Make cash refunds reverse the sale instead of re-opening AR

Audit finding 9a: a cash refund posted DR AR (control up) while the customer
subledger went down — opposite directions, guaranteeing AR drift. Per the chosen
model, a cash refund now *reverses the sale*: DR Sales Returns (revenue portion)
+ DR Sales Tax Payable (tax portion) / CR Bank, with the customer AR balance left
untouched (the invoice stays paid; the sale is contra'd).

- New 4960 "Sales Returns & Allowances" contra-revenue account (seed + self-heal).
- Tax/revenue split centralized in Core RefundAllocation.Split so the posting and
  both reporting recomputes compute it identically (a mismatch would unbalance the
  trial balance).
- InvoicesController IssueRefund/CancelRefund: new posting + reversal; no AR/
  customer-balance change.
- LedgerService (per-account + prior balance): refunds debit Sales Returns + Sales
  Tax, no longer debit AR; bank credit unchanged.
- FinancialReportService: trial balance, balance sheet (retained earnings + tax
  liability), and P&L (contra-revenue line) all updated to match. Store-credit
  refunds are excluded everywhere (they post via CreditMemo, not the GL — 9b).

Verified: $108 refund (incl. $8 tax) -> bank -100... checks: assets -108 =
liabilities -8 + equity -100. New tests cover the split invariant and the ledger
postings. Build clean; 283 unit tests pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
2026-06-18 19:58:42 -04:00
parent f54b945053
commit 2a82a1d34b
7 changed files with 288 additions and 51 deletions
@@ -0,0 +1,29 @@
namespace PowderCoating.Core.Accounting;
/// <summary>
/// Single source of truth for splitting a customer refund into its revenue (returns) portion and
/// its sales-tax portion, under the "reverse the sale" model. A refund of a paid invoice reverses
/// the original sale: the revenue portion is debited to Sales Returns (contra-revenue) and the tax
/// portion is debited to Sales Tax Payable (reducing the liability), with cash credited out.
///
/// The split is proportional to the parent invoice's tax ratio so a partial refund reverses the
/// right amount of tax. Centralised here so the posting (<c>InvoicesController</c>) and the two
/// reporting recomputes (<c>LedgerService</c>, <c>FinancialReportService</c>) always agree — if they
/// computed it independently the trial balance could drift.
/// </summary>
public static class RefundAllocation
{
/// <summary>
/// Splits <paramref name="refundAmount"/> (tax-inclusive) into (returnsPortion, taxPortion) using
/// the parent invoice's tax ratio. When the invoice has no total or no tax, the whole refund is
/// the returns portion and the tax portion is zero.
/// </summary>
public static (decimal ReturnsPortion, decimal TaxPortion) Split(
decimal refundAmount, decimal invoiceTaxAmount, decimal invoiceTotal)
{
var taxPortion = invoiceTotal > 0m && invoiceTaxAmount > 0m
? Math.Round(refundAmount * invoiceTaxAmount / invoiceTotal, 2, MidpointRounding.AwayFromZero)
: 0m;
return (refundAmount - taxPortion, taxPortion);
}
}
@@ -1,6 +1,7 @@
using Microsoft.EntityFrameworkCore;
using PowderCoating.Application.DTOs.Accounting;
using PowderCoating.Application.Interfaces;
using PowderCoating.Core.Accounting;
using PowderCoating.Core.Entities;
using PowderCoating.Core.Enums;
using PowderCoating.Infrastructure.Data;
@@ -47,6 +48,14 @@ public class FinancialReportService : IFinancialReportService
.SumAsync(p => (decimal?)p.Amount) ?? 0;
if (cashRevenue > 0)
revenueLines.Add(new FinancialReportLine { AccountNumber = "—", AccountName = "Cash Receipts", Amount = cashRevenue });
// Cash refunds are cash paid back out — they reduce cash-basis revenue.
