feat: preserve transaction source order

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## [Backend 0.9.0] - 2026-08-20
+
+### Added
+
+- Preserved source-array transaction positions and used them as stable tie-breakers for same-date history sorting.
+
 ## [Backend 0.8.3] - 2026-08-20
 
 ### Fixed

backend/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@family-budget/backend",
-  "version": "0.8.3",
+  "version": "0.9.0",
   "private": true,
   "scripts": {
     "dev": "tsx watch src/app.ts",

backend/src/db/migrate.ts

@@ -287,6 +287,15 @@ const migrations: { name: string; sql: string }[] = [
         ON portfolio_trades(account_id, concluded_at DESC);
     `,
   },
+  {
+    name: '009_transaction_source_position',
+    sql: `
+      ALTER TABLE transactions ADD COLUMN IF NOT EXISTS source_position BIGINT NOT NULL DEFAULT 0;
+      UPDATE transactions SET source_position = id WHERE source_position = 0;
+      CREATE INDEX IF NOT EXISTS ix_transactions_date_position
+        ON transactions(operation_at, source_position, id);
+    `,
+  },
 ];
 
 export async function runMigrations(): Promise<void> {

backend/src/services/import.ts

@@ -219,7 +219,7 @@ export async function importStatement(
     // Insert transactions
     const insertedIds: number[] = [];
 
-    for (const tx of data.transactions) {
+    for (const [sourcePosition, tx] of data.transactions.entries()) {
       const fp = computeFingerprint(data.statement.accountNumber, tx);
       const isCashbackCommissionImport =
         tx.amountSigned === 0 &&
@@ -235,11 +235,11 @@ export async function importStatement(
 
       const result = await client.query(
         `INSERT INTO transactions
-           (account_id, operation_id, operation_at, amount_signed, commission, description, direction, fingerprint, category_id, is_category_confirmed, import_id)
+           (account_id, operation_id, operation_at, amount_signed, commission, description, direction, fingerprint, category_id, is_category_confirmed, import_id, source_position)
-         VALUES ($1, COALESCE($2::uuid, gen_random_uuid()), $3, $4, $5, $6, $7, $8, $9, $10, $11)
+         VALUES ($1, COALESCE($2::uuid, gen_random_uuid()), $3, $4, $5, $6, $7, $8, $9, $10, $11, $12)
          ON CONFLICT DO NOTHING
          RETURNING id`,
-        [accountId, tx.operationId ?? null, tx.operationAt, tx.amountSigned, tx.commission, tx.description, dir, fp, categoryId, isCategoryConfirmed, importId],
+        [accountId, tx.operationId ?? null, tx.operationAt, tx.amountSigned, tx.commission, tx.description, dir, fp, categoryId, isCategoryConfirmed, importId, sourcePosition],
       );
 
       if (result.rows.length > 0) {

backend/src/services/transactions.ts

@@ -14,6 +14,9 @@ export async function getTransactions(
   const pageSize = [10, 50, 100].includes(params.pageSize ?? 50) ? (params.pageSize ?? 50) : 50;
   const sortBy = params.sortBy === 'amount' ? 't.amount_signed' : 't.operation_at';
   const sortOrder = params.sortOrder === 'asc' ? 'ASC' : 'DESC';
+  const orderBy = params.sortBy === 'amount'
+    ? `${sortBy} ${sortOrder}, t.operation_at DESC, t.source_position ASC, t.id DESC`
+    : `t.operation_at ${sortOrder}, t.source_position ${sortOrder === 'ASC' ? 'DESC' : 'ASC'}, t.id ${sortOrder === 'ASC' ? 'DESC' : 'ASC'}`;
 
   const conditions: string[] = [];
   const values: unknown[] = [];
@@ -84,7 +87,7 @@ export async function getTransactions(
      JOIN accounts a ON a.id = t.account_id
      LEFT JOIN categories c ON c.id = t.category_id
      ${where}
-     ORDER BY ${sortBy} ${sortOrder}
+     ORDER BY ${orderBy}
      LIMIT $${idx++} OFFSET $${idx++}`,
     [...values, pageSize, offset],
   );