Setup a "Text" type property

$property = new DIProperty( 'Foo' );
$property->setPropertyTypeId( '_txt' );

// Using a dedicated property to created a DV
$dataValue = DataValueFactory::getInstance()->newDataValueByProperty(
    $property,
    'Some text'
);

$this->assertInstanceof(
    '\SMWStringValue',
    $dataValue
);

$this->assertEquals(
    'Some text',
    $dataValue->getDataItem()->getString()
);

Using the MockBuilder

$store = $this->getMockBuilder( '\SMW\Store' )
    ->disableOriginalConstructor()
    ->getMockForAbstractClass();

$store->expects( $this->at( 0 ) )
    ->method( 'getPropertyValues' )
    ->will( $this->returnValue( array(
        new DIWikiPage( 'SomePropertyOfTypeBlob', SMW_NS_PROPERTY ) ) ) );

$store->expects( $this->at( 1 ) )
    ->method( 'getPropertyValues' )
    ->with(
        $this->equalTo( new DIWikiPage( 'SomePropertyOfTypeBlob', SMW_NS_PROPERTY ) ),
        $this->anything(),
        $this->anything() )
    ->will( $this->returnValue( array(
        \SMWDIUri::doUnserialize( 'http://semantic-mediawiki.org/swivt/1.0#_txt' ) ) ) );

// Inject the store as a mock object due to DIProperty::findPropertyTypeID finding the
// type dynamically when called without explicit declaration
ApplicationFactory::getInstance()->registerObject( 'Store', $store );

// Create a DV from a string value instead of using a dedicated typed
// property (used by #set, #subobject since the user input is a string and not
// a typed object)
$dataValue = DataValueFactory::getInstance()->newDataValueByText(
    'SomePropertyOfTypeBlob',
    'Some text'
);

$this->assertInstanceof(
    '\SMWStringValue',
    $dataValue
);

$this->assertEquals(
    'Some text',
    $dataValue->getDataItem()->getString()
);

// Reset instance to avoid issues with tests that follow hereafter
ApplicationFactory::getInstance()->clear();