phpunit: how to check anything changed at all - database

Question

I'm pretty new in Unit testing.
We made a test
It starts with a certain content of a database
then there can 2 things happen.
Amsterdam is overwritten with Amsterdam
or
Amsterdam stays Amsterdam.... (nothing happens)
What is the best way to verify what of both happened?

Answer 1

Normally, you would test each case, and you can use a Mock Object to remove the dependency on the database.
In this case, you would structure a test that recognizes that nothing changed in the DB record. The Mock object returns a state from the database indicating that nothing has changed. Your test would then check that the code that executes next, reported this condition, and therefore passes the test.
A second test would then be done where the Mock Object returns the state from the database where the item was changed, so then the code that should be executed does what it should, and passes your test.
Repeat the above tests for failing conditions, and you have your code covered.
class YourDBClass {
private $DBRef;
// Constructor Injection, pass the Database object here
public function __construct($DatabaseObject = NULL)
{
if(! is_null($DatabaseObject) )
{
if($DatabaseObject instanceof YourDBAccessClass)
{
$this->SetDBClass($DatabaseObject);
}
}
}
function SetDBClass(YourDBAccessClass $DatabaseObject)
{
$this->DBRef = $DatabaseObject
}
function GetResult($request) {
$DBR = $this->DBRef;
$result = $DBRef->DoSomething($request);
if ($result->success == false)
$result->error = $this->GetErrorCode($result->errorCode);
}
function GetErrorCode($errorCode) {
// do stuff
}
}
Test:
class YourDBClassTest extends PHPUnit_Framework_TestCase
{
// Simple test for GetErrorCode to work Properly
public function testGetErrorCode()
{
$TestClass = new YourDBClass();
$this->assertEquals('One', $TestClass->GetErrorCode(1)); // Assumes GetErrorCode returns a string
$this->assertEquals('Two', $TestClass->GetErrorCode(2));
}
// Could also use dataProvider to send different returnValues, and then check with Asserts.
public function testGetResultsNoChange()
{
// Create a mock for the YourDBAccessClass,
// only mock the GetResult() method.
$MockService = $this->getMock('YourDBAccessClass', array('GetResult'));
// Set up the expectation for the GetResult() method
$MockService->expects($this->any())
->method('GetResult')
->will($this->returnValue("NoChange"));
// Create Test Object - Pass our Mock as the service
$TestClass = new YourDBClass($MockService);
// Or
// $TestClass = new YourDBClass();
// $TestClass->SetDBClass($MockService);
// Test GetResults
$QueryString = 'Some String since we did not specify it to the Mock'; // Could be checked with the Mock functions
$this->assertEquals('NoChange', $TestClass->GetResults($QueryString));
}
// Could also use dataProvider to send different returnValues, and then check with Asserts.
public function testGetResultsChanged()
{
// Create a mock for the YourDBAccessClass,
// only mock the GetResult() method.
$MockService = $this->getMock('YourDBAccessClass', array('GetResult'));
// Set up the expectation for the GetResult() method
$MockService->expects($this->any())
->method('GetResult')
->will($this->returnValue("Amsterdam Changed"));
// Create Test Object - Pass our Mock as the service
$TestClass = new YourDBClass($MockService);
// Or
// $TestClass = new YourDBClass();
// $TestClass->SetDBClass($MockService);
// Test GetResults
$QueryString = 'Some String since we did not specify it to the Mock'; // Could be checked with the Mock functions
$this->assertEquals('Amsterdam Changed', $TestClass->GetResults($QueryString));
}
}

Answer 2

Steven, I discussed with my colleauges, They understand what you do.
but this is what we actually needed:
mysql UPDATE statement - overhead for same values?
I hope you follow. Nevertheless, thank you so much!