add unit test for truncate_on_update()

tests/Fixtures/inc/Engine/Media/AboveTheFold/Admin/Controller/truncateOnUpdate.php

@@ -0,0 +1,22 @@
+<?php
+
+return [
+	'testShouldDoNothingWhenVersionUnder3.16.1' => [
+		'config'     => [
+			'filter'       => true,
+			'new_version'  => '3.16.2',
+			'old_version'  => '3.16.1',
+			'not_completed' => 0,
+		],
+		'expected' => false,
+	],
+	'testShouldTruncateWhenVersion3.16.1AndHigher' => [
+		'config'     => [
+			'filter'       => true,
+			'new_version'  => '3.16.1',
+			'old_version'  => '3.15.0',
+			'not_completed' => 0,
+		],
+		'expected' => true,
+	],
+];

tests/Unit/inc/Engine/Media/AboveTheFold/Admin/Controller/truncateOnUpdate.php

@@ -0,0 +1,56 @@
+<?php
+declare(strict_types=1);
+
+namespace WP_Rocket\Tests\Unit\inc\Engine\Media\AboveTheFold\Admin\Controller;
+
+use Mockery;
+use WP_Rocket\Engine\Media\AboveTheFold\Context\Context;
+use WP_Rocket\Engine\Media\AboveTheFold\Database\Tables\AboveTheFold as ATFTable;
+use WP_Rocket\Engine\Media\AboveTheFold\Database\Queries\AboveTheFold as ATFQuery;
+use WP_Rocket\Engine\Media\AboveTheFold\Admin\Controller;
+use WP_Rocket\Tests\Unit\TestCase;
+
+/**
+ * Test class covering WP_Rocket\Engine\Media\AboveTheFold\Admin\Controller::truncate_atf
+ *
+ * @group ATF
+ */
+class TestTruncateOnUpdate extends TestCase {
+	private $controller;
+	private $query;
+	private $table;
+	private $context;
+
+	public function setUp(): void {
+		parent::setUp();
+
+		$this->query = $this->createMock( ATFQuery::class );
+		$this->table = $this->createMock( ATFTable::class );
+		$this->context = Mockery::mock( Context::class );
+		$this->controller = new Controller( $this->table, $this->query, $this->context );
+	}
+
+	/**
+	 * @dataProvider configTestData
+	 */
+	public function testShouldDoExpected( $config, $expected ) {
+		$this->context->shouldReceive( 'is_allowed' )
+			->atMost()
+			->once()
+			->andReturn( $config['filter'] );
+
+		if ( ! $expected ) {
+			$this->query->expects( $this->never() )
+				->method( 'get_not_completed_count' );
+		} else {
+			$this->query->expects( $this->once() )
+				->method( 'get_not_completed_count' )
+				->willReturn( $config['not_completed'] );
+
+			$this->table->expects( $this->once() )
+				->method( 'truncate_atf_table' );
+		}
+
+		$this->controller->truncate_on_update( $config['new_version'], $config['old_version'] );
+	}
+}