feat: ensure filename when downloading file

components/documents/document-header.tsx

@@ -32,7 +32,7 @@ import {
   DocumentWithLinksAndLinkCountAndViewCount,
   DocumentWithVersion,
 } from "@/lib/types";
-import { cn } from "@/lib/utils";
+import { cn, ensureFileExtension } from "@/lib/utils";
 import { supportsAdvancedExcelMode } from "@/lib/utils/get-content-type";
 import { fileIcon } from "@/lib/utils/get-file-icon";
 
@@ -477,7 +477,10 @@ export default function DocumentHeader({
         const url = window.URL.createObjectURL(blob);
         const a = document.createElement("a");
         a.href = url;
-        a.download = prismaDocument.name;
+        a.download = ensureFileExtension(prismaDocument.name, {
+          type: documentVersion.type || undefined,
+          contentType: documentVersion.contentType || undefined,
+        });
         document.body.appendChild(a);
         a.click();
         window.URL.revokeObjectURL(url);

components/view/dataroom/document-card.tsx

@@ -6,7 +6,7 @@ import { Download, MoreVerticalIcon } from "lucide-react";
 import { useTheme } from "next-themes";
 import { toast } from "sonner";
 
-import { timeAgo } from "@/lib/utils";
+import { ensureFileExtension, timeAgo } from "@/lib/utils";
 import { cn } from "@/lib/utils";
 import { fileIcon } from "@/lib/utils/get-file-icon";
 import {
@@ -136,7 +136,10 @@ export default function DocumentCard({
           disposition && disposition.match(/filename="(.+)"/);
         link.download = filenameMatch
           ? decodeURIComponent(filenameMatch[1])
-          : document.name;
+          : ensureFileExtension(document.name, {
+              type: document.versions[0]?.type || undefined,
+              contentType: document.versions[0]?.contentType || undefined,
+            });
         link.rel = "noopener noreferrer";
         window.document.body.appendChild(link);
         link.click();

components/view/viewer/dataroom-viewer.tsx

@@ -91,6 +91,7 @@ export type DocumentVersion = {
   hasPages: boolean;
   isVertical: boolean;
   updatedAt: Date;
+  contentType: string;
 };
 
 type DataroomDocument = {

components/view/viewer/pdf-default-viewer.tsx

@@ -6,6 +6,7 @@ import { Document, Page, pdfjs } from "react-pdf";
 
 import { useSafePageViewTracker } from "@/lib/tracking/safe-page-view-tracker";
 import { getTrackingOptions } from "@/lib/tracking/tracking-config";
+import { ensureFileExtension } from "@/lib/utils";
 
 import Nav from "@/components/view/nav";
 
@@ -231,7 +232,7 @@ export default function PDFViewer(props: any) {
       //create <a/> to download the file
       const a = document.createElement("a");
       a.href = window.URL.createObjectURL(fileData);
-      a.download = props.name;
+      a.download = ensureFileExtension(props.name, { type: "pdf" });
       document.body.appendChild(a);
       a.click();
 

lib/api/links/link-data.ts

@@ -141,6 +141,7 @@ export async function fetchDataroomLinkData({
                       file: true,
                       isVertical: true,
                       updatedAt: true,
+                      contentType: true,
                     },
                     take: 1,
                   },
@@ -323,6 +324,7 @@ export async function fetchDataroomDocumentLinkData({
                       hasPages: true,
                       file: true,
                       isVertical: true,
+                      contentType: true,
                     },
                     take: 1,
                   },

lib/utils.ts

@@ -15,6 +15,8 @@ import { ParsedUrlQuery } from "querystring";
 import { toast } from "sonner";
 import { twMerge } from "tailwind-merge";
 
+import { getExtensionFromContentType } from "./utils/get-content-type";
+
 export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs));
 }
@@ -41,6 +43,69 @@ export function getFileNameWithPdfExtension(filename?: string): string {
   return `${nameWithoutExt}.pdf`;
 }
 
+/**
+ * Ensures a filename has the correct file extension based on document type or contentType
+ * If the filename already has an extension, it is preserved.
+ * If not, the appropriate extension is added based on the provided type/contentType.
+ */
+export function ensureFileExtension(
+  filename?: string,
+  options?: {
+    type?: string;
+    contentType?: string;
+  },
+): string {
+  if (!filename) return "document";
+
+  // Check if filename already has an extension
+  const hasExtension = /\.[^/.]+$/.test(filename);
+
+  if (hasExtension) {
+    return filename;
+  }
+
+  // If no extension, determine the appropriate one
+  let extension = "";
+
+  // First try to get extension from contentType if provided
+  if (options?.contentType) {
+    const ext = getExtensionFromContentType(options.contentType);
+    if (ext) {
+      extension = ext;
+    }
+  }
+
+  // If no extension from contentType, try using the document type
+  if (!extension && options?.type) {
+    switch (options.type) {
+      case "pdf":
+        extension = "pdf";
+        break;
+      case "image":
+        extension = "png"; // default image extension
+        break;
+      case "sheet":
+        extension = "xlsx";
+        break;
+      case "docs":
+        extension = "docx";
+        break;
+      case "slides":
+        extension = "pptx";
+        break;
+      case "video":
+        extension = "mp4";
+        break;
+      default:
+        // No extension determined
+        break;
+    }
+  }
+
+  // Return filename with extension if one was determined
+  return extension ? `${filename}.${extension}` : filename;
+}
+
 interface SWRError extends Error {
   status: number;
 }

pages/api/links/download/dataroom-document.ts

@@ -6,7 +6,7 @@ import { waitUntil } from "@vercel/functions";
 import { getFile } from "@/lib/files/get-file";
 import { notifyDocumentDownload } from "@/lib/integrations/slack/events";
 import prisma from "@/lib/prisma";
-import { getFileNameWithPdfExtension } from "@/lib/utils";
+import { ensureFileExtension, getFileNameWithPdfExtension } from "@/lib/utils";
 import { getIpAddress } from "@/lib/utils/ip";
 
 export const config = {
@@ -281,7 +281,15 @@ export default async function handle(
         res.setHeader("Content-Type", "application/pdf");
         res.setHeader(
           "Content-Disposition",
-          `attachment; filename="${encodeURIComponent(downloadDocuments[0].document!.name)}"`,
+          `attachment; filename="${encodeURIComponent(
+            ensureFileExtension(downloadDocuments[0].document!.name, {
+              type:
+                downloadDocuments[0].document!.versions[0].type || undefined,
+              contentType:
+                downloadDocuments[0].document!.versions[0].contentType ||
+                undefined,
+            }),
+          )}"`,
         );
         res.setHeader("Content-Length", Buffer.from(pdfBuffer).length);
         res.setHeader("Cache-Control", "no-cache");
@@ -295,7 +303,14 @@ export default async function handle(
         downloadDocuments[0].document!.versions[0].contentType ||
         headResponse.headers.get("content-type") ||
         "application/octet-stream";
-      const fileName = downloadDocuments[0].document!.name;
+      const fileName = ensureFileExtension(
+        downloadDocuments[0].document!.name,
+        {
+          type: downloadDocuments[0].document!.versions[0].type || undefined,
+          contentType:
+            downloadDocuments[0].document!.versions[0].contentType || undefined,
+        },
+      );
 
       // For all other files, return direct download URL
       return res.status(200).json({