|
|
Die Kopplung von Datenzugriff und dem Domain Modell benötigt oft die Verwendung einer Datenbank für Testzwecke. Aber die Datenbank ist persistent über alle Tests was dazu führen kann das die Test Resultate sich gegenseitig beeinflussen. Weiters ist das Setup der Datenbank eine ganz schöne Arbeit damit die Tests laufen können. PHPUnit's Datenbank Extension vereinfacht das Testen mit einer Datenbank durch das Anbieten eines einfachen Mechanismus für das Setup und Herunterfahren der Datenbank zwischen den unterschiedlichen Tests. Diese Komponente erweitert die PHPUnit Datenbank Extension mit Zend Framework spezifischem Code, damit das Schreiben von Datenbank Tests für Zend Framework Anwendungen vereinfacht wird.
Das Testen von Datenbanken kann mit zwei konzeptionellen Einträgen beschrieben werden,
DataSets und DataTables. Intern kann die PHPUnit Datenbank Extension eine Objekt Struktur
von einer Datenbank erstellen, und dessen Tabellen und enthaltene Zeilen von einer
Konfigurationsdatei oder einer realen Datenbankinhalt. Dieser abstrakte Objektgraph kann
dann verglichen werden indem Assertions verwendet werden. Ein üblicher Verwendungszweck
beim Testen von Datenbanken ist das Setup von einigen Tabellen mit eingefügten Daten, in
denen dann einige Operationen stattfinden, und letztendlich geprüft wird das der
endgültige Datenbankstatus identisch mit dem vordefinierten und erwarteten Status ist.
Zend_Test_PHPUnit_Db vereinfacht diese Aufgabe indem es erlaubt wird
DataSets und DataTables von existierenden Zend_Db_Table_Abstract
oder Zend_Db_Table_Rowset_Abstract Instanzen erstellt werden.
Weiters erlaubt es diese Komponente jede Zend_Db_Adapter_Abstract
für das Testen zu integrieren wobei die originale Erweiterung nur mit
PDO arbeitet. Eine Implementation des Test Adapters für
Zend_Db_Adapter_Abstract ist auch in dieser Komponente inkludiert.
Sie erlaubt es einen Db Adapter zu instanziieren der überhaupt keine Datenbank benötigt und
als SQL arbeitet sowie als Ergebnis Stack der von den
API Methoden verwendet wird.
We are now writting some database tests for the Bug Database example in the
Zend_Db_Table documentation. First we begin to test that
inserting a new bug is actually saved in the database correctly. First we have to
setup a test-class that extends
Zend_Test_PHPUnit_DatabaseTestCase. This class extends the
PHPUnit Database Extension, which in turn extends the basic
PHPUnit_Framework_TestCase. A database testcase contains two
abstract methods that have to be implemented, one for the database connection and
one for the initial dataset that should be used as seed or fixture.
Note:
You should be familiar with the PHPUnit Database extension to follow this quickstart easily. Although all the concepts are explained in this documentation it may be helpful to read the PHPUnit documentation first.
class BugsTest extends Zend_Test_PHPUnit_DatabaseTestCase
{
private $_connectionMock;
/**
* Returns the test database connection.
*
* @return PHPUnit_Extensions_Database_DB_IDatabaseConnection
*/
protected function getConnection()
{
if($this->_connectionMock == null) {
$connection = Zend_Db::factory(...);
$this->_connectionMock = $this->createZendDbConnection(
$connection, 'zfunittests'
);
Zend_Db_Table_Abstract::setDefaultAdapter($connection);
}
return $this->_connectionMock;
}
/**
* @return PHPUnit_Extensions_Database_DataSet_IDataSet
*/
protected function getDataSet()
{
return $this->createFlatXmlDataSet(
dirname(__FILE__) . '/_files/bugsSeed.xml'
);
}
}
Here we create the database connection and seed some data into the database. Some important details should be noted on this code:
You cannot directly return a Zend_Db_Adapter_Abstract
from the getConnection() method, but a PHPUnit
specific wrapper which is generated with the
createZendDbConnection() method.
The database schema (tables and database) is not re-created on every testrun. The database and tables have to be created manually before running the tests.
