fix: add modified value for object

src/google-drive.ts

@@ -11,7 +11,7 @@ interface GoogleDriveCreateResponse {
     id: string;
 }
 
-const DRIVE_FIELDS = "id,name,size,mimeType,md5Checksum";
+const DRIVE_FIELDS = "id,name,size,mimeType,md5Checksum,modifiedTime";
 const FOLDER_MIME_TYPE = "application/vnd.google-apps.folder";
 const LIST_NODE_CAP = 5000;
 
@@ -227,6 +227,7 @@ export async function streamDownloadFromDrive(accessToken: string, bucket: strin
         size: parseInt(file.size || "0", 10),
         id: file.id,
         md5Checksum: file.md5Checksum,
+        modifiedTime: file.modifiedTime,
         status: downloadRes.status,
         contentRange: downloadRes.headers.get("Content-Range") ?? undefined,
         contentLength: downloadRes.headers.get("Content-Length") ?? undefined,
@@ -264,6 +265,7 @@ export async function getFileMetadata(accessToken: string, bucket: string, objec
         mimeType: file.mimeType || "application/octet-stream",
         size: parseInt(file.size || "0", 10),
         md5Checksum: file.md5Checksum,
+        modifiedTime: file.modifiedTime,
     };
 }
 

src/router.ts

@@ -207,6 +207,7 @@ export async function dispatch(request: Request, env: Env, accessToken: string,
                 ETag: `"${etag(file)}"`,
             });
             if (file.contentRange) headers.set("Content-Range", file.contentRange);
+            if (file.modifiedTime) headers.set("Last-Modified", new Date(file.modifiedTime).toUTCString());
             return new Response(file.body, { status: file.status, headers });
         } catch (error) {
             if (error instanceof Error && error.message === "File not found") return s3Error("NoSuchKey", 404, undefined, resource);
@@ -218,10 +219,9 @@ export async function dispatch(request: Request, env: Env, accessToken: string,
         if (!key) return new Response(null, { status: 200 });
         try {
             const metadata = await getFileMetadata(accessToken, bucket, key, env);
-            return new Response(null, {
-                status: 200,
-                headers: { "Content-Type": metadata.mimeType, "Content-Length": metadata.size.toString(), "Accept-Ranges": "bytes", ETag: `"${etag(metadata)}"` },
-            });
+            const headers = new Headers({ "Content-Type": metadata.mimeType, "Content-Length": metadata.size.toString(), "Accept-Ranges": "bytes", ETag: `"${etag(metadata)}"` });
+            if (metadata.modifiedTime) headers.set("Last-Modified", new Date(metadata.modifiedTime).toUTCString());
+            return new Response(null, { status: 200, headers });
         } catch (error) {
             if (error instanceof Error && error.message === "File not found") return s3Error("NoSuchKey", 404, undefined, resource, true);
             throw error;

src/types.ts

@@ -41,6 +41,7 @@ export interface DriveDownloadResult {
     size: number;
     id: string;
     md5Checksum?: string;
+    modifiedTime?: string;
     status: number;
     contentRange?: string;
     contentLength?: string;
@@ -51,4 +52,5 @@ export interface DriveFileMetadata {
     mimeType: string;
     size: number;
     md5Checksum?: string;
+    modifiedTime?: string;
 }

test/s3.test.ts

@@ -18,8 +18,11 @@ interface StoredFile {
     mimeType: string;
     data: Uint8Array;
     md5Checksum: string;
+    modifiedTime: string;
 }
 
+const FAKE_MODIFIED_TIME = "2026-08-16T08:00:00.000Z";
+
 interface StoredFolder {
     id: string;
     name: string;
@@ -95,6 +98,7 @@ class FakeDrive {
             mimeType,
             data: new Uint8Array(),
             md5Checksum: "d41d8cd98f00b204e9800998ecf8427e",
+            modifiedTime: FAKE_MODIFIED_TIME,
         };
         this.files.set(id, file);
         return Response.json({ ...file, size: "0", data: undefined });
@@ -148,7 +152,7 @@ class FakeDrive {
 
     private finalize(session: UploadSession, data: Uint8Array): Response {
         const id = session.fileId ?? `file-${this.nextId++}`;
-        const file: StoredFile = { id, name: session.name, parent: session.parent, mimeType: session.mimeType, data, md5Checksum: fakeMd5(data) };
+        const file: StoredFile = { id, name: session.name, parent: session.parent, mimeType: session.mimeType, data, md5Checksum: fakeMd5(data), modifiedTime: FAKE_MODIFIED_TIME };
         this.files.set(id, file);
         this.sessions.delete(session.id);
         return Response.json({ ...file, size: String(data.byteLength), data: undefined });
@@ -225,6 +229,18 @@ describe("S3 compatibility", () => {
         expect(new TextDecoder().decode([...drive.files.values()].find((file) => file.name === "file.txt")!.data)).toBe("second");
     });
 
+    it("sets Last-Modified on GET and HEAD from Drive's modifiedTime", async () => {
+        await worker.fetch(await signed("/test-bucket/dated.txt", { method: "PUT", body: "hi" }), ENV, CTX);
+
+        const expected = new Date(FAKE_MODIFIED_TIME).toUTCString();
+
+        const get = await worker.fetch(await signed("/test-bucket/dated.txt", { method: "GET" }), ENV, CTX);
+        expect(get.headers.get("Last-Modified")).toBe(expected);
+
+        const head = await worker.fetch(await signed("/test-bucket/dated.txt", { method: "HEAD" }), ENV, CTX);
+        expect(head.headers.get("Last-Modified")).toBe(expected);
+    });
+
     it("forwards Range and returns a standard XML NoSuchKey", async () => {
         await worker.fetch(await signed("/test-bucket/range.bin", { method: "PUT", body: "0123456789" }), ENV, CTX);
         const response = await worker.fetch(await signed("/test-bucket/range.bin", { method: "GET", headers: { Range: "bytes=2-5" } }), ENV, CTX);