[Maven plugin] importOrder with order element does not work as expected

[Xendar]

I am currently implementing Spotless (plugin version 2.5.0) in a Maven project (3.6.3) and it seems that the importOrder does not work as expected when using the order element.

Maven configuration:

<configuration>
  <ratchetFrom>origin/main</ratchetFrom>
  <java>
    <importOrder>
      <order>java,javafx,com.mycompany,</order>
    </importOrder>
    <removeUnusedImports />
    <toggleOffOn />
    <eclipse>
      <file>${basedir}/config/formatter.xml</file>
    </eclipse>
    <licenseHeader>
      <file>${basedir}/config/header</file>
    </licenseHeader>
  </java>
</configuration>

After running the spotless:apply goal I get this formatting:

package com.mycompany.mytool;

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

import javafx.beans.property.ObjectProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.concurrent.Task;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.geometry.Insets;
import javafx.scene.Node;
import javafx.scene.control.Button;
import javafx.scene.control.ComboBox;
import javafx.scene.control.Control;
import javafx.scene.control.Label;
import javafx.scene.control.PasswordField;
import javafx.scene.control.RadioButton;
import javafx.scene.control.TextField;
import javafx.scene.control.ToggleGroup;
import javafx.scene.image.ImageView;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;

import lombok.Getter;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.controlsfx.control.PopOver;
import org.controlsfx.control.PopOver.ArrowLocation;
import org.controlsfx.control.textfield.CustomTextField;
import org.controlsfx.control.textfield.TextFields;
import org.controlsfx.validation.Severity;
import org.controlsfx.validation.ValidationResult;
import org.controlsfx.validation.ValidationSupport;
import org.controlsfx.validation.Validator;
import org.controlsfx.validation.decoration.GraphicValidationDecoration;

import com.mycompany.mytool.api.SomeApi;
import com.mycompany.mytool.impl.SomeImpl;
import com.mycompany.mytool.javafx.SomeJavaFX;

import com.google.inject.Inject;
import com.google.inject.name.Named;

Now if I use an importorder file:

3=
2=com.mycompany
1=javafx
0=java

And reference it in the Maven configuration:

<configuration>
  <ratchetFrom>origin/main</ratchetFrom>
  <java>
    <importOrder>
      <!--order>java,javafx,com.mycompany,</order-->
      <file>${basedir}/config/importorder</file>
    </importOrder>
    <removeUnusedImports />
    <toggleOffOn />
    <eclipse>
      <file>${basedir}/config/formatter.xml</file>
    </eclipse>
    <licenseHeader>
      <file>${basedir}/config/header</file>
    </licenseHeader>
  </java>
</configuration>

And running again the spotless:apply goal then I get this formatting:

package com.mycompany.mytool;

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

import javafx.beans.property.ObjectProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.concurrent.Task;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.geometry.Insets;
import javafx.scene.Node;
import javafx.scene.control.Button;
import javafx.scene.control.ComboBox;
import javafx.scene.control.Control;
import javafx.scene.control.Label;
import javafx.scene.control.PasswordField;
import javafx.scene.control.RadioButton;
import javafx.scene.control.TextField;
import javafx.scene.control.ToggleGroup;
import javafx.scene.image.ImageView;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;

import com.mycompany.mytool.api.SomeApi;
import com.mycompany.mytool.impl.SomeImpl;
import com.mycompany.mytool.javafx.SomeJavaFX;

import com.google.inject.Inject;
import com.google.inject.name.Named;
import lombok.Getter;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.controlsfx.control.PopOver;
import org.controlsfx.control.PopOver.ArrowLocation;
import org.controlsfx.control.textfield.CustomTextField;
import org.controlsfx.control.textfield.TextFields;
import org.controlsfx.validation.Severity;
import org.controlsfx.validation.ValidationResult;
import org.controlsfx.validation.ValidationSupport;
import org.controlsfx.validation.Validator;
import org.controlsfx.validation.decoration.GraphicValidationDecoration;

There is no error nor warning in the console.
It's a private repo so I cannot share it, but I can try to create a public one to reproduce.
Can it be linked to the usage of split method (https://github.com/diffplug/spotless/blob/main/plugin-maven/src/main/java/com/diffplug/spotless/maven/java/ImportOrder.java#L41), that discards the 'empty' recommended last element?

      <order>java,javax,org,com,com.diffplug,</order>  <!-- or use <file>${basedir}/eclipse.importorder</file> -->
      <!-- You probably want an empty string at the end - all of the
           imports you didn't specify explicitly will go there. -->

[nedtwigg]

Published in plugin-gradle 5.8.1 and plugin-maven 2.6.0.