Page Comparison

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Unit tests
It tests the classes or methods directly, generally by using specific test framework (Junit, testNG, etc ...)
The "container framework" used behind the scene (Spring/ JBoss/ EJB or whatever) SHOULD NOT be used in the Unit test scope.
External calls to test servers or third party components/anything MUST NOT be done here. These type of tests should be executable by anybody locally in an IDE.
Due to that, it's sometimes required to make use of mock frameworks to replace the code that can't be triggered because it does require unreachable components
The mocking SHOULD NEVER consume the developer's bandwidth, that means mocking the code should be straight-forward.
Don't waste your time into a complicated implementation, for that there is a second test phase called "integration tests"

Also DO NOT add "isTest" flag in your code to replace the mock, this is a common test anti pattern that lead the useless tests.
Integration tests
It tests the code within the "container framework" and can make use of 3rd party components, like databases.
The 3rd party components could be emulated, or even better, could be physically mounted locally, with the help of docker for instance.
The starting of the those 3rd party components can be initiated/shut-downed by the build itself in a "Pre-integration/Post-integration" phase.

Here are some tips to setup that coverage per packager and per language

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Java

For java there are different plugins that must be included in the pom.xml,

This one is used to execute the unit tests, various config are available depending of the project need (https://maven.apache.org/surefire/maven-surefire-plugin/index.html)

<plugin>

  <groupId>org.apache.maven.plugins</groupId>

  <artifactId>maven-surefire-plugin</artifactId>

  <version>X.XX.X</version>

  <configuration>

   <forkCount>1</forkCount>

   <reuseForks>true</reuseForks>

   <useSystemClassLoader>false</useSystemClassLoader>

  </configuration>

</plugin>

This one is used to execute the integration tests, various config are available depending of the project need (https://maven.apache.org/surefire/maven-failsafe-plugin/index.html)

<plugin>

    <groupId>org.apache.maven.plugins</groupId>

    <artifactId>maven-failsafe-plugin</artifactId>

    <version>X.XX.X</version>

    <executions>

      <execution>

         <id>integration-tests</id>

         <goals>

           <goal>integration-test</goal>

           <goal>verify</goal>

         </goals>

         <configuration>

           <additionalClasspathElements>

              <additionalClasspathElement>${project.build.directory}/classes</additionalClasspathElement>

           </additionalClasspathElements>

           <includes>

             <include>**/*ItCase.java</include>

           </includes>

           <forkCount>1</forkCount>

           <reuseForks>false</reuseForks>

           <useSystemClassLoader>false</useSystemClassLoader>

         </configuration>

      </execution>

    </executions>

</plugin>