Database tests by default truncate the data during setUp() and then insert the seed data which is returned from the getDataSet() method.
DataSets have to implement the interface
PHPUnit_Extensions_Database_DataSet_IDataSet.
There is a wide range of XML and YAML configuration file types included in
PHPUnit which allows to specifiy how the tables and datasets should look
like and you should look into the PHPUnit documentation to get the latest
information on these dataset specifications.
In the previous setup for the database testcase we have specified a seed file for the database fixture. We now create this file specified in the Flat XML format:
We will work with this four entries in the database table "zfbugs" in the next examples. The required MySQL schema for this example is:
CREATE TABLE IF NOT EXISTS `zfbugs` (
`bug_id` int(11) NOT NULL auto_increment,
`bug_description` varchar(100) default NULL,
`bug_status` varchar(20) default NULL,
`created_on` datetime default NULL,
`updated_on` datetime default NULL,
`reported_by` varchar(100) default NULL,
`assigned_to` varchar(100) default NULL,
`verified_by` varchar(100) default NULL,
PRIMARY KEY (`bug_id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 ;
Now that we have implemented the two required abstract methods of the
Zend_Test_PHPUnit_DatabaseTestCase and specified the seed
database content, which will be re-created for each new test, we can go about to make
our first assertion. This will be a test to insert a new bug.
class BugsTest extends Zend_Test_PHPUnit_DatabaseTestCase
{
public function testBugInsertedIntoDatabase()
{
$bugsTable = new Bugs();
$data = array(
'created_on' => '2007-03-22 00:00:00',
'updated_on' => '2007-03-22 00:00:00',
'bug_description' => 'Something wrong',
'bug_status' => 'NEW',
'reported_by' => 'garfield',
'verified_by' => 'garfield',
'assigned_to' => 'mmouse',
);
$bugsTable->insert($data);
$ds = new Zend_Test_PHPUnit_Db_DataSet_QueryDataSet(
$this->getConnection()
);
$ds->addTable('zfbugs', 'SELECT * FROM zfbugs');
$this->assertDataSetsEqual(
$this->createFlatXmlDataSet(dirname(__FILE__)
. "/_files/bugsInsertIntoAssertion.xml"),
$ds
);
}
}
Now up to the $bugsTable->insert($data); everything looks
familiar. The lines after that contain the assertion methodname. We want to verify
that after inserting the new bug the database has been updated correctly with the
given data. For this we create a
Zend_Test_PHPUnit_Db_DataSet_QueryDataSet instance and give
it a database connection. We will then tell this dataset that it contains a table
"zfbugs" which is given by an SQL statement. This current/actual state of the
database is compared to the expected database state which is contained in another
XML file "bugsInsertIntoAssertions.xml". This XML file is a slight deviation from
the one given above and contains another row with the expected data:
There are other ways to assert that the current database state equals an expected state. The "Bugs" table in the example already nows a lot about its inner state, so why not use this to our advantage? The next example will assert that deleting from the database is possible:
class BugsTest extends Zend_Test_PHPUnit_DatabaseTestCase
{
public function testBugDelete()
{
$bugsTable = new Bugs();
$bugsTable->delete(
$bugsTable->getAdapter()->quoteInto("bug_id = ?", 4)
);
$ds = new Zend_Test_PHPUnit_Db_DataSet_DbTableDataSet();
$ds->addTable($bugsTable);
$this->assertDataSetsEqual(
$this->createFlatXmlDataSet(dirname(__FILE__)
. "/_files/bugsDeleteAssertion.xml"),
$ds
);
}
}
We have created a Zend_Test_PHPUnit_Db_DataSet_DbTableDataSet
dataset here, which takes any Zend_Db_Table_Abstract instance
and adds it to the dataset with its table name, in this example "zfbugs". You could
add several tables more if you wanted using the method
addTable() if you want to check for expected database state
in more than one table.
Here we only have one table and check against an expected database state in "bugsDeleteAssertion.xml" which is the original seed dataset without the row with id 4.
