feat: transfer funds between accounts

internal/repository/transaction_test.go

@@ -0,0 +1,113 @@
+package repository
+
+import (
+	"testing"
+	"time"
+
+	"git.juancwu.dev/juancwu/budgit/internal/model"
+	"git.juancwu.dev/juancwu/budgit/internal/testutil"
+	"github.com/google/uuid"
+	"github.com/shopspring/decimal"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestTransactionRepository_TransferAtomic_LinksPairAndUpdatesBalances(t *testing.T) {
+	testutil.ForEachDB(t, func(t *testing.T, dbi testutil.DBInfo) {
+		repo := NewTransactionRepository(dbi.DB)
+
+		user := testutil.CreateTestUser(t, dbi.DB, "transfer-repo@example.com", nil)
+		space := testutil.CreateTestSpace(t, dbi.DB, user.ID, "S")
+		src := testutil.CreateTestAccount(t, dbi.DB, space.ID, "Src")
+		dst := testutil.CreateTestAccount(t, dbi.DB, space.ID, "Dst")
+
+		now := time.Now()
+		withdrawal := &model.Transaction{
+			ID: uuid.NewString(), Value: decimal.NewFromInt(40), Type: model.TransactionTypeWithdrawal,
+			AccountID: src.ID, Title: "Move", OccurredAt: now, CreatedAt: now, UpdatedAt: now,
+		}
+		deposit := &model.Transaction{
+			ID: uuid.NewString(), Value: decimal.NewFromInt(40), Type: model.TransactionTypeDeposit,
+			AccountID: dst.ID, Title: "Move", OccurredAt: now, CreatedAt: now, UpdatedAt: now,
+		}
+
+		err := repo.TransferAtomic(withdrawal, deposit, decimal.NewFromInt(-40), decimal.NewFromInt(40))
+		require.NoError(t, err)
+
+		// Both transactions exist.
+		w, err := repo.GetByID(withdrawal.ID)
+		require.NoError(t, err)
+		assert.Equal(t, model.TransactionTypeWithdrawal, w.Type)
+		d, err := repo.GetByID(deposit.ID)
+		require.NoError(t, err)
+		assert.Equal(t, model.TransactionTypeDeposit, d.Type)
+
+		// Balances were applied.
+		accountRepo := NewAccountRepository(dbi.DB)
+		srcAfter, err := accountRepo.ByID(src.ID)
+		require.NoError(t, err)
+		assert.True(t, decimal.NewFromInt(-40).Equal(srcAfter.Balance))
+		dstAfter, err := accountRepo.ByID(dst.ID)
+		require.NoError(t, err)
+		assert.True(t, decimal.NewFromInt(40).Equal(dstAfter.Balance))
+
+		// Linked both ways via related_transactions.
+		other, err := repo.GetRelatedID(withdrawal.ID)
+		require.NoError(t, err)
+		require.NotNil(t, other)
+		assert.Equal(t, deposit.ID, *other)
+
+		other, err = repo.GetRelatedID(deposit.ID)
+		require.NoError(t, err)
+		require.NotNil(t, other)
+		assert.Equal(t, withdrawal.ID, *other)
+	})
+}
+
+func TestTransactionRepository_TransferIDsIn_ReturnsOnlyTransferHalves(t *testing.T) {
+	testutil.ForEachDB(t, func(t *testing.T, dbi testutil.DBInfo) {
+		repo := NewTransactionRepository(dbi.DB)
+
+		user := testutil.CreateTestUser(t, dbi.DB, "transferids@example.com", nil)
+		space := testutil.CreateTestSpace(t, dbi.DB, user.ID, "S")
+		src := testutil.CreateTestAccount(t, dbi.DB, space.ID, "Src")
+		dst := testutil.CreateTestAccount(t, dbi.DB, space.ID, "Dst")
+
+		// One transfer pair (source `w`, deposit `d`) plus one standalone txn.
+		now := time.Now()
+		w := &model.Transaction{ID: uuid.NewString(), Value: decimal.NewFromInt(5), Type: model.TransactionTypeWithdrawal, AccountID: src.ID, Title: "T-w", OccurredAt: now, CreatedAt: now, UpdatedAt: now}
+		d := &model.Transaction{ID: uuid.NewString(), Value: decimal.NewFromInt(5), Type: model.TransactionTypeDeposit, AccountID: dst.ID, Title: "T-d", OccurredAt: now, CreatedAt: now, UpdatedAt: now}
+		require.NoError(t, repo.TransferAtomic(w, d, decimal.NewFromInt(-5), decimal.NewFromInt(5)))
+		standalone := testutil.CreateTestTransaction(t, dbi.DB, src.ID, "solo", model.TransactionTypeDeposit, decimal.NewFromInt(1))
+
+		hits, err := repo.TransferIDsIn([]string{w.ID, d.ID, standalone.ID})
+		require.NoError(t, err)
+		assert.True(t, hits[w.ID], "withdrawal half should be flagged")
+		assert.True(t, hits[d.ID], "deposit half should be flagged")
+		assert.False(t, hits[standalone.ID], "standalone transaction should not be flagged")
+	})
+}
+
+func TestTransactionRepository_TransferIDsIn_EmptyInput(t *testing.T) {
+	testutil.ForEachDB(t, func(t *testing.T, dbi testutil.DBInfo) {
+		repo := NewTransactionRepository(dbi.DB)
+		hits, err := repo.TransferIDsIn(nil)
+		require.NoError(t, err)
+		assert.Empty(t, hits)
+	})
+}
+
+func TestTransactionRepository_GetRelatedID_NoneWhenStandalone(t *testing.T) {
+	testutil.ForEachDB(t, func(t *testing.T, dbi testutil.DBInfo) {
+		repo := NewTransactionRepository(dbi.DB)
+
+		user := testutil.CreateTestUser(t, dbi.DB, "standalone@example.com", nil)
+		space := testutil.CreateTestSpace(t, dbi.DB, user.ID, "S")
+		acct := testutil.CreateTestAccount(t, dbi.DB, space.ID, "A")
+		txn := testutil.CreateTestTransaction(t, dbi.DB, acct.ID, "x", model.TransactionTypeDeposit, decimal.NewFromInt(1))
+
+		other, err := repo.GetRelatedID(txn.ID)
+		require.NoError(t, err)
+		assert.Nil(t, other)
+	})
+}