Backfill cash ledger from historical transactions and add reconciliation QA (3d-32)

1 files changed, 43 insertions, 0 deletions

diff --git a/tests/FundLab.Api.Tests/CashReconciliationTests.fs b/tests/FundLab.Api.Tests/CashReconciliationTests.fs
index 59f6fd6..d8dc7bb 100644
--- a/tests/FundLab.Api.Tests/CashReconciliationTests.fs
+++ b/tests/FundLab.Api.Tests/CashReconciliationTests.fs
@@ -2,6 +2,7 @@ namespace FundLab.Api.Tests
 
 open System
 open System.Text.Json
+open Npgsql
 open Xunit
 open FundLab.Api
 open FundLab.Domain
@@ -201,6 +202,20 @@ type CashReconciliationTests(fixture: PostgresFixture) =
         |> Seq.filter (fun entry -> entry.GetProperty("source").GetString() = source)
         |> Seq.length
 
+    let deleteLedgerEvents fundId =
+        use connection = new NpgsqlConnection(fixture.ConnectionString)
+        connection.Open()
+        use command = new NpgsqlCommand("DELETE FROM cash_ledger_events WHERE fund_id = @fund_id", connection)
+        command.Parameters.AddWithValue("fund_id", fundId) |> ignore
+        command.ExecuteNonQuery() |> ignore
+
+    let ledgerEventCount fundId =
+        use connection = new NpgsqlConnection(fixture.ConnectionString)
+        connection.Open()
+        use command = new NpgsqlCommand("SELECT count(*) FROM cash_ledger_events WHERE fund_id = @fund_id", connection)
+        command.Parameters.AddWithValue("fund_id", fundId) |> ignore
+        command.ExecuteScalar() :?> int64
+
     [<Fact>]
     member _.``cash reconciliation balances across every source category``() =
         let fundId = createFund 10000.00m
@@ -252,3 +267,31 @@ type CashReconciliationTests(fixture: PostgresFixture) =
         let status, body = reconciliation (Guid.NewGuid())
         Assert.Equal(404, status)
         Assert.Contains("FUND_NOT_FOUND", body)
+
+    [<Fact>]
+    member _.``backfill rebuilds the ledger for history written before it existed``() =
+        let fundId = createFund 10000.00m
+        deposit fundId 5000.00m (fixture.Key "cash-backfill-deposit")
+        buyStockDebit fundId "600519" 100m 10.00m (fixture.Key "cash-backfill-buy")
+        sellStock fundId "600519" 40m 10.00m (fixture.Key "cash-backfill-sell")
+        buyBond fundId "110075" 10m 100.00m
+        recordBondCoupon fundId "110075" 50.00m (fixture.Key "cash-backfill-coupon")
+        subscribe fundId (seedInstrument ()) 1000.00m (fixture.Key "cash-backfill-subscribe")
+
+        // deposit + stock buy + stock sell + bond coupon + subscription settle
+        let expected = 5L
+
+        // simulate a database that predates the ledger: drop the hook-written events
+        deleteLedgerEvents fundId
+        Assert.Equal(0L, ledgerEventCount fundId)
+
+        repository().BackfillCashLedger() |> ignore
+
+        Assert.Equal(expected, ledgerEventCount fundId)
+        Assert.Equal(0.00m, (repository().GetCashReconciliation fundId |> Result.defaultWith failwith).Difference)
+
+        // re-running must be a no-op: same event count, same reconciled balance
+        repository().BackfillCashLedger() |> ignore
+
+        Assert.Equal(expected, ledgerEventCount fundId)
+        Assert.Equal(0.00m, (repository().GetCashReconciliation fundId |> Result.defaultWith failwith).Difference)