public function testAddFieldToFilter()
{
$field = 'title';
$value = 'test_filter';
$searchSql = 'sql query';
$this->connection->expects($this->any())->method('quoteIdentifier')->willReturn($searchSql);
$this->connection->expects($this->any())->method('prepareSqlCondition')->willReturn($searchSql);
$this->select->expects($this->once())->method('where')->with($searchSql, null, \Magento\Framework\DB\Select::TYPE_CONDITION);
$this->assertSame($this->collection, $this->collection->addFieldToFilter($field, $value));
}
