test: Unit & integration tests for PawaPayGateway

[teesofttech]

Overview

Add a complete unit and integration test suite for PawaPayGateway.

Gateway Details

• Class: PawaPayGateway
• Region: Africa mobile money — Ghana, Tanzania, Uganda, Rwanda, Zambia, DRC, Cameroon, Ivory Coast, etc.
• Networks: MTN MoMo, Airtel Money, M-Pesa, Orange Money, Tigo Pesa, Vodacom
• Auth: Bearer token (ApiToken)
• Sandbox URL: https://api.sandbox.pawapay.io
• Live URL: https://api.pawapay.io
• Tx Ref prefix: PP_
• Config: ApiToken, IsSandbox
• Enum: PaymentGatewayType.PawaPay = 14

Unit Tests (mocked HTTP)

Constructor

• Throws ArgumentNullException when config is null
• Uses sandbox URL when IsSandbox=true
• Uses live URL when IsSandbox=false

CreatePaymentAsync

• Posts to /deposits with correct payload (depositId, amount, currency, correspondent, payer.type, payer.address.value, statementDescription)
• Sets Authorization: Bearer header
• Tx reference starts with PP_
• Returns PaymentResponse.Success=true on status=ACCEPTED
• Returns PaymentResponse.Success=false on DUPLICATE_IGNORED or REJECTED

VerifyPaymentAsync

• Sends GET /deposits/{depositId}
• Returns IsSuccessful=true when status=COMPLETED
• Returns IsSuccessful=false for FAILED or TIMED_OUT

RefundPaymentAsync

• Posts to /refunds with correct payload
• Returns RefundResponse.IsSuccessful=true on ACCEPTED status

Integration Tests

Requires PAWAPAY_API_TOKEN env var (sandbox token)

• CreatePaymentAsync returns ACCEPTED status with depositId
• VerifyPaymentAsync returns correct status for a sandbox deposit

Files to Create

• PayBridge.SDK.Test/Unit/PawaPayGatewayTests.cs
• PayBridge.SDK.Test/Integration/PawaPayIntegrationTests.cs

Acceptance Criteria

• All unit tests pass with zero live HTTP calls
• Integration tests use [Trait("Category", "Integration")] and skip when env var is absent
• Code coverage >= 80% for PawaPayGateway.cs