var cashRefunds = await _context.Refunds
.Where(r => !r.IsDeleted && r.RefundMethod != PaymentMethod.StoreCredit
&& r.RefundDate >= from && r.RefundDate <= toEnd)
.SumAsync(r => (decimal?)r.Amount) ?? 0m;
if (cashRefunds > 0)
revenueLines.Add(new FinancialReportLine { AccountNumber = "4960", AccountName = "Less: Refunds Paid", Amount = -cashRefunds });
}
else
{
@@ -98,6 +107,22 @@ public class FinancialReportService : IFinancialReportService
Amount = -totalDeductions
});
// Cash refunds reverse the sale — the revenue portion is contra-revenue (the tax portion
// relieves Sales Tax Payable, not revenue). Store-credit refunds are excluded (no GL posting).
var periodRefunds = await _context.Refunds
.Where(r => !r.IsDeleted && r.Invoice != null && r.RefundMethod != PaymentMethod.StoreCredit
&& r.RefundDate >= from && r.RefundDate <= toEnd)
.Select(r => new { r.Amount, r.Invoice!.TaxAmount, r.Invoice.Total })
.ToListAsync();
var periodRefundReturns = periodRefunds.Sum(r => RefundAllocation.Split(r.Amount, r.TaxAmount, r.Total).ReturnsPortion);
if (periodRefundReturns > 0)
revenueLines.Add(new FinancialReportLine
{
AccountNumber = "4960",
AccountName = "Less: Sales Returns",
Amount = -periodRefundReturns
});
// GC sales are deferred to GC Liability at issuance; revenue is recognized on redemption.
var periodGcReclassified = await _context.InvoiceItems
.Where(ii => ii.IsGiftCertificate
@@ -274,10 +299,23 @@ public class FinancialReportService : IFinancialReportService
arCredits += await _context.CreditMemoApplications
.Where(a => a.AppliedDate <= asOfEnd && a.Invoice.Status != InvoiceStatus.Voided)
.SumAsync(a => (decimal?)a.AmountApplied) ?? 0;
// Refunds reverse collected payments — they re-open AR so reduce net AR credits.
arCredits -= await _context.Refunds
.Where(r => r.RefundDate <= asOfEnd && !r.IsDeleted)
.SumAsync(r => (decimal?)r.Amount) ?? 0m;
// Cash refunds reverse the sale: revenue portion reduces retained earnings (Sales Returns),
// tax portion relieves Sales Tax Payable, cash leaves the bank (refundsByAcctBs). AR is untouched.
// Store-credit refunds post via CreditMemo, not the GL, so are excluded.
var saleReversingRefundsBs = await _context.Refunds
.Where(r => r.RefundDate <= asOfEnd && !r.IsDeleted && r.Invoice != null
&& r.RefundMethod != PaymentMethod.StoreCredit)
.Select(r => new { r.Amount, r.Invoice!.TaxAmount, r.Invoice.Total, r.Invoice.SalesTaxAccountId })
.ToListAsync();
decimal refundReturnsTotalBs = 0m;
var refundTaxByAcctBs = new Dictionary<int, decimal>();
foreach (var r in saleReversingRefundsBs)
{
var (returnsPortion, taxPortion) = RefundAllocation.Split(r.Amount, r.TaxAmount, r.Total);
refundReturnsTotalBs += returnsPortion;
if (taxPortion != 0m && r.SalesTaxAccountId.HasValue)
refundTaxByAcctBs[r.SalesTaxAccountId.Value] = refundTaxByAcctBs.GetValueOrDefault(r.SalesTaxAccountId.Value) + taxPortion;
}
// Refunds by bank account: money that left the account (CR to checking/bank).
