AssertJ
@assertj.github.io
Fluent testing assertions for Java and the JVM
Pinned
AssertJ
@assertj.github.io
· Jan 24
Release v3.27.7 · assertj/assertj
🔒 Security
Core
Fix XXE vulnerability in isXmlEqualTo assertion (CVE-2026-24400)
See GHSA-rqfh-9r24-8c9r for details; many thanks to @wxt201 and @Song-Li for responsibly reporting it!
🚫 Deprec...
github.com
📢 AssertJ 3.27.7 has been released!
This fixes CVE-2026-24400 🔒
Happy assertions!
github.com/assertj/asse...
This fixes CVE-2026-24400 🔒
Happy assertions!
github.com/assertj/asse...
Reposted by AssertJ
When we started TestLens, we knew who we were building it for: teams that take their test suites seriously. So it means a lot that some of the most widely used testing projects in the JVM world now use TestLens on their own pull requests.
👉️ Read more: testlens.app/blog/2026/09...
#java #junit
👉️ Read more: testlens.app/blog/2026/09...
#java #junit
Leading Open Source Projects Trust TestLens
JUnit Framework, AssertJ, Apache Groovy, Apache Grails, and Spock Framework
are early adopters of TestLens.
testlens.app
September 16, 2026 at 1:56 PM
When we started TestLens, we knew who we were building it for: teams that take their test suites seriously. So it means a lot that some of the most widely used testing projects in the JVM world now use TestLens on their own pull requests.
👉️ Read more: testlens.app/blog/2026/09...
#java #junit
👉️ Read more: testlens.app/blog/2026/09...
#java #junit
Reposted by AssertJ
Our next #JCON2026 session is live: 'Better #Assertions with #AssertJ' with @timtebeek
Not all #testing libraries are equal. Sure they all run your tests, but what happens when they #fail? “Expected ‘true’, was ‘false’” won’t help you …
Grab your coffee and hit play: youtu.be/W7BhLNVHuqo
Not all #testing libraries are equal. Sure they all run your tests, but what happens when they #fail? “Expected ‘true’, was ‘false’” won’t help you …
Grab your coffee and hit play: youtu.be/W7BhLNVHuqo
youtu.be
https://youtu.be/W7BhLNVHuqo
youtu.be
August 10, 2026 at 5:35 PM
Our next #JCON2026 session is live: 'Better #Assertions with #AssertJ' with @timtebeek
Not all #testing libraries are equal. Sure they all run your tests, but what happens when they #fail? “Expected ‘true’, was ‘false’” won’t help you …
Grab your coffee and hit play: youtu.be/W7BhLNVHuqo
Not all #testing libraries are equal. Sure they all run your tests, but what happens when they #fail? “Expected ‘true’, was ‘false’” won’t help you …
Grab your coffee and hit play: youtu.be/W7BhLNVHuqo
Reposted by AssertJ
I had a blast at JUG Lucerne, with a small but engaging crowd whom I spent almost three hours with! 😍
What stuck with me the most:
• AssertJ should be renamed to AssertJoy
• They would love a hands-on follow-up with more advanced use cases
Many thanks again to @mcpringle.bsky.social for having me!
What stuck with me the most:
• AssertJ should be renamed to AssertJoy
• They would love a hands-on follow-up with more advanced use cases
Many thanks again to @mcpringle.bsky.social for having me!
No good weather today 🌧️ ☔ so why not join me in JUG Lucerne and find out what a handful of developers are doing to ship the next major version of AssertJ? 🧑💻
www.jug.ch/html/events/...
www.jug.ch/html/events/...
Java User Group Switzerland: Event "What's wrong with AssertJ?! - How a decade of technical debt is addressed in version 4.0"
AssertJ has been a player in Java testing for over a decade, providing an intuitive set of strongly typed assertions designed to maximize test readability. Since the launch of version 3.0, the library...
www.jug.ch
July 11, 2026 at 2:40 PM
I had a blast at JUG Lucerne, with a small but engaging crowd whom I spent almost three hours with! 😍
What stuck with me the most:
• AssertJ should be renamed to AssertJoy
• They would love a hands-on follow-up with more advanced use cases
Many thanks again to @mcpringle.bsky.social for having me!
