Test deleteOrphanedRevisions.php

Why:
* Maintenance scripts in core have a low percentage of test coverage
* Testing these scripts helps avoid regressions and bugs

What:
* Create DeleteOrphanedRevisionsTest which fully tests the
  maintenance script.

Bug: T371167
Change-Id: I759a9203c52fd00cdeb5effe38f01190dec1fc80

tests/phpunit/maintenance/DeleteOrphanedRevisionsTest.php

@@ -0,0 +1,73 @@
+<?php
+
+namespace MediaWiki\Tests\Maintenance;
+
+use DeleteOrphanedRevisions;
+use MediaWiki\Tests\Unit\Permissions\MockAuthorityTrait;
+use MediaWiki\Tests\User\TempUser\TempUserTestTrait;
+
+/**
+ * @covers \DeleteOrphanedRevisions
+ * @group Database
+ * @author Dreamy Jazz
+ */
+class DeleteOrphanedRevisionsTest extends MaintenanceBaseTestCase {
+
+	use TempUserTestTrait;
+	use MockAuthorityTrait;
+
+	protected function getMaintenanceClass() {
+		return DeleteOrphanedRevisions::class;
+	}
+
+	public function testExecuteForNoFoundRevisions() {
+		// Get revisions which are not orphaned, so that we know the script won't attempt to delete them.
+		$this->editPage( $this->getExistingTestPage(), 'testing1234' );
+		$this->maintenance->execute();
+		$this->expectOutputRegex( "/Checking for orphaned revisions.*found 0.\n$/" );
+	}
+
+	public function testExecuteForOrphanedRevisions() {
+		$this->disableAutoCreateTempUser();
+		$testTitle = $this->getExistingTestPage();
+		// Get revisions which are not orphaned, so that we know the script won't attempt to delete them.
+		$this->editPage( $testTitle, 'testing1234' );
+		// Get revisions which are orphaned, one which has rev_page as 0 and the other which has a rev_page but
+		// the page ID does not exist.
+		$firstOrphanedRevId = $this->editPage( $testTitle, 'testing123456' )->getNewRevision()->getId();
+		$secondOrphanedRevId = $this->editPage(
+			$testTitle, 'testing1234567', '', NS_MAIN, $this->mockAnonUltimateAuthority()
+		)->getNewRevision()->getId();
+		$this->getDb()->newUpdateQueryBuilder()
+			->update( 'revision' )
+			->set( [ 'rev_page' => 123456 ] )
+			->where( [ 'rev_id' => $secondOrphanedRevId ] )
+			->execute();
+		$this->getDb()->newUpdateQueryBuilder()
+			->update( 'revision' )
+			->set( [ 'rev_page' => 0 ] )
+			->where( [ 'rev_id' => $firstOrphanedRevId ] )
+			->execute();
+		// Check that a row exists for the second rev ID in ip_changes, as this is necessary for the assertion
+		// further down to check that the row was actually deleted.
+		$this->newSelectQueryBuilder()
+			->select( 'COUNT(*)' )
+			->from( 'ip_changes' )
+			->where( [ 'ipc_rev_id' => $secondOrphanedRevId ] )
+			->assertFieldValue( 1 );
+		// Run the maintenance script
+		$this->maintenance->execute();
+		// Check that the orphaned revisions were actually deleted.
+		$this->expectOutputRegex( "/Checking for orphaned revisions.*found 2.\nDeleting.*done/" );
+		$this->newSelectQueryBuilder()
+			->select( 'COUNT(*)' )
+			->from( 'revision' )
+			->where( [ 'rev_id' => [ $firstOrphanedRevId, $secondOrphanedRevId ] ] )
+			->assertFieldValue( 0 );
+		$this->newSelectQueryBuilder()
+			->select( 'COUNT(*)' )
+			->from( 'ip_changes' )
+			->where( [ 'ipc_rev_id' => $secondOrphanedRevId ] )
+			->assertFieldValue( 0 );
+	}
+}