var refundsByAcctBs = await _context.Refunds
@@ -390,6 +428,7 @@ public class FinancialReportService : IFinancialReportService
var retainedEarnings = lifetimeRevenue + jeRevNet
- lifetimeDiscounts
- lifetimeCreditMemos
- refundReturnsTotalBs // revenue portion of cash refunds (reversed sales)
- lifetimeGcReclassified // deferred to GC Liability, not earned yet
+ lifetimeGcBreakage // breakage income when GC voided with balance
- lifetimeDirectExp
@@ -425,6 +464,7 @@ public class FinancialReportService : IFinancialReportService
credits += taxByAcct.GetValueOrDefault(a.Id);
credits += refundsByAcctBs.GetValueOrDefault(a.Id); // refunds reduce bank balance
debits += depositsByAcctDepBs.GetValueOrDefault(a.Id); // deposits increase bank balance
debits += refundTaxByAcctBs.GetValueOrDefault(a.Id); // refund tax portion relieves the tax liability
if (gcLiabilityAcctIdBs.HasValue && a.Id == gcLiabilityAcctIdBs.Value)
{
credits += gcLiabilityCreditsBs; // GC issued → CR liability
@@ -990,11 +1030,28 @@ public class FinancialReportService : IFinancialReportService
.SumAsync(p => (decimal?)p.Amount) ?? 0m;
arTotalCredits += cmApplied; // credit memo applications reduce AR balance
// Refunds reverse collected payments — reduce net AR credits (re-opens the receivable).
var refundTotal = await _context.Refunds
.Where(r => r.RefundDate <= asOfEnd && !r.IsDeleted)
.SumAsync(r => (decimal?)r.Amount) ?? 0m;
arTotalCredits -= refundTotal;
// Cash refunds reverse the sale: revenue portion → DR Sales Returns (4960), tax portion →
// DR Sales Tax Payable (relieves the liability), cash → CR bank (refundsByAcct below). They no
// longer touch AR. Store-credit refunds post via CreditMemo, not the GL, so are excluded.
var saleReversingRefunds = await _context.Refunds
.Where(r => r.RefundDate <= asOfEnd && !r.IsDeleted && r.Invoice != null
&& r.RefundMethod != PaymentMethod.StoreCredit)
.Select(r => new { r.Amount, r.Invoice!.TaxAmount, r.Invoice.Total, r.Invoice.SalesTaxAccountId })
.ToListAsync();
decimal refundReturnsTotal = 0m;
var refundTaxByAcct = new Dictionary<int, decimal>();
foreach (var r in saleReversingRefunds)
{
var (returnsPortion, taxPortion) = RefundAllocation.Split(r.Amount, r.TaxAmount, r.Total);
refundReturnsTotal += returnsPortion;
if (taxPortion != 0m && r.SalesTaxAccountId.HasValue)
refundTaxByAcct[r.SalesTaxAccountId.Value] = refundTaxByAcct.GetValueOrDefault(r.SalesTaxAccountId.Value) + taxPortion;
}
var salesReturnsAcctId = await _context.Accounts
.Where(a => a.CompanyId == companyId && a.AccountNumber == "4960" && a.IsActive && !a.IsDeleted)
.Select(a => (int?)a.Id).FirstOrDefaultAsync();
// Refunds by bank account: money leaving the account (CR to checking/bank).
var refundsByAcct = await _context.Refunds
@@ -1079,6 +1136,9 @@ public class FinancialReportService : IFinancialReportService
debits += discountsByAcct.GetValueOrDefault(a.Id);
credits += refundsByAcct.GetValueOrDefault(a.Id); // refunds reduce bank balance
debits += depositsByAcctDep.GetValueOrDefault(a.Id); // deposits increase bank balance
if (salesReturnsAcctId.HasValue && a.Id == salesReturnsAcctId.Value)
debits += refundReturnsTotal; // revenue portion of cash refunds
debits += refundTaxByAcct.GetValueOrDefault(a.Id); // tax portion relieves the tax liability
if (gcLiabilityAcctId.HasValue && a.Id == gcLiabilityAcctId.Value)
{
credits += gcLiabilityCredits; // GC issued → CR liability
@@ -2,6 +2,7 @@ using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using PowderCoating.Application.DTOs.Accounting;
using PowderCoating.Application.Interfaces;
using PowderCoating.Core.Accounting;
using PowderCoating.Core.Enums;
using PowderCoating.Infrastructure.Data;
@@ -199,6 +200,43 @@ public class LedgerService : ILedgerService
LinkId = inv.Id
});
// ── 5b. Cash refunds reverse the sale (DR Sales Returns 4960 + DR Sales Tax Payable) ──
// The revenue portion debits Sales Returns; the tax portion debits the invoice's sales-tax
// account (relieving the liability). Cash leaving the bank is handled in the bank section above.