What stuck with me the most:
• AssertJ should be renamed to AssertJoy
• They would love a hands-on follow-up with more advanced use cases
Many thanks again to @mcpringle.bsky.social for having me!
Reposted by AssertJ
No good weather today 🌧️ ☔ so why not join me in JUG Lucerne and find out what a handful of developers are doing to ship the next major version of AssertJ? 🧑💻
www.jug.ch/html/events/...
www.jug.ch/html/events/...
Java User Group Switzerland: Event "What's wrong with AssertJ?! - How a decade of technical debt is addressed in version 4.0"
AssertJ has been a player in Java testing for over a decade, providing an intuitive set of strongly typed assertions designed to maximize test readability. Since the launch of version 3.0, the library...
www.jug.ch
July 1, 2026 at 9:42 AM
No good weather today 🌧️ ☔ so why not join me in JUG Lucerne and find out what a handful of developers are doing to ship the next major version of AssertJ? 🧑💻
www.jug.ch/html/events/...
www.jug.ch/html/events/...
Reposted by AssertJ
Now the Java User Group in Zurich knows what's wrong with AssertJ! And also how we're working to improve things. We're still in the early stages, but I can't wait to see all this work shipped to our users 🚀
Thank you so much to everyone who joined and @patbaumgartner.com for hosting! I had a blast!
Thank you so much to everyone who joined and @patbaumgartner.com for hosting! I had a blast!
May 14, 2026 at 9:23 AM
Now the Java User Group in Zurich knows what's wrong with AssertJ! And also how we're working to improve things. We're still in the early stages, but I can't wait to see all this work shipped to our users 🚀
Thank you so much to everyone who joined and @patbaumgartner.com for hosting! I had a blast!
Thank you so much to everyone who joined and @patbaumgartner.com for hosting! I had a blast!
Reposted by AssertJ
Less than a week to go! 🚀
Join me this Tuesday at PH Zürich to discover how AssertJ 4 is about breaking things (carefully) to make your testing life better.
Come for the technical debt, stay for the drinks and networking! 🍻
www.jug.ch/html/events/...
Join me this Tuesday at PH Zürich to discover how AssertJ 4 is about breaking things (carefully) to make your testing life better.
Come for the technical debt, stay for the drinks and networking! 🍻
www.jug.ch/html/events/...
Java User Group Switzerland: Event "What's wrong with AssertJ?! - How a decade of technical debt is addressed in version 4.0"
AssertJ has been a player in Java testing for over a decade, providing an intuitive set of strongly typed assertions designed to maximize test readability. Since the launch of version 3.0, the library...
www.jug.ch
May 7, 2026 at 6:47 AM
Less than a week to go! 🚀
Join me this Tuesday at PH Zürich to discover how AssertJ 4 is about breaking things (carefully) to make your testing life better.
Come for the technical debt, stay for the drinks and networking! 🍻
www.jug.ch/html/events/...
Join me this Tuesday at PH Zürich to discover how AssertJ 4 is about breaking things (carefully) to make your testing life better.
Come for the technical debt, stay for the drinks and networking! 🍻
www.jug.ch/html/events/...
Reposted by AssertJ
Excited for #JCON EUROPE 2026? See Tim te Beek at #JCON2026 in Cologne talking about 'Better Assertions with #AssertJ'
Not all testing #libraries are equal. Sure they all run your #tests, but what happens when they fail? “Expected ‘true’, …
🎟️ 2026.europe.jcon.one/tickets
Free for #JUG members
Not all testing #libraries are equal. Sure they all run your #tests, but what happens when they fail? “Expected ‘true’, …
🎟️ 2026.europe.jcon.one/tickets
Free for #JUG members
February 19, 2026 at 8:00 AM
Reposted by AssertJ
📢 AssertJ joined the GitHub Secure Open Source Fund, a program that leveled up security across 67 open source projects.
