cat << END > expected
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE Map[]>
<Map srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over">
  <Style filter-mode="first" name="world">
    <Rule>
      <PolygonSymbolizer fill="#008000" />
      <LineSymbolizer stroke="#f0e6db" />
    </Rule>
  </Style>
  <Layer name="world" srs="+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over">
    <StyleName><![CDATA[world]]></StyleName>
  </Layer>
</Map>

END

carto test/rendering/layer_nodatasource.mml | diff - expected
rm expected