Since we have only checked that two specific tables (not datasets) are equal in the previous examples we should also look at how to assert that two tables are equal. Therefore we will add another test to our TestCase which verifies updating behaviour of a dataset.
class BugsTest extends Zend_Test_PHPUnit_DatabaseTestCase
{
public function testBugUpdate()
{
$bugsTable = new Bugs();
$data = array(
'updated_on' => '2007-05-23',
'bug_status' => 'FIXED'
);
$where = $bugsTable->getAdapter()->quoteInto('bug_id = ?', 1);
$bugsTable->update($data, $where);
$rowset = $bugsTable->fetchAll();
$ds = new Zend_Test_PHPUnit_Db_DataSet_DbRowset($rowset);
$assertion = $this->createFlatXmlDataSet(
dirname(__FILE__) . '/_files/bugsUpdateAssertion.xml'
);
$expectedRowsets = $assertion->getTable('zfbugs');
$this->assertTablesEqual(
$expectedRowsets, $ds
);
}
}
Here we create the current database state from a
Zend_Db_Table_Rowset_Abstract instance in conjunction with
the Zend_Test_PHPUnit_Db_DataSet_DbRowset($rowset) instance
which creates an internal data-representation of the rowset. This can again be
compared against another data-table by using the
$this->assertTablesEqual() assertion.
The Quickstart already gave a good introduction on how database testing can be done using
PHPUnit and the Zend Framework. This section gives an overview over the API that the
Zend_Test_PHPUnit_Db component comes with and how it works
internally.
Note: Some Remarks on Database Testing
Just as the Controller TestCase is testing an application at an integration level, the Database TestCase is an integration testing method. Its using several different application layers for testing purposes and therefore should be consumed with caution.
It should be noted that testing domain and business logic with integration tests such as Zend Framework's Controller and Database TestCases is a bad practice. The purpose of an Integration test is to check that several parts of an application work smoothly when wired together. These integration tests do not replace the need for a set of unit tests that test the domain and business logic at a much smaller level, the isolated class.
The Zend_Test_PHPUnit_DatabaseTestCase class derives from the
PHPUnit_Extensions_Database_TestCase which allows to setup tests
with a fresh database fixture on each run easily. The Zend implementation offers some
additional convenience features over the PHPUnit Database extension when it comes to
using Zend_Db resources inside your tests. The workflow of a
database test-case can be described as follows.
For each test PHPUnit creates a new instance of the TestCase and calls the setUp() method.
The Database TestCase creates an instance of a Database Tester which handles the setting up and tearing down of the database.
The database tester collects the information on the database connection and initial dataset from getConnection() and getDataSet() which are both abstract methods and have to be implemented by any Database Testcase.
By default the database tester truncates the tables specified in the given dataset, and then inserts the data given as initial fixture.
When the database tester has finished setting up the database, PHPUnit runs the test.
After running the test, tearDown() is called. Because the database is wiped in setUp() before inserting the required initial fixture, no actions are executed by the database tester at this stage.
Note:
The Database TestCase expects the database schema and tables to be setup correctly to run the tests. There is no mechanism to create and tear down database tables.
The Zend_Test_PHPUnit_DatabaseTestCase class has some convenience
functions that can help writing tests that interact with the database and the database
testing extension.
The next table lists only the new methods compared to the
PHPUnit_Extensions_Database_TestCase, whose » API is documented in
the PHPUnit Documentation.
| Method | Description |
|---|---|
| createZendDbConnection(Zend_Db_Adapter_Abstract $connection, $schema) |
Create a PHPUnit Database Extension compatible Connection instance from
a Zend_Db_Adapter_Abstract instance. This method
should be used in for testcase setup when implementing the abstract
getConnection() method of the database testcase.
|
| getAdapter() |
Convenience method to access the underlying
Zend_Db_Adapter_Abstract instance which is nested
inside the PHPUnit database connection created with
getConnection().
|
| createDbRowset(Zend_Db_Table_Rowset_Abstract $rowset, $tableName = null) |
Create a DataTable Object that is filled with the data from a given
Zend_Db_Table_Rowset_Abstract instance. The table
the rowset is connected to is chosen when $tableName is
null.