What changed for us: SHA pinning, immutable releases, incident response plan, and a mindset shift toward security awareness 🔒
The impact? More robust JVM assertions 🚀
What changed for us: SHA pinning, immutable releases, incident response plan, and a mindset shift toward security awareness 🔒
The impact? More robust JVM assertions 🚀
February 17, 2026 at 8:17 PM
📢 AssertJ joined the GitHub Secure Open Source Fund, a program that leveled up security across 67 open source projects.
What changed for us: SHA pinning, immutable releases, incident response plan, and a mindset shift toward security awareness 🔒
The impact? More robust JVM assertions 🚀
What changed for us: SHA pinning, immutable releases, incident response plan, and a mindset shift toward security awareness 🔒
The impact? More robust JVM assertions 🚀
Reposted by AssertJ
#OpenRewrite v8.73.0 is out! 🍰
🐍 Python 2 parser + Python 3 recipes
🐳 Docker parser + recipes
🍂 Propagate Maven parent POM changes
🧪 New AssertJ and Mockito recipes
🔌 Apache HttpAsyncClient 4→5
🏛️ Struts 1→2→5→6→7 recipes
🧙 Dropwizard 5.0 migration
🐛 Tons of fixes
github.com/openrewrite/...
🐍 Python 2 parser + Python 3 recipes
🐳 Docker parser + recipes
🍂 Propagate Maven parent POM changes
🧪 New AssertJ and Mockito recipes
🔌 Apache HttpAsyncClient 4→5
🏛️ Struts 1→2→5→6→7 recipes
🧙 Dropwizard 5.0 migration
🐛 Tons of fixes
github.com/openrewrite/...
Release 3.24.0 · openrewrite/rewrite-recipe-bom
What's Changed
Incorporates the latest versions of OpenRewrite (v8.73.0), the rewrite-gradle-plugin (v7.26.0), and the rewrite-maven-plugin (v6.29.0) to improve code parsing accuracy and recipe ex...
github.com
February 11, 2026 at 5:04 PM
#OpenRewrite v8.73.0 is out! 🍰
🐍 Python 2 parser + Python 3 recipes
🐳 Docker parser + recipes
🍂 Propagate Maven parent POM changes
🧪 New AssertJ and Mockito recipes
🔌 Apache HttpAsyncClient 4→5
🏛️ Struts 1→2→5→6→7 recipes
🧙 Dropwizard 5.0 migration
🐛 Tons of fixes
github.com/openrewrite/...
🐍 Python 2 parser + Python 3 recipes
🐳 Docker parser + recipes
🍂 Propagate Maven parent POM changes
🧪 New AssertJ and Mockito recipes
🔌 Apache HttpAsyncClient 4→5
🏛️ Struts 1→2→5→6→7 recipes
🧙 Dropwizard 5.0 migration
🐛 Tons of fixes
github.com/openrewrite/...
📢 AssertJ 3.27.7 has been released!
This fixes CVE-2026-24400 🔒
Happy assertions!
github.com/assertj/asse...
This fixes CVE-2026-24400 🔒
Happy assertions!
github.com/assertj/asse...
Release v3.27.7 · assertj/assertj
🔒 Security
Core
Fix XXE vulnerability in isXmlEqualTo assertion (CVE-2026-24400)
See GHSA-rqfh-9r24-8c9r for details; many thanks to @wxt201 and @Song-Li for responsibly reporting it!
🚫 Deprec...
github.com
January 24, 2026 at 8:30 PM
📢 AssertJ 3.27.7 has been released!
This fixes CVE-2026-24400 🔒
Happy assertions!
github.com/assertj/asse...
This fixes CVE-2026-24400 🔒
Happy assertions!
github.com/assertj/asse...
Reposted by AssertJ
🚀 New update: AssertJ support in Testcontainers Mailpit
I just added AssertJ assertions to my Testcontainers Mailpit project.
You can now write fluent assertions instead of low-level checks.
🔗 GitHub: github.com/martinellich...
