diff --git a/tests/Unit/EcommerceFinance/ShippingReplicaSynchronizerTest.php b/tests/Unit/EcommerceFinance/ShippingReplicaSynchronizerTest.php
new file mode 100644
index 00000000..b55584e2
--- /dev/null
+++ b/tests/Unit/EcommerceFinance/ShippingReplicaSynchronizerTest.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace Tests\Unit\EcommerceFinance;
+
+use Illuminate\Support\Facades\DB;
+use Modules\EcommerceFinance\Services\Jushuitan\ShippingReplicaSynchronizer;
+use Modules\EcommerceFinance\Services\UpstreamReadOnlyQuery;
+use Modules\EcommerceFinance\Services\UpstreamReadOnlyQueryFactory;
+use Tests\TestCase;
+
+class ShippingReplicaSynchronizerTest extends TestCase
+{
+    public function test_sync_removes_only_the_known_demo_source_ids(): void
+    {
+        $db = DB::connection('business_mirror');
+        $db->table('jst_oms_shipping')->insert([
+            ['source_id' => 9000001, 'sku_source_id' => 9000001],
+            ['source_id' => 9000006, 'sku_source_id' => 9000006],
+            ['source_id' => 9000007, 'sku_source_id' => 9000007],
+            ['source_id' => 999999999, 'sku_source_id' => 999999999],
+        ]);
+
+        $upstream = $this->createMock(UpstreamReadOnlyQuery::class);
+        $upstream->expects($this->once())->method('select')->willReturn([]);
+        $factory = $this->createMock(UpstreamReadOnlyQueryFactory::class);
+        $factory->expects($this->once())
+            ->method('forSource')
+            ->with('operations_replica')
+            ->willReturn($upstream);
+
+        $result = (new ShippingReplicaSynchronizer($factory))->sync();
+
+        $this->assertSame(['processed' => 0, 'autoship' => 0], $result);
+        $this->assertSame(
+            [9000007, 999999999],
+            $db->table('jst_oms_shipping')->orderBy('source_id')->pluck('source_id')->map(fn ($id) => (int) $id)->all(),
+        );
+    }
+}