update: update Compile Kotlin and Java sources in Maven

[koshachy]

No description provided.

[github-actions]

This PR is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 7 days.

[ALikhachev]

I would suggest additionally highlighting that in the setup Kotlin + Java, we need to let Kotlin compiler know about the Java sources, so that's why we configure ${project.basedir}/src/main/java as a source directory for Kotlin. That is required for Kotlin -> Java references.

[ALikhachev]

It seems that actually this <extensions>true</extensions> does not make any sense. According to the previous comments, it could help avoid some configuration, but that does not appear to be true in Kotlin + Java in this particular configuration.

However, if we modify the example to

    <plugins>
      <!-- Kotlin compiler plugin -->
      <plugin>
        <groupId>org.jetbrains.kotlin</groupId>
        <artifactId>kotlin-maven-plugin</artifactId>
        <version>${kotlin.version}</version>
        <extensions>true</extensions>
        <executions>
          <execution>
            <id>default-compile</id>
            <phase>compile</phase>
            <configuration>
              <sourceDirs>
                <sourceDir>${project.basedir}/src/main/kotlin</sourceDir>
                <sourceDir>${project.basedir}/src/main/java</sourceDir>
              </sourceDirs>
            </configuration>
          </execution>
          <execution>
            <id>default-test-compile</id>
            <phase>test-compile</phase>
            <configuration>
              <sourceDirs>
                <sourceDir>${project.basedir}/src/test/kotlin</sourceDir>
                <sourceDir>${project.basedir}/src/test/java</sourceDir>
              </sourceDirs>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>

we can completely skip the Java plugin configuration and it would just work, thanks to the <extensions> setup. This configuration indeed seems much easier and shows benefit of extensions

Note that I changed execution IDs in this example.

I would suggest introducing something similar to how we show Kotlin/Groovy scripts, aka "tabs" for showing configuration with <extensions>true</extensions> and without it.

[ALikhachev]

Oh, interesting, I tried just copy-pasting the setup (both before any changes and from this PR) on top of pure Kotlin setup – it leads to incorrect configuration when Java code can see Kotlin code, but Kotlin code cannot see Java.

Either removing the extensions setup or removing of the following configuration helps.

<sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
<testSourceDirectory>${project.basedir}/src/test/kotlin</testSourceDirectory>

With the abovementioned change of execution id, it works fine. That's because setup from extensions creates executions default-compile and default-test-compile

[github-actions]

This PR is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 7 days.

[github-actions]

This PR is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 7 days.