Feedback is welcome 👍
I just added AssertJ assertions to my Testcontainers Mailpit project.
You can now write fluent assertions instead of low-level checks.
🔗 GitHub: github.com/martinellich...
Feedback is welcome 👍
GitHub - martinellich/testcontainers-mailpit
Contribute to martinellich/testcontainers-mailpit development by creating an account on GitHub.
github.com
January 13, 2026 at 1:12 PM
🚀 New update: AssertJ support in Testcontainers Mailpit
I just added AssertJ assertions to my Testcontainers Mailpit project.
You can now write fluent assertions instead of low-level checks.
🔗 GitHub: github.com/martinellich...
Feedback is welcome 👍
I just added AssertJ assertions to my Testcontainers Mailpit project.
You can now write fluent assertions instead of low-level checks.
🔗 GitHub: github.com/martinellich...
Feedback is welcome 👍
Reposted by AssertJ
This video is still relevant: “AssertJ — Use It Now!” 🚀
If you write Java tests, this one’s for you. Learn how AssertJ can make your assertions cleaner, clearer, and more powerful.
Watch now: youtu.be/qn4AMKTPpg8
#Java #Testing #AssertJ #CleanCode #DevTips
If you write Java tests, this one’s for you. Learn how AssertJ can make your assertions cleaner, clearer, and more powerful.
Watch now: youtu.be/qn4AMKTPpg8
#Java #Testing #AssertJ #CleanCode #DevTips
AssertJ use it now
YouTube video by Mike Møller Nielsen
youtu.be
December 24, 2025 at 9:50 PM
This video is still relevant: “AssertJ — Use It Now!” 🚀
If you write Java tests, this one’s for you. Learn how AssertJ can make your assertions cleaner, clearer, and more powerful.
Watch now: youtu.be/qn4AMKTPpg8
#Java #Testing #AssertJ #CleanCode #DevTips
If you write Java tests, this one’s for you. Learn how AssertJ can make your assertions cleaner, clearer, and more powerful.
Watch now: youtu.be/qn4AMKTPpg8
#Java #Testing #AssertJ #CleanCode #DevTips
Reposted by AssertJ
🤔 Who said that AssertJ 3 is in maintenance mode?
📢 We're planning an exceptional 3.28 release – let us know what you'd like to see in there! 👇
github.com/orgs/assertj...
📢 We're planning an exceptional 3.28 release – let us know what you'd like to see in there! 👇
github.com/orgs/assertj...
Backport Scope for AssertJ 3.28.0 · assertj · Discussion #4018
We recently talked about how version 4 still needs a bit more work and probably won't be ready until at least the first half of 2026. Releasing a new major version is a rare opportunity for us: we ...
github.com
November 18, 2025 at 9:55 PM
🤔 Who said that AssertJ 3 is in maintenance mode?
📢 We're planning an exceptional 3.28 release – let us know what you'd like to see in there! 👇
github.com/orgs/assertj...
📢 We're planning an exceptional 3.28 release – let us know what you'd like to see in there! 👇
github.com/orgs/assertj...
Reposted by AssertJ
#OpenRewrite v8.68.1 is out! 🛬
🌱 Spring Boot 4.0: additional properties & dependencies
🍃 Migrate Spring Retry to Resilience
🧪 Hamcrest to AssertJ & JMockit to Mockito fixes
🟢 Node 22/24 upgrade recipes: fs, zlib, crypto & more
🤠 Jackson v3: migrate modules & feature flags
github.com/openrewrite/...
🌱 Spring Boot 4.0: additional properties & dependencies
🍃 Migrate Spring Retry to Resilience
🧪 Hamcrest to AssertJ & JMockit to Mockito fixes
🟢 Node 22/24 upgrade recipes: fs, zlib, crypto & more
🤠 Jackson v3: migrate modules & feature flags
github.com/openrewrite/...