// Store-credit refunds are excluded — they post via CreditMemo, not the GL (see CancelRefund).
if (account.AccountNumber == "4960" || account.AccountType == AccountType.Liability)
{
var saleReversingRefunds = await _context.Refunds
.Include(r => r.Invoice)
.Where(r => !r.IsDeleted && r.Invoice != null
&& r.RefundMethod != PaymentMethod.StoreCredit
&& r.RefundDate >= fromDate && r.RefundDate <= toDate)
.ToListAsync();
foreach (var r in saleReversingRefunds)
{
var (returnsPortion, taxPortion) = RefundAllocation.Split(r.Amount, r.Invoice.TaxAmount, r.Invoice.Total);
if (account.AccountNumber == "4960" && returnsPortion != 0)
entries.Add(new LedgerEntryDto
{
Date = r.RefundDate, Reference = r.Reference ?? $"REF-{r.Id}", Source = "Refund",
Description = $"Sales return — {r.Invoice.InvoiceNumber}",
Debit = returnsPortion, Credit = 0,
LinkController = "Invoices", LinkId = r.InvoiceId
});
if (r.Invoice.SalesTaxAccountId == accountId && taxPortion != 0)
entries.Add(new LedgerEntryDto
{
Date = r.RefundDate, Reference = r.Reference ?? $"REF-{r.Id}", Source = "Refund",
Description = $"Tax refunded — {r.Invoice.InvoiceNumber}",
Debit = taxPortion, Credit = 0,
LinkController = "Invoices", LinkId = r.InvoiceId
});
}
}
// ── 6. Direct expenses categorized to this account (DEBIT) ────────────
// e.g. Expense account 6200 receives direct expense entries
var expensesTo = await _context.Expenses
@@ -312,24 +350,8 @@ public class LedgerService : ILedgerService
LinkId = cm.InvoiceId
});
// Refunds re-open AR (DEBIT — customer owes again after refund)
var arRefunds = await _context.Refunds
.Include(r => r.Invoice)
.Where(r => r.RefundDate >= fromDate && r.RefundDate <= toDate && !r.IsDeleted)
.ToListAsync();
foreach (var r in arRefunds)
entries.Add(new LedgerEntryDto
{
Date = r.RefundDate,
Reference = r.Reference ?? $"REF-{r.Id}",
Source = "Refund",
Description = r.Reason,
Debit = r.Amount,
Credit = 0,
LinkController = "Invoices",
LinkId = r.InvoiceId
});
// NOTE: cash refunds no longer touch AR. Under the "reverse the sale" model they debit
// Sales Returns + Sales Tax Payable and credit the bank (see section 5b above).
}
// ── 9. Accounts Payable ────────────────────────────────────────────────
@@ -594,6 +616,27 @@ public class LedgerService : ILedgerService
&& i.InvoiceDate < beforeDate)
.SumAsync(i => (decimal?)i.TaxAmount) ?? 0;
// 5b. Cash refunds reverse the sale (DR Sales Returns 4960 + DR Sales Tax Payable). Store-credit
// refunds are excluded (no GL posting). Mirrors section 5b in GetAccountLedgerAsync.
