How to add a JComponent to pre-existing Run configuration editor

Please see com.jetbrains.nodejs.run.NodeJSRunConfigurationExtension, EP: NodeJS.runConfigurationExtension.

It extends generic com.intellij.execution.configuration.RunConfigurationExtensionBase (samples: https://plugins.jetbrains.com/intellij-platform-explorer?extensions=com.intellij.runConfigurationExtension), see its javadoc

Yann Cebron thanks for answer, could you please expand a little bit on this?
I guess the first thing would be to create a class that extends the

NodeJSRunConfigurationExtension

Like this

public class NodejsExtendedConfigurationEditor extends NodeJSRunConfigurationExtension {
    @Override
    protected @Nullable NodeJSRuntimeSession createLocalRuntimeSession(@NotNull NodeJsRunConfiguration nodeJsRunConfiguration, @NotNull ExecutionEnvironment executionEnvironment) throws ExecutionException {
        return null;
    }

    @Override
    protected @Nullable NodeJSRuntimeSession createRemoteRuntimeSession(@NotNull NodeJsRunConfiguration nodeJsRunConfiguration, @NotNull ExecutionEnvironment executionEnvironment, @NotNull NodeFileTransfer nodeFileTransfer) throws ExecutionException {
        return null;
    }

    @Override
    protected @Nullable SettingsEditor<NodeJsRunConfiguration> createEditor(@NotNull NodeJsRunConfiguration configuration, Consumer<NodeJsInterpreterChangeListener> listenerRegistrar) {
        return super.createEditor(configuration, listenerRegistrar);
    }

    @Override
    public boolean isApplicableFor(@NotNull NodeJsRunConfiguration configuration) {
        return true;
    }

    @Override
    public boolean isEnabledFor(@NotNull NodeJsRunConfiguration applicableConfiguration, @Nullable RunnerSettings runnerSettings) {
        return true;
    }
}

Maybe modify the create editor function and add my custom component?

@Override
protected @Nullable <P extends NodeJsRunConfiguration> SettingsEditor<P> createEditor(@NotNull P configuration) {
    SettingsEditor<P> editor = super.createEditor(configuration);
    editor.getComponent().add(new JLabel("Hello"));
    return editor;
}

And maybe add it to my plugin.xml as dependency?

<depends config-file="myPluginId-nodejsExtension.xml">NodeJS</depends>

<idea-plugin>
    <extensions defaultExtensionNs="NodeJS">
        <runConfigurationExtension
                implementation="com.github.user.repository.NodejsCustomRunConfigurationExtension"
                id="myPluginId-nodejsExtension"
        />
    </extensions>
</idea-plugin>

However like this nothing happens, the createEditor won't get called.
Thanks

1) com.intellij.execution.configuration.RunConfigurationExtensionBase#createEditor returns null by default, you need to return your custom instance see com.intellij.execution.coverage.CoverageJavaRunConfigurationExtension from Java plugin as sample

2) Override com.intellij.execution.configuration.RunConfigurationExtensionBase#getEditorTitle

3) return false from com.jetbrains.nodejs.run.NodeJSRunConfigurationExtension#showEditorInMainPage

4) your plugin.xml "implementation" doesn't match the class name (

NodejsExtendedConfigurationEditor vs

NodejsCustomRunConfigurationExtension)

Was `com.jetbrains.nodejs.run.NodeJSRunConfigurationExtension` (that is mentioned a lot in this thread) removed or something? I get `Unresolved reference: NodeJSRunConfigurationExtension` when I try to import it (but not for `com.jetbrains.nodejs.run.NodeJsRunConfiguration`, so I think I do have the JavaScript plugin).

And where is all of this documented actually, or where is the source code if there's no documentation?

How do people know about those classes and their members?

Thank you for the clarification, Yann Cebron. Unlike in e.g. `PythonRunConfigurationExtension`, in `AbstractNodeRunConfigurationExtension`, `patchCommandLine` is final. So how can we offer a similar functionality for node?