Should you unit test Data Access Layer?

Should you unit test Data Access Layer?

Unit testing the DAL is worth it as mentioned if there is logic in there, for example if using the same StoredProc for insert & update its worth knowing that an insert works, a subsequent call updates the previous and a select returns it and not a list.

Does unit test interact with database?

You’re unit testing your code that interacts with the database, not the database itself, so think in terms of how to test those functions. If it’s possible for a field to be NULL , you should have a test that makes sure that your code handles NULL values correctly.

How do you write unit test cases for DAO layer?

2. Writing DAO Layer Unit Tests

1. Load the test specified configuration file before starting the test.
2. Once the configuration file is loaded, dependencies can be easily injected.
3. Restore the database state with @Rollback(true) annotation.
4. Each test should create some data and validate it.

What is unit testing in database?

April 8, 2019 by Esat Erkec. SQL unit testing is a testing method which allows us to test the smallest, atomic programmable part of a database object. SQL unit testing plays a key role in the modern database development cycle because it allows us to test individual parts of the database objects work as expected.

What is DbUnit?

DbUnit is a JUnit extension (also usable with Ant) targeted at database-driven projects that, among other things, puts your database into a known state between test runs. DbUnit has the ability to export and import your database data to and from XML datasets.

How do you write a JUnit test case for a database query?

1 Answer

1. Chose a proper set of parameter values.
2. (Optionally) Initialize the tested component in a required initial state.
3. Invoke the tested method.
4. Check that the returned result is equal to the expected result.
5. Clean up the tested component not to let any “dirt” from the executed test.

How do I do unit tests for methods that insert into a database?

4 Answers

1. Make the Repository a property on your unit of work.
2. Don’t create the Unit of Work directly, use a factory for that.
3. Make the factory a dependency of your class.
4. In your test pass a mock of the factory to the class you are testing that returns a mock of the Unit Of Work.

How do you write JUnit test cases for CRUD operations?

I will be using JUnit 5 (JUnit Jupiter) in a Spring Boot project with Spring Data JPA, Hibernate and MySQL database.

1. Annotations for Unit Testing Spring Data JPA.
2. Required Dependencies.
3. Code Entity Class.
4. Code Repository Interface.
5. Configure database connection properties.
6. Code Tests for CRUD operations.

What is spring boot Mockito?

Mockito is a mocking framework for unit tests written in Java. It is an open source framework available at github. You can use Mockito with JUnit to create and use mock objects during unit testing. To start using Mockito, download the JAR file and place it in your project class.

How do you test a unit test database?

How to unit test your database

1. Write a script that will wipe out the database before you start unit tests, then populate the database with a predefined set of data and run the tests.
2. Ensure that the database is in a known state before each test runs, and verify the state after the run using assertions logic.

How is unit testing done?

A typical unit test contains 3 phases: First, it initializes a small piece of an application it wants to test (also known as the system under test, or SUT), then it applies some stimulus to the system under test (usually by calling a method on it), and finally, it observes the resulting behavior.

What does the database layer do in unit testing?

This layer’s job is to connect the code to the database. It has to encapsulate the knowledge about db connection and syntax. In usually maps the domain language to database language. I look at this part of the unit tests as integration test, and as such I test that the database schema is equivalent against real or test database.

What is the best database for unit testing?

IM (in-memory) database is good option because it does not leave any trace back and you are sure that you will get empty tables before each test (generally a good practice). A good unit test should leave the database state same as it was before test case execution.

Why are unit test frameworks important?

For many business needs, they may end up modifying the UI layer, service layer while making minimal changes to the database. This increases the importance of using the Unit Test Frameworks to help identify and resolve issues at an early stage of development.

How to unit test Dao layer in spring?

How you should unit test DAO layer 1 Always create unit test specific configuration file This may be the first step for creating unit tests for your DAO layer. 2 Writing unit tests for DAO layer The next part comes writing junit (or any other framework) testcases. I am using spring-test module. 3 Package Structure