Hamcrest - what version to use? 1.3 or 2

问题:

I am quite confused. Currently I am testing my spring application using

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-test</artifactId>
   <scope>test</scope>
</dependency>

I was happy as long as I wanted to match RegularExpressions. In hamcrest 1.3 you need to write your own matcher, which I did not like that much. I searched and found that hamcrest 2.0 has something build in, like:

assertThat(DateHelper.getActualDateForXML(), MatchesPattern.matchesPattern("\\d{4}+-\\d{2}-+\\d{2}+T\\d{2}+:\\d{2}+:\\d{2}+"));

I was happy, I added:

<dependency>
    <groupId>org.hamcrest</groupId>
    <artifactId>hamcrest-junit</artifactId>
    <version>2.0.0.0</version>
    <scope>test</scope>
</dependency>

And kicked out the 1.3 hamcrest dependencies from spring-boot-starter-test:

<exclusions>
    <exclusion>
       <groupId>org.hamcrest</groupId>
       <artifactId>hamcrest-library</artifactId>
    </exclusion>
    <exclusion>
       <groupId>org.hamcrest</groupId>
       <artifactId>hamcrest-core</artifactId>
    </exclusion>
</exclusions>

Now everything is still working as I expect it to work, but I do not feel really comfortable. Because I can just find people writing about 1.3 and can not really find the use of hamcrest-junit 2.0.

Can somebody explain me the connection between them? Because it seems that hamcrest-junit 2.0 has everything build in from hamcrest 1.3...

Thanks Ben

回答1:

Based on Hamcrest Github

• Hamcrest Github CHANGES.txt
• Decouple the evolution of Hamcrest and JUnit
• Is this still being maintained?

and JUnit Lambda (Junit 5)

• Minimize dependencies (especially third-party)

My take on it

• hamcrest-junit 2.0 (should be) is a fresh start with also the goal to decouple hamcrest from junit
• in the meantime Junit 5 project kicked off which reduces/removes third party dependencies

=> In this situation, I expect it is prudent for the hamcrest guys to wait for / coordinate with the JUnit 5 project before moving forward substantially.

As @heenenee mentioned, the hamcrest guys became busy with other stuff and so not much is happening with the project at this point.

To answer

Can somebody explain me the connection between them? Because it seems that hamcrest-junit 2.0 has everything build in from hamcrest 1.3

• hamcrest-junit 2.0 started but the guys behind it got busy soon after (and still are) with other projects, so the development stopped
• there might also be some uncertainties regarding JUnit 5 which may be an incentive to defer further hamcrest-junit 2.0 development until the JUnit 5 release (speculation)

... but I do not feel really comfortable. Because I can just find people writing about 1.3 and can not really find the use of hamcrest-junit 2.0.

At the moment, other than for your case there is not much incentive to move to hamcrest-junit 2.0. Once Junit 5 releases I expect that there will be more incentive to move forward again.

回答2:

Great answer by Ivo, which really should be getting more votes, but here's some added information. If you check Maven for information on the dependencies, Java Hamcrest 2.0.0.0 and Hamcrest JUnit 2.0.0.0, there are some usage links. At the time I write this, it's 74 and 68 respectively, and no major projects from a brief browsing.

回答3:

The Hamcrest project has just released 2.1, and they reworked the package structure after thorough consideration. Make sure you follow the upgrade procedure. The artifact java-hamcrest 2.0.0.0 is considered a failed attempt now.