adds features

src/lib/zip-processing.ts

@@ -572,6 +572,25 @@ export const dissolveSubDocument = (
 const stripPdfExtension = (name: string) =>
 	name.toLowerCase().endsWith('.pdf') ? name.slice(0, -'.pdf'.length) : name;
 
+/**
+ * Build a single PDF export unit for one sub-document. The resulting filename
+ * follows the same convention as the separate archive export:
+ * `{archiveName} - {subDocumentName}` (without duplicate `.pdf` suffixes).
+ */
+export const buildSubDocumentExport = async (
+	archiveName: string,
+	subDocument: SubDocument
+): Promise<ExportUnit> => {
+	if (subDocument.attachments.length === 0) {
+		throw new Error('Cannot create a PDF from an empty sub-document.');
+	}
+
+	return {
+		name: `${stripPdfExtension(archiveName)} - ${stripPdfExtension(subDocument.name)}`,
+		bytes: await mergeAttachments(subDocument.attachments)
+	};
+};
+
 /**
  * Build one or more PDF export units from the archive.
  *
@@ -607,10 +626,7 @@ export const buildArchiveExport = async (
 			continue;
 		}
 
-		separateUnits.push({
-			name: `${stripPdfExtension(archive.name)} - ${stripPdfExtension(subDocument.name)}`,
-			bytes: await mergeAttachments(subDocument.attachments)
-		});
+		separateUnits.push(await buildSubDocumentExport(archive.name, subDocument));
 	}
 
 	if (archive.attachments.length > 0) {