Clean up MongoDB query projection

This prevents potential 'path collision' errors from MongoDB.

lib/db.ts

@@ -91,7 +91,9 @@ export async function disconnect(): Promise<void> {
 
 // Optimize projection by removing overlaps
 // This can modify the object
-function optimizeProjection(obj: { [path: string]: 1 }): { [path: string]: 1 } {
+export function optimizeProjection(obj: { [path: string]: 1 }): {
+  [path: string]: 1;
+} {
   if (obj[""]) return { "": obj[""] };
 
   const keys = Object.keys(obj).sort();

lib/nbi.ts

@@ -21,7 +21,7 @@ import * as url from "url";
 import { Collection, GridFSBucket, ObjectId } from "mongodb";
 import * as vm from "vm";
 import * as config from "./config";
-import { onConnect } from "./db";
+import { onConnect, optimizeProjection } from "./db";
 import * as query from "./query";
 import * as apiFunctions from "./api-functions";
 import { IncomingMessage, ServerResponse } from "http";
@@ -821,6 +821,7 @@ export function listener(
         projection = {};
         for (const p of (urlParts.query.projection as string).split(","))
           projection[p.trim()] = 1;
+        projection = optimizeProjection(projection);
       }
 
       const cur = collection.find(q, { projection: projection });

lib/ui/db.ts

@@ -19,7 +19,7 @@
 
 import { Db, GridFSBucket, ObjectId } from "mongodb";
 import { Script } from "vm";
-import { onConnect } from "../db";
+import { onConnect, optimizeProjection } from "../db";
 import * as mongodbFunctions from "../mongodb-functions";
 import * as expression from "../common/expression";
 import { QueryOptions, Expression } from "../types";
@@ -89,6 +89,7 @@ export function query(
       }
 
       if (resource === "presets") projection.configurations = 1;
+      projection = optimizeProjection(projection);
       cursor.project(projection);
     }