package com.simpleplugin;

import com.intellij.openapi.fileTypes.*;
import org.jetbrains.annotations.NotNull;

public class SimpleFileTypeFactory extends FileTypeFactory {
  @Override
  public void createFileTypes(@NotNull FileTypeConsumer fileTypeConsumer) {
    fileTypeConsumer.consume(SimpleFileType.INSTANCE, "simple");
  }
}
@@ -309,22 +309,12 @@
 ANCE
-, %22simple%22
 );%0A  %7D%0A%7D
@@ -313,8 +313,9 @@
 );%0A  %7D%0A%7D
+%0A

Remove passing a file extension explicitly.