fix: Cannot create collection if all collections deleted

server/api/collections.js

@@ -74,7 +74,10 @@ router.post("collections.create", auth(), async (ctx) => {
       );
     }
   } else {
-    index = fractionalIndex(null, collections[0].index);
+    index = fractionalIndex(
+      null,
+      collections.length ? collections[0].index : null
+    );
   }
 
   index = await removeIndexCollision(user.teamId, index);

server/api/collections.test.js

@@ -1002,7 +1002,7 @@ describe("#collections.create", () => {
   });
 
   it("should create collection", async () => {
-    const { user } = await seed();
+    const user = await buildUser();
     const res = await server.post("/api/collections.create", {
       body: { token: user.getJwtToken(), name: "Test" },
     });