Release 3.20.0 · openrewrite/rewrite-recipe-bom
What's Changed
Incorporates the latest versions of OpenRewrite (v8.68.1), the rewrite-gradle-plugin (v7.22.0), and the rewrite-maven-plugin (v6.25.0) to improve code parsing accuracy and recipe ex...
github.com
December 5, 2025 at 4:33 PM
#OpenRewrite v8.68.1 is out! 🛬
🌱 Spring Boot 4.0: additional properties & dependencies
🍃 Migrate Spring Retry to Resilience
🧪 Hamcrest to AssertJ & JMockit to Mockito fixes
🟢 Node 22/24 upgrade recipes: fs, zlib, crypto & more
🤠 Jackson v3: migrate modules & feature flags
github.com/openrewrite/...
🌱 Spring Boot 4.0: additional properties & dependencies
🍃 Migrate Spring Retry to Resilience
🧪 Hamcrest to AssertJ & JMockit to Mockito fixes
🟢 Node 22/24 upgrade recipes: fs, zlib, crypto & more
🤠 Jackson v3: migrate modules & feature flags
github.com/openrewrite/...
Reposted by AssertJ
Instead of buying more stuff that I don’t really need, I’m sponsoring open source #Java projects that I rely on, starting with #JUnit and #AssertJ (via core maintainers Joel and Stefano).
If I was a big company using Java, I’d be embarrassed at not sponsoring these projects.
If I was a big company using Java, I’d be embarrassed at not sponsoring these projects.
November 28, 2025 at 5:11 PM
Reposted by AssertJ
Many thanks to you, @mcpringle.bsky.social, and Alexandra, for the amazing organization! 🙏
So many new contributors to @assertj.github.io in a single day!
github.com/hack-commit-...
So many new contributors to @assertj.github.io in a single day!
github.com/hack-commit-...
Add AssertJ contributions by scordio · Pull Request #7 · hack-commit-push/switzerland2025
github.com
November 22, 2025 at 7:44 PM
Many thanks to you, @mcpringle.bsky.social, and Alexandra, for the amazing organization! 🙏
So many new contributors to @assertj.github.io in a single day!
github.com/hack-commit-...
So many new contributors to @assertj.github.io in a single day!
github.com/hack-commit-...
🤔 Who said that AssertJ 3 is in maintenance mode?
📢 We're planning an exceptional 3.28 release – let us know what you'd like to see in there! 👇
github.com/orgs/assertj...
📢 We're planning an exceptional 3.28 release – let us know what you'd like to see in there! 👇
github.com/orgs/assertj...
Backport Scope for AssertJ 3.28.0 · assertj · Discussion #4018
We recently talked about how version 4 still needs a bit more work and probably won't be ready until at least the first half of 2026. Releasing a new major version is a rare opportunity for us: we ...
github.com
November 18, 2025 at 9:55 PM
🤔 Who said that AssertJ 3 is in maintenance mode?
📢 We're planning an exceptional 3.28 release – let us know what you'd like to see in there! 👇
github.com/orgs/assertj...
📢 We're planning an exceptional 3.28 release – let us know what you'd like to see in there! 👇
github.com/orgs/assertj...
Reposted by AssertJ
Hack.Commit.Push Switzerland is just one week away! 🇨🇭
This is a great opportunity to get involved in Open Source projects like @assertj.github.io, with direct guidance from the maintainers!
This is a great opportunity to get involved in Open Source projects like @assertj.github.io, with direct guidance from the maintainers!
The next edition of Hack.Commit.Push Switzerland🇨🇭will take place in Rotkreuz LU this November 22nd. Care to join us for some Open Source hacking? It’s for a good cause!
switzerland2025.hack-commit-pu.sh
switzerland2025.hack-commit-pu.sh
hack-commit-push · One Day to Contribute to Open Source
switzerland2025.hack-commit-pu.sh
November 13, 2025 at 10:31 AM
Hack.Commit.Push Switzerland is just one week away! 🇨🇭
This is a great opportunity to get involved in Open Source projects like @assertj.github.io, with direct guidance from the maintainers!
This is a great opportunity to get involved in Open Source projects like @assertj.github.io, with direct guidance from the maintainers!
