Java Assertions

Open-source Java projects categorized as Assertions

Top 6 Java Assertion Projects

  • Karate

    Test Automation Made Simple

    Project mention: Cucumber Maintainer out of Job and future of the project is uncertain | | 2023-03-03

    This is why we need better tools which will give benefits for the added complexity. If you need to create both the feature files AND the code, it's just complexity with little benefits. But frameworks like or are hiding this complexity and remove the code layer entirely. Which, in my view, this is where you need to be in 2023, particularly for API testing.

  • AssertJ

    AssertJ is a library providing easy to use rich typed assertions

  • Onboard AI

    ChatGPT with full context of any GitHub repo. Onboard AI learns any GitHub repo in minutes and lets you chat with it to locate functionality, understand different parts, and generate new code. Use it for free at

  • zerocode

    A community-developed, free, opensource, automated testing framework for microservices APIs, Kafka(Data Streams) and Load testing. Zerocode Open Source enables you to create, change and maintain your automated test scenarios via simple JSON or YAML files. Visit documentation below:

  • Scott Test Reporter

    Never debug a test again: Detailed failure reports and hassle free assertions for Java tests - Power Asserts for Java

  • unlogged-sdk

    Unlogged SDK for recording code execution

    Project mention: Show HN: Unlogged (YC S22) – open-source record and replay for Java | | 2023-10-30

    Hello HN! Parth, and Shardul here. We have been building for the last 21 months. We started as a time travel debugger and pivoted to record and replay with assertions, mocking, and code coverage. You can save the replays in the form of a JSON and commit them to your git.

    Both Parth and I come from an e-commerce/payments background where production bugs meant heavy financial losses. Big billion days/Black Friday sales meant months of code freezes with low productivity. Before committing the code, we wanted to replay production traffic and know the breaking changes right away, like in sub-second. Kind of like unit+integration tests on steroids.

    So, we built an SDK that adds probes to the code in compile time. The SDK logs code execution, in detail.


    We also built an IDE plugin that keeps monitoring code changes, hot reloads these changes, replays the relevant methods, and alerts on failing replays. It also lets developers call Java methods directly, mock downstream methods in run time, highlight code coverage in real-time, and show performance numbers for methods with inlay hints. (right above each method)


    We are excited to launch the first version of our product that replays with assertions + mocking + code coverage reports right inside the IDE.

    Link to our IntelliJ plugin:

    Record and Replay Demo:

    Define Assertions on Replay:

    Track Code Coverage:

    Generate JUnit Test Cases:

    Mocking when replaying:



    1. Create a production logger

  • Deep Dive

    Fluent assertions library for Java (by jdlib)

NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020). The latest post mention was on 2023-10-30.

Java Assertions related posts


What are some of the best open-source Assertion projects in Java? This list will help you:

Project Stars
1 Karate 7,707
2 AssertJ 2,510
3 zerocode 829
4 Scott Test Reporter 136
5 unlogged-sdk 119
6 Deep Dive 7
The modern API for authentication & user identity.
The APIs are flexible and easy-to-use, supporting authentication, user identity, and complex enterprise features like SSO and SCIM provisioning.