AssertJ

Learn about the AssetJ library, and how it helps us to write better unit tests.

AssertJ is a Java library used alongside JUnit 5 to write fluent assertions.

AssertJ contains feature-rich assertions and helpful error messages. This improves test code readability, and helps us debug failed unit tests.

Different modules of AssertJ

AssertJ is composed of several modules:

  • Core Module - This module provides assertions for JDK types (String, Iterable, Stream, Path, File, Map, etc.)

  • Guava: Provides assertions for types coming from the “Guava” library (Multimap, Optional, etc.).

  • Joda Time: This module provides assertions for Joda Time Types (DateTime, LocalDateTime).

  • Neo4J: Provides assertions for Neo4J types (Path, Node, Relationship).

  • DB: Provides assertions for relational database types (Table, Row, Column).

  • Swing: Provides an API for functional testing of Swing user interfaces.

Set up AssertJ using Maven

We use the following Maven coordinates to install the AssertJ library with Maven.

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