diff --git a/app/code/Magento/SalesRule/Test/Unit/Model/CouponGeneratorTest.php b/app/code/Magento/SalesRule/Test/Unit/Model/CouponGeneratorTest.php
new file mode 100644
index 0000000000000..24ea8f2ab5efb
--- /dev/null
+++ b/app/code/Magento/SalesRule/Test/Unit/Model/CouponGeneratorTest.php
@@ -0,0 +1,74 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\SalesRule\Test\Unit\Model;
+
+use Magento\SalesRule\Api\Data\CouponGenerationSpecInterface;
+use Magento\SalesRule\Api\Data\CouponGenerationSpecInterfaceFactory;
+use Magento\SalesRule\Model\CouponGenerator;
+use Magento\SalesRule\Model\Service\CouponManagementService;
+
+/**
+ * @covers \Magento\SalesRule\Model\CouponGenerator
+ */
+class CouponGeneratorTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * Testable Object
+     *
+     * @var CouponGenerator
+     */
+    private $couponGenerator;
+
+    /**
+     * @var CouponManagementService|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $couponManagementServiceMock;
+
+    /**
+     * @var CouponGenerationSpecInterfaceFactory|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $generationSpecFactoryMock;
+
+    /**
+     * @var CouponGenerationSpecInterface|\PHPUnit_Framework_MockObject_MockObject
+     */
+    private $generationSpecMock;
+
+    /**
+     * Set Up
+     *
+     * @return void
+     */
+    protected function setUp()
+    {
+        $this->generationSpecFactoryMock = $this->getMockBuilder(CouponGenerationSpecInterfaceFactory::class)
+            ->disableOriginalConstructor()->setMethods(['create'])->getMock();
+        $this->couponManagementServiceMock = $this->createMock(CouponManagementService::class);
+        $this->generationSpecMock = $this->createMock(CouponGenerationSpecInterface::class);
+        $this->couponGenerator = new CouponGenerator(
+            $this->couponManagementServiceMock,
+            $this->generationSpecFactoryMock
+        );
+    }
+
+    /**
+     * Test beforeSave method
+     *
+     * @return void
+     */
+    public function testBeforeSave()
+    {
+        $expected = ['test'];
+        $this->generationSpecFactoryMock->expects($this->once())->method('create')
+            ->willReturn($this->generationSpecMock);
+        $this->couponManagementServiceMock->expects($this->once())->method('generate')
+            ->with($this->generationSpecMock)->willReturn($expected);
+        $actual = $this->couponGenerator->generateCodes([]);
+        self::assertEquals($expected, $actual);
+    }
+}