added guard on documents.fonts

lib/single-file/doc-helper.js

@@ -81,7 +81,11 @@ this.docHelper = this.docHelper || (() => {
 					elementsInfo = new Map(Array.from(elementsInfo).filter(([element]) => element.getAttribute(markerRemovedContent) != ""));
 				}
 				if (options.removeUnusedStyles) {
-					usedFonts = getUsedFonts(elementsInfo, Array.from(doc.fonts).filter(font => font.status == "loaded" || font.status == "loading"));
+					let loadedFonts;
+					if (doc.fonts) {
+						loadedFonts = Array.from(doc.fonts).filter(font => font.status == "loaded" || font.status == "loading");
+					}
+					usedFonts = getUsedFonts(elementsInfo, loadedFonts);
 				}
 				if (options.compressHTML) {
 					elementsInfo.forEach((elementInfo, element) => {
@@ -122,7 +126,7 @@ this.docHelper = this.docHelper || (() => {
 			const fontFamilyNames = style.fontFamily.split(",");
 			fontFamilyNames.forEach(fontFamilyName => {
 				fontFamilyName = removeQuotes(fontFamilyName.trim()).toLowerCase();
-				if (loadedFonts.find(font => font.family.toLowerCase() == fontFamilyName && font.style == style.fontStyle && font.weight == style.fontWeight && font.weight == style.fontWeight && font.variant == style.fontVariant)) {
+				if (!loadedFonts || loadedFonts.find(font => font.family.toLowerCase() == fontFamilyName && font.style == style.fontStyle && font.weight == style.fontWeight && font.weight == style.fontWeight && font.variant == style.fontVariant)) {
 					const { fontWeight, fontStyle, fontVariant } = style;
 					usedFonts.add([fontFamilyName, fontWeight, fontStyle, fontVariant]);
 				}