Fix it

Fixes #8362

Author: dragonstyle

src/core/csl.ts

@@ -165,7 +165,7 @@ export function suggestId(author: CSLName[], date?: CSLDate) {
 // See https://www.loc.gov/standards/datetime/
 // Currently omits time component so this isn't truly level 0
 export function cslDateToEDTFDate(date: CSLDate) {
-  if (date["date-parts"]) {
+  if (date["date-parts"] && date["date-parts"].length > 0) {
     const paddedParts = date["date-parts"][0].map((part) => {
       const partStr = part?.toString();
       if (partStr?.length === 1) {

src/format/html/format-html-meta.ts

@@ -136,16 +136,21 @@ function googleScholarMeta(
 
   if (csl.issued) {
     const edtfIssued = cslDateToEDTFDate(csl.issued);
-    write("citation_publication_date", edtfIssued);
-    write("citation_cover_date", edtfIssued);
+    if (edtfIssued) {
+      write("citation_publication_date", edtfIssued);
+      write("citation_cover_date", edtfIssued);
+    }
     const parts = csl.issued["date-parts"];
-    if (parts) {
+    if (parts && parts.length > 0) {
       write("citation_year", parts[0][0]);
     }
   }
 
   if (csl["available-date"]) {
-    write("citation_online_date", cslDateToEDTFDate(csl["available-date"]));
+    const edtfAvailable = cslDateToEDTFDate(csl["available-date"]);
+    if (edtfAvailable) {
+      write("citation_online_date", edtfAvailable);
+    }
   }
 
   if (csl.URL) {