fix: retry media materialization after cleanup race

src/media/store.test.ts

@@ -303,6 +303,37 @@ describe("media store", () => {
         });
       },
     },
+    {
+      name: "retries buffer materialization when cleanup prunes the target dir",
+      run: async () => {
+        await withTempStore(async (store) => {
+          const originalMkdir = fs.mkdir.bind(fs);
+          let pruned = false;
+          vi.spyOn(fs, "mkdir").mockImplementation(async (...args) => {
+            const result = await originalMkdir(...args);
+            const target = args[0];
+            if (
+              !pruned &&
+              typeof target === "string" &&
+              path.normalize(target).endsWith(`${path.sep}media${path.sep}materialization-race`)
+            ) {
+              pruned = true;
+              await fs.rm(target, { force: true, recursive: true });
+            }
+            return result;
+          });
+
+          const saved = await store.saveMediaBuffer(
+            Buffer.from("race bytes"),
+            "text/plain",
+            "materialization-race",
+          );
+
+          expect(pruned).toBe(true);
+          await expect(fs.readFile(saved.path, "utf8")).resolves.toBe("race bytes");
+        });
+      },
+    },
     {
       name: "rejects traversal media subdirs before saving buffers",
       run: async () => {

src/media/store.ts

@@ -661,18 +661,20 @@ async function materializeMediaBufferPath(params: {
   buffer: Buffer;
 }): Promise<string> {
   const dir = resolveMediaScopedDir(params.subdir, "materializeMediaBufferPath");
-  await fs.mkdir(dir, { recursive: true, mode: 0o700 });
-  const written = await writeSiblingTempFile({
-    dir,
-    mode: MEDIA_FILE_MODE,
-    tempPrefix: `.${params.id}`,
-    writeTemp: async (tempPath) => {
-      await fs.writeFile(tempPath, params.buffer, { mode: MEDIA_FILE_MODE });
-      return undefined;
-    },
-    resolveFinalPath: () => path.join(dir, params.id),
+  return await retryAfterRecreatingDir(dir, async () => {
+    await fs.mkdir(dir, { recursive: true, mode: 0o700 });
+    const written = await writeSiblingTempFile({
+      dir,
+      mode: MEDIA_FILE_MODE,
+      tempPrefix: `.${params.id}`,
+      writeTemp: async (tempPath) => {
+        await fs.writeFile(tempPath, params.buffer, { mode: MEDIA_FILE_MODE });
+        return undefined;
+      },
+      resolveFinalPath: () => path.join(dir, params.id),
+    });
+    return written.filePath;
   });
-  return written.filePath;
 }
 
 async function writeMediaStreamToFile(params: {