ScriptedImporterAttribute.fileExtensions

Description

List of file name extensions (not including the leading period character) that the scripted importer handles.

using UnityEngine;
using UnityEditor.AssetImporters;

[ScriptedImporter(1, new[] {"cb", "cube"})]
public class CubeImporter : ScriptedImporter
{
    public override void OnImportAsset(AssetImportContext ctx)
    {
        // ...
    }
}