Clover Knowledge Base : Spring can't initialize beans with Clover

Symptoms

After enabling Clover, compilation succeeds, but Spring fails to create beans at a runtime with a similar error:

java.lang.IllegalStateException: Failed to load ApplicationContext
...
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'someBean': Autowiring of fields failed; 
...
nested exception is org.springframework.beans.factory.BeanCreationException: Unsatisfied dependency of type [interface com.some.SomeBean]: expected at least 1 matching bean

Application runs correctly if Clover is disabled.

Cause

This might be caused by a fact that implementation for com.some.SomeBean is being generated in your build process. For example:

 <plugin>
   <groupId>org.apache.maven.plugins</groupId>
   <artifactId>maven-antrun-plugin</artifactId>
   <executions>
     <execution>
       <phase>generate-sources</phase>
       <goals>
         <goal>run</goal>
       </goals>
       <configuration>
         <target>
          <copy file="${project.build.sourceDirectory}/com/some/SomeBeanImpl.java.gen." 
                tofile="${project.build.sourceDirectory}/com/some/SomeBeanImpl.java" overwrite="true" />
         </target>
       </configuration>
     </execution>
   </executions>
 </plugin>

In such case, when you run standard Clover instrumentation, such as:

mvn clean clover:setup test clover:clover clover:aggregate

Clover's code instrumentation (clover:setup) will occur before bean's code generation (as the 'generate-sources' phase will be triggered by the 'test' phase). Clover will also change source roots (e.g. from 'src/main/java' to 'target/clover/src-instrumented'). As a consequence, the SomeBeanImpl.java file will be written to an old source root and will not be compiled at all.

Resolution

Please verify if your build process contains any code/resource generation. If it does, make sure that Clover is initialized and sources are instrumented after all files are have already been generated. You can either do it in a command line:

mvn clean generate-sources clover:setup test

or you can bind the 'clover:setup' to a build phase which happens after the 'generate-sources' one, for example:

 <plugin>
   <groupId>com.atlassian.maven.plugins</groupId>
   <artifactId>clover-maven-plugin</artifactId> <!-- Before 4.1.1 it was called maven-clover2-plugin -->
   <executions>
     <execution>
       <phase>process-sources</phase>
       <goals>
         <goal>setup</goal>
       </goals>
     </execution>
   </executions>
 </plugin>