|
| createDbTable(Zend_Db_Table_Abstract $table, $where = null, $order = null, $count = null, $offset = null) |
Create a DataTable object that represents the data contained in a
Zend_Db_Table_Abstract instance. For retrieving
the data fetchAll() is used, where the optional
parameters can be used to restrict the data table to a certain subset.
|
| createDbTableDataSet(array $tables=array()) |
Create a DataSet containing the given $tables, an array of
Zend_Db_Table_Abstract instances.
|
Because PHP does not support multiple inheritance it is not possible to use the
Controller and Database testcases in conjunction. However you can use the
Zend_Test_PHPUnit_Db_SimpleTester database tester in your
controller test-case to setup a database enviroment fixture for each new controller
test. The Database TestCase in general is only a set of convenience functions which can
also be accessed and used without the test case.
Example #1 Database integration example
This example extends the User Controller Test from the
Zend_Test_PHPUnit_ControllerTestCase documentation to include
a database setup.
class UserControllerTest extends Zend_Test_PHPUnit_ControllerTestCase
{
public function setUp()
{
$this->setupDatabase();
$this->bootstrap = array($this, 'appBootstrap');
parent::setUp();
}
public function setupDatabase()
{
$db = Zend_Db::factory(...);
$connection = Zend_Test_PHPUnit_Db_Connection($db,
'database_schema_name');
$databaseTester = new Zend_Test_PHPUnit_Db_SimpleTester($connection);
$databaseFixture =
new PHPUnit_Extensions_Database_DataSet_FlatXmlDataSet(
dirname(__FILE__) . '/_files/initialUserFixture.xml'
);
$databaseTester->setupDatabase($databaseFixture);
}
}
Now the Flat XML dataset "initialUserFixture.xml" is used to set the database into an initial state before each test, exactly as the DatabaseTestCase works internally.
There are times when you don't want to test parts of your application with a real database,
but are forced to because of coupling. The Zend_Test_DbAdapter offers
a convenient way to use a implementation of Zend_Db_Adapter_Abstract
without having to open a database connection. Furthermore this Adapter is very easy to mock
from within your PHPUnit testsuite, since it requires no constructor arguments.
The Test Adapter acts as a stack for various database results. Its order of results have to be userland implemented, which might be a tedious task for tests that call many different database queries, but its just the right helper for tests where only a handful of queries are executed and you know the exact order of the results that have to be returned to your userland code.
$adapter = new Zend_Test_DbAdapter();
$stmt1Rows = array(array('foo' => 'bar'), array('foo' => 'baz'));
$stmt1 = Zend_Test_DbStatement::createSelectStatement($stmt1Rows);
$adapter->appendStatementToStack($stmt1);
$stmt2Rows = array(array('foo' => 'bar'), array('foo' => 'baz'));
$stmt2 = Zend_Test_DbStatement::createSelectStatement($stmt2Rows);
$adapter->appendStatementToStack($stmt2);
$rs = $adapter->query('SELECT ...'); // Returns Statement 2
while ($row = $rs->fetch()) {
echo $rs['foo']; // Prints "Bar", "Baz"
}
$rs = $adapter->query('SELECT ...'); // Returns Statement 1
Behaviour of any real database adapter is simulated as much as possible such that methods like fetchAll(), fetchObject(), fetchColumn and more are working for the test adapter.
You can also put INSERT, UPDATE and DELETE statement onto the result stack, these however only return a statement which allows to specifiy the result of $stmt->rowCount().
$adapter = new Zend_Test_DbAdapter();
$adapter->appendStatementToStack(
Zend_Test_DbStatement::createInsertStatement(1)
);
$adapter->appendStatementToStack(
Zend_Test_DbStatement::createUpdateStatement(2)
);
$adapter->appendStatementToStack(
Zend_Test_DbStatement::createDeleteStatement(10)
);
The test adapter never checks if the query specified is really of the type SELECT, DELETE, INSERT or UPDATE which is returned next from the stack. The correct order of returning the data has to be implemented by the user of the test adapter.
The Test adapter also specifies methods to simulate the use of the methods listTables(), describeTables() and lastInsertId().
|
|
Copyright © 2005-2011 Zend Technologies Inc (compiled by mikaelkael with ZFDocumentor - SVN 18616).