if (account.AccountNumber == "4960" || account.AccountType == AccountType.Liability)
{
var priorRefunds = await _context.Refunds
.Include(r => r.Invoice)
.Where(r => !r.IsDeleted && r.Invoice != null
&& r.RefundMethod != PaymentMethod.StoreCredit
&& r.RefundDate < beforeDate)
.ToListAsync();
foreach (var r in priorRefunds)
{
var (returnsPortion, taxPortion) = RefundAllocation.Split(r.Amount, r.Invoice.TaxAmount, r.Invoice.Total);
if (account.AccountNumber == "4960")
debits += returnsPortion;
if (r.Invoice.SalesTaxAccountId == accountId)
debits += taxPortion;
}
}
// 6. Direct expenses categorized to this account (DEBIT)
debits += await _context.Expenses
.Where(e => e.ExpenseAccountId == accountId && e.Date < beforeDate)
@@ -624,9 +667,8 @@ public class LedgerService : ILedgerService
.Where(a => a.AppliedDate < beforeDate && a.Invoice.Status != InvoiceStatus.Voided)
.SumAsync(a => (decimal?)a.AmountApplied) ?? 0;
debits += await _context.Refunds
.Where(r => !r.IsDeleted && r.RefundDate < beforeDate)
.SumAsync(r => (decimal?)r.Amount) ?? 0;
// NOTE: cash refunds no longer debit AR — they reverse the sale (Sales Returns + Sales Tax),
// handled in section 5b above.
}
// 9. Accounts Payable
@@ -77,6 +77,7 @@ public partial class SeedDataService
// A credit-normal account with a debit balance appears in the Trial Balance debit column,
// reducing net revenue to match the discounted AR amount that was posted.
new Account { AccountNumber = "4950", Name = "Sales Discounts", AccountType = AccountType.Revenue, AccountSubType = AccountSubType.OtherIncome, IsSystem = true, IsActive = true, Description = "Contra-revenue for invoice discounts granted to customers", CompanyId = company.Id, CreatedAt = now },
new Account { AccountNumber = "4960", Name = "Sales Returns & Allowances", AccountType = AccountType.Revenue, AccountSubType = AccountSubType.OtherIncome, IsSystem = true, IsActive = true, Description = "Contra-revenue for the revenue portion of customer refunds (reversed sales)", CompanyId = company.Id, CreatedAt = now },
// ── COST OF GOODS SOLD ────────────────────────────────────────────
new Account { AccountNumber = "5000", Name = "Cost of Goods Sold", AccountType = AccountType.CostOfGoods, AccountSubType = AccountSubType.CostOfGoodsSold, IsSystem = false, IsActive = true, Description = "Direct cost of services delivered", CompanyId = company.Id, CreatedAt = now },
@@ -141,6 +142,30 @@ public partial class SeedDataService
added++;
}
// 4960 Sales Returns & Allowances — contra-revenue account that receives the revenue portion
// of customer refunds under the "reverse the sale" model (DR Sales Returns + DR Sales Tax / CR Bank).
var has4960 = await _context.Set<Account>()
.IgnoreQueryFilters()
.AnyAsync(a => a.CompanyId == company.Id && a.AccountNumber == "4960" && !a.IsDeleted);
if (!has4960)
{
_context.Set<Account>().Add(new Account
{
AccountNumber = "4960",
Name = "Sales Returns & Allowances",
AccountType = AccountType.Revenue,
AccountSubType = AccountSubType.OtherIncome,
IsSystem = true,
IsActive = true,
Description = "Contra-revenue for the revenue portion of customer refunds (reversed sales)",
CompanyId = company.Id,
CreatedAt = now
});
await _context.SaveChangesAsync();
added++;
}
return added;
}
}
@@ -7,6 +7,7 @@ using PowderCoating.Application.DTOs.Common;
using PowderCoating.Application.DTOs.Invoice;
using PowderCoating.Application.DTOs.Quote;
using PowderCoating.Application.Interfaces;
using PowderCoating.Core.Accounting;
using PowderCoating.Core.Entities;
using Microsoft.AspNetCore.Mvc.Rendering;
using PowderCoating.Core.Enums;
@@ -2485,6 +2486,14 @@ public class InvoicesController : Controller
return acct?.Id;
}
/// <summary>Returns the Sales Returns &amp; Allowances contra-revenue account (4960) for refunds.</summary>
private async Task<int?> GetSalesReturnsAccountIdAsync(int companyId)
{
var acct = await _unitOfWork.Accounts.FirstOrDefaultAsync(
a => a.IsActive && a.AccountNumber == "4960");
return acct?.Id;
}
/// <summary>Returns the AR account ID for the given company (first active AccountsReceivable account).</summary>
private async Task<int?> GetArAccountIdAsync(int companyId)
{
@@ -2667,20 +2676,20 @@ public class InvoicesController : Controller
}
else
{
// Adjust customer AR balance — they're owed money back
if (invoice.Customer != null)
{
invoice.Customer.CurrentBalance -= dto.Amount;
await _unitOfWork.Customers.UpdateAsync(invoice.Customer);
}
// "Reverse the sale": a cash refund contra's the original sale instead of re-opening AR.
