I think, this is the fix:
function run() {
for (const listing of selectedListings) {
var thisBrand = "";
var thisSize = "";
var thisColour = "";
var thisPattern = "";
var thisFeatures = "";
var thisType = "";
if (!listing.attributes["Brand"] || listing.attributes["Brand"]=="") {
consoleLog("NO BRAND");
} else {
thisBrand = listing.attributes["Brand"] + " ";
}
if (!listing.attributes["Size"] || listing.attributes["Size"]=="") {
consoleLog("NO SIZE");
} else {
thisSize = "Size" + " " + listing.attributes["Size"] + " ";
}
if (!listing.attributes["Colour"] || listing.attributes["Colour"]=="") {
consoleLog("NO COLOUR");
} else {
thisColour = listing.attributes["Colour"] + " ";
}
if (!listing.attributes["Pattern"] || listing.attributes["Pattern"]=="") {
consoleLog("NO PATTERN");
} else {
thisPattern = listing.attributes["Pattern"] + " ";
}
if (!listing.attributes["Features"] || listing.attributes["Features"]=="") {
consoleLog("NO FEATURES");
} else {
thisFeatures = listing.attributes["Features"] + " ";
}
if (!listing.attributes["Type"] || listing.attributes["Type"]=="") {
consoleLog("NO TYPE");
} else {
thisType = listing.attributes["Type"] + " ";
}
listing.title = "Text" + " " + thisBrand + thisSize + thisColour + thisPattern + thisFeatures + thisType + "Text";
}
}