Improve IntelliJ IDE integration

[mark-vieira]

This commit makes a number of improvements when importing the
Elasticsearch project into IntelliJ IDEA. Specifically:

• Contributing documentation has been updated to reflect that the
  'idea' task should no long be used and Gradle project import is
  instead the officially supported way of setting up the project.
• Attempts to run the 'idea' task will result in a failure with a
  message directing folks to our CONTRIBUTING.md document.
• The project JDK is explicit set rather that using whatever JAVA_HOME is.
• Gradle build operation delegation is disabled, and test execution is
  configured to 'choose per test'.
• Gradle is configured to inherit the project JDK.
• Some code style conventions are automatically configured.
• File encoding is explicitly set to UTF-8.
• Parallel module compilation is enabled and deprecated feature
  warnings are disabled.
• A remote debug run configuration using listen mode is created.
• JUnit runner is configured with required system properties.
• License headers are configured such that Apache 2 is the default
  notice added to all source files with exception of source in /x-pack
  which will use the Elastic license.

Closes #46118

[elasticmachine]

Pinging @elastic/es-core-infra (:Core/Infra/Build)

[mark-vieira]

Subsequent to this PR I intend on updating our team docs as well as an explanatory email to @dev instructing folks to clean their workspaces and follow the new guidance on project import.

[rjernst]

This is great! I have one question.

[rjernst]

LGTM

[jasontedor]

LGTM.

[pugnascotia]

I checked out your branch and imported it as a fresh project in IntelliJ.

• ✅ Created a new class outside x-pack. The Apache license header was inserted, as expected
• ❌ Created a new class inside x-pack. It was created with the Apache license header instead of the Elastic license header.

Other:

• Could we configure IntelliJ to use the Eclipse formatter and our bundled format config? The downside of this is that it relies on the "Eclipse Code Formatter" plugin, though I also noticed a thing in IntelliJ about "Required Plugins", under "Build, Execution, Deployment". I tried adding the Eclipse plugin, and it created the file .idea/externalDependencies.xml with the following content:

  <?xml version="1.0" encoding="UTF-8"?>
  <project version="4">
    <component name="ExternalDependencies">
      <plugin id="EclipseCodeFormatter" />
    </component>
  </project>

  Configuring the plugin created: .idea/eclipseCodeFormatter.xml with contents:

  <?xml version="1.0" encoding="UTF-8"?>
  <project version="4">
    <component name="EclipseCodeFormatterProjectSettings">
      <option name="projectSpecificProfile">
        <ProjectSpecificProfile>
          <option name="formatter" value="ECLIPSE" />
          <option name="pathToConfigFileJava" value="$PROJECT_DIR$/.eclipseformat.xml" />
          <option name="selectedJavaProfile" value="Elasticsearch" />
        </ProjectSpecificProfile>
      </option>
    </component>
  </project>

  It's also referenced in .idea/workspace.xml:

  <project>
    <component name="PropertiesComponent">
      <property name="settings.editor.selected.configurable" value="EclipseFormatter" />

[mark-vieira]

❌ Created a new class inside x-pack. It was created with the Apache license header instead of the Elastic license header.

Where exactly? I'm not able to reproduce this locally. Perhaps there's some directory that's not betting matched by the imported scope.

[mark-vieira]

Could we configure IntelliJ to use the Eclipse formatter and our bundled format config?

Perhaps, I didn't look into using the plugin. I initially tried this by just importing the XML config itself bu that generated a huge file in the global preferences directory which would have been a pain to keep up to date. Can you create a separate issue for this. I don't want to hold up merging this for folks while we work out the code style stuff. I'm more concerned about folks having project compilation issues associated with using ./gradlew idea.

[pugnascotia]

Where exactly? I'm not able to reproduce this locally. Perhaps there's some directory that's not betting matched by the imported scope.

I literally just picked a random java file under x-pack somewhere and created another file alongside it. Did you try with a fresh location / checkout / worktree?

@jasontedor / @rjernst can you replicate, either successfully or otherwise?

[pugnascotia]

I created #53812 for the formatting stuff.

[pugnascotia]

I confirmed that commit 7eacee5 has fixed the license issue.

[mark-vieira]

@elasticmachine test this please