Reposted by AssertJ
Sur le blog de #norsys, mon collègue Kelean vient de publier un billet qui présente @assertj.github.io et comment le mettre à profit pour améliorer ses tests unitaires.
medium.com/norsys-octog...
#JUnit #AssertJ #Java #Test #TestUnitaire
medium.com/norsys-octog...
#JUnit #AssertJ #Java #Test #TestUnitaire
October 17, 2025 at 7:16 AM
Sur le blog de #norsys, mon collègue Kelean vient de publier un billet qui présente @assertj.github.io et comment le mettre à profit pour améliorer ses tests unitaires.
medium.com/norsys-octog...
#JUnit #AssertJ #Java #Test #TestUnitaire
medium.com/norsys-octog...
#JUnit #AssertJ #Java #Test #TestUnitaire
Reposted by AssertJ
Our next meetup will take place on November 4th at ING Leeuwarden to help you improve your testing with @timtebeek.github.io covering AssertJ and @simoneromani.bsky.social mutating tests for more confidence.
Sign up at www.meetup.com/jug-noord/ev... !
Sign up at www.meetup.com/jug-noord/ev... !
October 13, 2025 at 8:10 PM
Our next meetup will take place on November 4th at ING Leeuwarden to help you improve your testing with @timtebeek.github.io covering AssertJ and @simoneromani.bsky.social mutating tests for more confidence.
Sign up at www.meetup.com/jug-noord/ev... !
Sign up at www.meetup.com/jug-noord/ev... !
It's great to see the community actively watching over the early development of AssertJ 4!
🧪 Deep Dive Monday at #Jfokus - Break Your Testing Habits with Tim te Beek & Rick Ossendrijver
Unlearn the old, master the new - JUnit 6, AssertJ 4 & modern testing practices.
Forge your path in the halls of code ⚡
👉 www.jfokus.se
#DeveloperConference #Java #Testing #JUnit #AssertJ #CleanCode
Unlearn the old, master the new - JUnit 6, AssertJ 4 & modern testing practices.
Forge your path in the halls of code ⚡
👉 www.jfokus.se
#DeveloperConference #Java #Testing #JUnit #AssertJ #CleanCode
October 9, 2025 at 4:59 PM
It's great to see the community actively watching over the early development of AssertJ 4!
Reposted by AssertJ
btw, if you run a user group/meetup and want me to present any of my talks (on Testable Architecture, Event Sourcing, etc.) to your group (remotely or in person in the SF Bay Area), let me know!
See my Ted Talks page: ted.dev/talks
#Java #EventSourcing #JUnit #AssertJ
See my Ted Talks page: ted.dev/talks
#Java #EventSourcing #JUnit #AssertJ
My Presentations | Ted M. Young
Articles, Videos, Training, and Coaching for Java Developers
ted.dev
October 6, 2025 at 11:01 PM
btw, if you run a user group/meetup and want me to present any of my talks (on Testable Architecture, Event Sourcing, etc.) to your group (remotely or in person in the SF Bay Area), let me know!
See my Ted Talks page: ted.dev/talks
#Java #EventSourcing #JUnit #AssertJ
See my Ted Talks page: ted.dev/talks
#Java #EventSourcing #JUnit #AssertJ
📢 AssertJ 3.27.6 has been released!
This fixes a 🐛 regression related to the module descriptor 🧩
Happy assertions!
github.com/assertj/asse...
This fixes a 🐛 regression related to the module descriptor 🧩
Happy assertions!
github.com/assertj/asse...
Release v3.27.6 · assertj/assertj
🐛 Bug Fixes
Core
Add missing export for org.assertj.core.annotation #3951
❤️ Contributors
Thanks to all the contributors who worked on this release:
@duponter
github.com
September 22, 2025 at 7:26 PM
📢 AssertJ 3.27.6 has been released!
This fixes a 🐛 regression related to the module descriptor 🧩
Happy assertions!
github.com/assertj/asse...
This fixes a 🐛 regression related to the module descriptor 🧩
Happy assertions!
github.com/assertj/asse...