// GL: DR Sales Returns (revenue portion) + DR Sales Tax Payable (tax portion) / CR Bank.
// Customer AR balance is intentionally left unchanged — the invoice stays paid and the
// sale is reversed via the contra accounts. The split is centralised in RefundAllocation
// so LedgerService and FinancialReportService recompute the same way.
await _unitOfWork.CompleteAsync();
// GL: DR AR (un-collects the payment) / CR Bank (cash leaves).
// Mirrors how FinancialReportService accounts for refunds:
// arTotalCredits -= refundTotal; refundsByAcct credits the bank account.
var arAccountId = await GetArAccountIdAsync(companyId);
await _accountBalanceService.DebitAsync(arAccountId, dto.Amount);
var (returnsPortion, taxPortion) = RefundAllocation.Split(dto.Amount, invoice.TaxAmount, invoice.Total);
var salesReturnsAccountId = await GetSalesReturnsAccountIdAsync(companyId);
var salesTaxAccountId = invoice.SalesTaxAccountId ?? await ResolveSalesTaxAccountIdAsync(companyId);
await _accountBalanceService.DebitAsync(salesReturnsAccountId, returnsPortion);
if (taxPortion > 0)
await _accountBalanceService.DebitAsync(salesTaxAccountId, taxPortion);
await _accountBalanceService.CreditAsync(dto.DepositAccountId, dto.Amount);
TempData["Success"] = $"Refund of {dto.Amount:C} recorded successfully. Please issue the refund manually.";
@@ -2751,16 +2760,15 @@ public class InvoicesController : Controller
}
else
{
// Reverse the AR balance adjustment
if (customer != null)
{
customer.CurrentBalance += refund.Amount;
await _unitOfWork.Customers.UpdateAsync(customer);
}
// Reverse the "reverse the sale" posting: CR Sales Returns + CR Sales Tax Payable / DR Bank.
// The customer's AR balance was not touched when the refund was issued, so it is not touched here.
var (returnsPortion, taxPortion) = RefundAllocation.Split(refund.Amount, refund.Invoice.TaxAmount, refund.Invoice.Total);
var salesReturnsAccountId = await GetSalesReturnsAccountIdAsync(refund.Invoice.CompanyId);
var salesTaxAccountId = refund.Invoice.SalesTaxAccountId ?? await ResolveSalesTaxAccountIdAsync(refund.Invoice.CompanyId);
// GL reversal: CR AR / DR Bank — mirrors the DR AR / CR Bank posted in IssueRefund.
