-bb91-441f-9ea0-3b243189dec6", "amount": 150.0, "currency": "USD", "purchase_time_utc": "2023-05-18T05:00:10.000", "validation_method": "sms", "card": {"number": "1111-2222-3333-4444", "name": "name surname", "expire_month": 10, "expire_year": 2029, "cvv": 123}, "metadata": "shopper:123"}' "0.0.0.0:50053" ledger.LedgerService/CreatePayment
{
"id": "ac5503cc-3018-4484-90e1-0bcc64c91f63"
}
$ grpcurl -plaintext -d '{"id": "ac5503cc-3018-4484-90e1-0bcc64c91f63", "bank_payment_id": "70580f0a-8478-4aba-8ccf-3de1e1df665c", "bank_response_time_utc": "2023-05-18T05:02:10.000", "bank_message": "success"}' "0.0.0.0:50053" ledger.LedgerService/UpdatePaymentToSuccess
{
}
$ grpcurl -plaintext -d '{"id": "70580f0a-8478-4aba-8ccf-3de1e1df665c"}' "0.0.0.0:50053" ledger.LedgerService/ReadPaymentUsingBankReference
{
"payment": {
"id": "ac5503cc-3018-4484-90e1-0bcc64c91f63",
"merchantId": "e1211351-bb91-441f-9ea0-3b243189dec6",
"amount": 150,
"currency": "USD",
"purchaseTimeUtc": "2023-05-18T05:00:10.000",
"validationMethod": "sms",
"card": {
"number": "1111-2222-3333-4444",
"name": "name surname",
"expireMonth": 10,
"expireYear": 2029,
"cvv": 123
},
"metadata": "shopper:123",
"status": "SUCCESS",
"bankPaymentId": "70580f0a-8478-4aba-8ccf-3de1e1df665c",
"bankRequestTimeUtc": "0001-01-01T00:00:00.000",
"bankResponseTimeUtc": "2023-05-18T05:02:10.000",
"bankMessage": "success"
}
}
Documentation
¶
There is no documentation for this package.
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