A required class was missing while executing org.assertj:assertj-assertions-generator-maven-plugin:2.1.0:generate-assertions: org.junit.rules.TestRule

[akuma8]

I am facing this issue when migrating my application from JDK8 to JDK11.

[ERROR] Failed to execute goal org.assertj:assertj-assertions-generator-maven-plugin:2.1.0:generate-assertions (default) on project mws-inbound: Execution default of goal org.assertj:assertj-assertions-generator-maven-plugin:2.1.0:generate-assertions failed: A required class was missing while executing org.assertj:assertj-assertions-generator-maven-plugin:2.1.0:generate-assertions: org.junit.rules.TestRule
[ERROR] -----------------------------------------------------
[ERROR] realm =    plugin>org.assertj:assertj-assertions-generator-maven-plugin:2.1.0
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
[ERROR] urls[0] = file:/C:/Users/admin/.m2/repository/org/assertj/assertj-assertions-generator-maven-plugin/2.1.0/assertj-assertions-generator-maven-plugin-2.1.0.jar
[ERROR] urls[1] = file:/C:/Users/admin/.m2/repository/org/assertj/assertj-assertions-generator/2.1.0/assertj-assertions-generator-2.1.0.jar
[ERROR] urls[2] = file:/C:/Users/admin/.m2/repository/org/apache/commons/commons-lang3/3.5/commons-lang3-3.5.jar
[ERROR] urls[3] = file:/C:/Users/admin/.m2/repository/commons-cli/commons-cli/1.2/commons-cli-1.2.jar
[ERROR] urls[4] = file:/C:/Users/admin/.m2/repository/com/google/guava/guava/20.0/guava-20.0.jar
[ERROR] urls[5] = file:/C:/Users/admin/.m2/repository/ch/qos/logback/logback-classic/1.0.13/logback-classic-1.0.13.jar
[ERROR] urls[6] = file:/C:/Users/admin/.m2/repository/ch/qos/logback/logback-core/1.0.13/logback-core-1.0.13.jar
[ERROR] urls[7] = file:/C:/Users/admin/.m2/repository/org/assertj/assertj-core/2.9.1/assertj-core-2.9.1.jar
[ERROR] urls[8] = file:/C:/Users/admin/.m2/repository/commons-collections/commons-collections/3.2.1/commons-collections-3.2.1.jar
[ERROR] urls[9] = file:/C:/Users/admin/.m2/repository/commons-io/commons-io/2.5/commons-io-2.5.jar
[ERROR] urls[10] = file:/C:/Users/admin/.m2/repository/backport-util-concurrent/backport-util-concurrent/3.1/backport-util-concurrent-3.1.jar
[ERROR] urls[11] = file:/C:/Users/admin/.m2/repository/org/codehaus/plexus/plexus-interpolation/1.11/plexus-interpolation-1.11.jar
[ERROR] urls[12] = file:/C:/Users/admin/.m2/repository/org/codehaus/plexus/plexus-utils/1.5.15/plexus-utils-1.5.15.jar
[ERROR] Number of foreign imports: 1
[ERROR] import: Entry[import  from realm ClassRealm[maven.api, parent: null]]
[ERROR] 

Any idea?

[shaundsmith]

We've hit the same problem with assertj-assertions-generator-maven-plugin:2.2.0.

We found that a mvn clean test causes the assertions to be created correctly, but any subsequent mvn test will fail with the above issue.

We're using JDK11/Maven 3.6.0/JUnit 5 in our tech stack.
A workaround for our particular case is to add an explicit dependency on JUnit 4 in the plugin's declaration:

<plugin>
    <groupId>org.assertj</groupId>
    <artifactId>assertj-assertions-generator-maven-plugin</artifactId>
    <version>2.2.0</version>
    <executions>
        <execution>
            <goals>
                <goal>generate-assertions</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        ....
    </configuration>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13</version>
        </dependency>
    </dependencies>
</plugin>

[pkrajanand]

I run into the same error when running mvn -Dit.test='testClassName.testMethodNameWithSpaces' verify.

My running environment is

Picked up _JAVA_OPTIONS: -Duser.home=/home
Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)
Maven home: /usr/share/maven
Java version: 1.8.0_252, vendor: Azul Systems, Inc., runtime: /usr/lib/jvm/zulu-8-amd64/jre
Default locale: en_US, platform encoding: ANSI_X3.4-1968
OS name: "linux", version: "4.19.76-linuxkit", arch: "amd64", family: "unix"

Any suggestions?

Of course, I didn't get the same when I run the whole test suite through mvn clean install

[bedla]

This is very interesting class loader problem, so I have investigated it more deeply and created repo to reproduce https://github.com/bedla/maven-assertj-generator-test-error

There are two workarounds described.

First to add JUnit4 to plugin dependencies:

            <plugin>
                <groupId>org.assertj</groupId>
                <artifactId>assertj-assertions-generator-maven-plugin</artifactId>
                <version>2.2.0</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>generate-assertions</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <generateJUnitSoftAssertions>true</generateJUnitSoftAssertions>
                    <packages>
                        <param>cz.bedla.dto</param>
                    </packages>
                </configuration>
                <dependencies>
                    <dependency>
                        <groupId>junit</groupId>
                        <artifactId>junit</artifactId>
                        <version>4.12</version>
                    </dependency>
                </dependencies>
            </plugin>

And second to disable JUnit soft assertion generation:

            <plugin>
                <groupId>org.assertj</groupId>
                <artifactId>assertj-assertions-generator-maven-plugin</artifactId>
                <version>2.2.0</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>generate-assertions</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <generateJUnitSoftAssertions>false</generateJUnitSoftAssertions>
                    <packages>
                        <param>cz.bedla.dto</param>
                    </packages>
                </configuration>
            </plugin>