patrykwozinski / dev-recruitment

In a PHP exists inheriting by extends keyword from one class. We can also inherit from many places by Trait.

• setUp() method called before every unit test in class, everytime after test tearDown() is called
• setUpBeforeClass() method called once before all tests in testing class, after all tests tearDownAfterClass() is called

A great place to use an anonymous class are Stubs and other test doubles where we are not interrested which object is returned. For example StubRepository which implements interface of concrete repository depending on provided parameters can create specific needed anonymous class.

• isset() checks if element exists and has value including: 0, empty string, false; return false when value is null
• empty() checks if element exists and is not empty and not zero value; return true for null, 0, false, empty strings etc
• array_key_exists() checks only if array has specific key

isset() and empty() are language constructions. array_key_exists() is a function.

Native language functions are written in a specific programming language and are definitely slower than language constructs that are written in the language in which the language itself was created. For PHP this is C.

Tools for static code analysis in PHP examples:

• PHPstan
• PHPMetrics

Thanks to them, you can find many errors that do not even require the launch of applications or tests. They detect problems in the code and indicate ways to improve them. Static code analysis tools also help in learning new languages.

Dummy, Fake, Stub, Spy, Mock. They are used to plug the implementation.

Yes, the quality of the tests is as important as the quality of the application. It is also worth putting a lot of effort into their proper preparation, because poor quality tests are expensive to maintain and cause many problems.

The best way is to throw an exception, because the user's search assumption is not really met. Another way is returning null value. Anwers like: empty user object, empty list, empty array or false are incorrect.

At the moment when the class is already concrete - it inherits from the abstract or implements the interface. This blocks unnecessary levels of inheritance and forces the composition.

NullObject pattern is a great tool to fight with ubiquitous nulls, NullPointerException and creating useless if statements.

Value Objects hides implementation of native language functions by using behaviors. They give a higher level of abstraction. Thanks to Value Objects, we are able to determine the specific level of natural language that we will use during application development.

One of the sets of principles related to OOP is GRASP - General Responsibility Assignment Software Principles, which consists of nine rules about how to design a code and answer the questions: where to put some responsibility, who to assign responsibility to, how to manage dependencies and many more.

Design patterns are divided into three types:

• creational patterns
• structural patterns
• behavioral patterns

Command-Query Responsibility Segregation is a separation of the model into read model and write model. Using CQRS we create Commands and Queries. Command is never returns anything and query only ask for something - it never modifies data.

⚠️ Missing answer. Create a pull request and become a contributor!

Behavior of an object is a thing possible to the living creature. For example document->reassign(owner) - we can reassign new owner of a document. Getting and setting this information is not a behavior.

Adding prefixes such as get or set blocks us from being able to read the responsibility of classes and their characteristics. Getters and setters are procedural approach and are an incorrect habit that results in too much information being sent out of the class. Public methods should describe available interactions with an object and present his features.