The document discusses the test data builder pattern for generating test data on demand instead of dropping and reloading a database, which is considered an anti-pattern. It introduces a user builder class that simplifies the construction of complex objects with sensible default values. The text emphasizes the benefits of abstracting data construction complexity and poses questions about implementing this pattern.

1. Test Data Builder
Pattern
Alan Parkinson
CEO, Hindsight Software
@alan_parkinson

2. Tests
Application
Under Test
Application
Database
Mobile App Server
Drop and reload the
database before
every test

3. Who has done this?

4. Database
reloading is an
Anti Pattern
Creating and maintaining SQL
scripts is error prone and time
consuming

5. Tests
Application
Under Test
Application
Database
Limitations of CI Scaling

6. Tests
Application
Under Test
Application
Database
What if we could generate
test data on demand?

7. Create test data on-
demand
with the Test Data
Builder Pattern

8. What is a Builder?
new UserBuilder()
an object that knows how to construct another
object
User user = .build();

9. the object is complex to
construct
public class UserBuilder {
uses sensible default values
}
public User build() {
return new User(name, password,
email);
}
private String name = ``charlie``;
private String password = ``password``;
private String email = ``charlie@behave.pro``;

10. Overriding sensible
defaults
new UserBuilder()user = .build();
.withName(``alan
``).withPassword(``secr
et``)

11. Overriding sensible defaults
public class UserBuilder {
}
public User build() {
return new User(name, password, email);
}
private String name = ``charlie``;
private String password = ``password``;
private String email = ``charlie@behave.pro``;
public UserBuilder withName(String name) {
this.name = name;
return this;
}

12. What about the Test
Data?
create remote data
instead of an object

13. public class UserBuilder {
}
public UserDesc build() {
/*
Create data using SQL / REST API / UI?
*/
return new UserDesc(createdUserId);
}
private String name = ``charlie``;
private String password = ``password``;
private String email = ``charlie@behave.pro``;
public UserBuilder withName(String name) {
this.name = name;
return this;
}

14. Don`t drop and reload
the database
Generate and construct
Test Data on-demand
Abstract data contruction
complexity with the
Builder Pattern

15. Questions?
Alan Parkinson
CEO, Hindsight Software
@alan_parkinson