var arAccountId = await GetArAccountIdAsync(refund.Invoice.CompanyId);
await _accountBalanceService.CreditAsync(arAccountId, refund.Amount);
await _accountBalanceService.CreditAsync(salesReturnsAccountId, returnsPortion);
if (taxPortion > 0)
await _accountBalanceService.CreditAsync(salesTaxAccountId, taxPortion);
await _accountBalanceService.DebitAsync(refund.DepositAccountId, refund.Amount);
}
@@ -509,6 +509,57 @@ public class LedgerServiceTests
// ── Helpers ───────────────────────────────────────────────────────────
// ── Cash refund reverses the sale: Sales Returns + Sales Tax debited, AR untouched ──
[Fact]
public async Task GetAccountLedgerAsync_CashRefund_ReversesTheSale_DebitsReturnsAndTax_NotAr()
{
await using var context = CreateContext();
context.Accounts.Add(new Account { Id = 1, CompanyId = 1, AccountNumber = "1000", Name = "Checking", AccountType = AccountType.Asset, AccountSubType = AccountSubType.Checking, IsActive = true });
context.Accounts.Add(new Account { Id = 2, CompanyId = 1, AccountNumber = "1100", Name = "AR", AccountType = AccountType.Asset, AccountSubType = AccountSubType.AccountsReceivable, IsActive = true });
context.Accounts.Add(new Account { Id = 3, CompanyId = 1, AccountNumber = "2200", Name = "Sales Tax Payable", AccountType = AccountType.Liability, AccountSubType = AccountSubType.OtherCurrentLiability, IsActive = true });
context.Accounts.Add(new Account { Id = 4, CompanyId = 1, AccountNumber = "4960", Name = "Sales Returns", AccountType = AccountType.Revenue, AccountSubType = AccountSubType.OtherIncome, IsActive = true });
// Invoice $108 incl. $8 tax, tax posted to account 3.
context.Invoices.Add(new Invoice
{
Id = 99, CompanyId = 1, InvoiceNumber = "INV-0099", CustomerId = 1,
Status = InvoiceStatus.Sent, InvoiceDate = InPeriod,
Total = 108m, TaxAmount = 8m, SalesTaxAccountId = 3
});
// Full cash refund of $108 paid from Checking.
context.Refunds.Add(new Refund
{
Id = 1, CompanyId = 1, InvoiceId = 99, Amount = 108m,
RefundDate = InPeriod, RefundMethod = PaymentMethod.Check, DepositAccountId = 1
});
await context.SaveChangesAsync();
var svc = CreateService(context);
// Sales Returns (4960): revenue portion debited ($100).
var returns = await svc.GetAccountLedgerAsync(4, PeriodStart, PeriodEnd);
var returnsEntry = Assert.Single(returns!.Entries, e => e.Source == "Refund");
Assert.Equal(100m, returnsEntry.Debit);
Assert.Equal(0m, returnsEntry.Credit);
// Sales Tax Payable: tax portion debited ($8), relieving the liability.
var tax = await svc.GetAccountLedgerAsync(3, PeriodStart, PeriodEnd);
var taxEntry = Assert.Single(tax!.Entries, e => e.Source == "Refund");
Assert.Equal(8m, taxEntry.Debit);
// Bank: full $108 credited (cash leaves).
var bank = await svc.GetAccountLedgerAsync(1, PeriodStart, PeriodEnd);
var bankEntry = Assert.Single(bank!.Entries, e => e.Source == "Refund");
Assert.Equal(108m, bankEntry.Credit);
// AR is no longer touched by refunds under the "reverse the sale" model.
var ar = await svc.GetAccountLedgerAsync(2, PeriodStart, PeriodEnd);
Assert.DoesNotContain(ar!.Entries, e => e.Source == "Refund");
}
private static LedgerService CreateService(ApplicationDbContext context)
=> new LedgerService(context, Mock.Of<ILogger<LedgerService>>());
@@ -0,0 +1,22 @@
using PowderCoating.Core.Accounting;
namespace PowderCoating.UnitTests;
public class RefundAllocationTests
{
[Theory]
[InlineData(108, 8, 108, 100, 8)] // full refund, proportional tax
[InlineData(54, 8, 108, 50, 4)] // half refund → half the tax
[InlineData(100, 0, 100, 100, 0)] // no tax on the invoice
[InlineData(100, 8, 0, 100, 0)] // zero invoice total → all returns, no tax
public void Split_AllocatesTaxProportionally_AndAlwaysSumsToRefund(
decimal amount, decimal invoiceTax, decimal invoiceTotal, decimal expectedReturns, decimal expectedTax)
{
var (returns, tax) = RefundAllocation.Split(amount, invoiceTax, invoiceTotal);
Assert.Equal(expectedReturns, returns);
Assert.Equal(expectedTax, tax);
// Invariant: the two portions must always reconstruct the refund exactly (no penny lost).
Assert.Equal(amount, returns + tax);
}
}