fix(lint-errors): resolve ESLint formatting and type safety issues

Author: Crushdada

README.md

@@ -267,7 +267,7 @@ The MongoDB MCP Server can be configured using multiple methods, with the follow
 | `logPath`          | Folder to store logs.                                                                                                                                         |
 | `disabledTools`    | An array of tool names, operation types, and/or categories of tools that will be disabled.                                                                    |
 | `readOnly`         | When set to true, only allows read and metadata operation types, disabling create/update/delete operations.                                                   |
-| `indexCheck`       | When set to true, enforces that query operations must use an index, rejecting queries that perform a collection scan.                                           |
+| `indexCheck`       | When set to true, enforces that query operations must use an index, rejecting queries that perform a collection scan.                                         |
 | `telemetry`        | When set to disabled, disables telemetry collection.                                                                                                          |
 
 #### Log Path

src/helpers/indexCheck.ts

@@ -2,15 +2,16 @@ import { Document } from "mongodb";
 import { NodeDriverServiceProvider } from "@mongosh/service-provider-node-driver";
 import { ErrorCodes, MongoDBError } from "../errors.js";
 
-
 /**
  * Check if the query plan uses an index
  * @param explainResult The result of the explain query
  * @returns true if an index is used, false if it's a full collection scan
  */
 export function usesIndex(explainResult: Document): boolean {
-    const stage = explainResult?.queryPlanner?.winningPlan?.stage;
-    const inputStage = explainResult?.queryPlanner?.winningPlan?.inputStage;
+    const queryPlanner = explainResult?.queryPlanner as Document | undefined;
+    const winningPlan = queryPlanner?.winningPlan as Document | undefined;
+    const stage = winningPlan?.stage as string | undefined;
+    const inputStage = winningPlan?.inputStage as Document | undefined;
 
     // Check for index scan stages (including MongoDB 8.0+ stages)
     const indexScanStages = [
@@ -20,14 +21,14 @@ export function usesIndex(explainResult: Document): boolean {
         "EXPRESS_CLUSTERED_IXSCAN",
         "EXPRESS_UPDATE",
         "EXPRESS_DELETE",
-        "IDHACK"
+        "IDHACK",
     ];
 
-    if (indexScanStages.includes(stage)) {
+    if (stage && indexScanStages.includes(stage)) {
         return true;
     }
 
-    if (inputStage && indexScanStages.includes(inputStage.stage)) {
+    if (inputStage && inputStage.stage && indexScanStages.includes(inputStage.stage as string)) {
         return true;
     }
 
@@ -65,7 +66,10 @@ export async function checkIndexUsage(
         const explainResult = await explainCallback();
 
         if (!usesIndex(explainResult)) {
-            throw new MongoDBError(ErrorCodes.ForbiddenCollscan, getIndexCheckErrorMessage(database, collection, operation));
+            throw new MongoDBError(
+                ErrorCodes.ForbiddenCollscan,
+                getIndexCheckErrorMessage(database, collection, operation)
+            );
         }
     } catch (error) {
         if (error instanceof Error && error.message.includes("Index check failed")) {
@@ -76,4 +80,4 @@ export async function checkIndexUsage(
         // This avoids blocking normal queries in special cases (e.g., permission issues)
         console.warn(`Index check failed to execute explain for ${operation} on ${database}.${collection}:`, error);
     }
-}
+}

src/tools/mongodb/mongodbTool.ts

@@ -64,6 +64,16 @@ export abstract class MongoDBToolBase extends ToolBase {
                         ],
                         isError: true,
                     };
+                case ErrorCodes.ForbiddenCollscan:
+                    return {
+                        content: [
+                            {
+                                type: "text",
+                                text: error.message,
+                            },
+                        ],
+                        isError: true,
+                    };
             }
         }
 

src/tools/mongodb/read/find.ts

@@ -44,9 +44,7 @@ export class FindTool extends MongoDBToolBase {
         // Check if find operation uses an index if enabled
         if (this.config.indexCheck) {
             await checkIndexUsage(provider, database, collection, "find", async () => {
-                return provider
-                    .find(database, collection, filter, { projection, limit, sort })
-                    .explain("queryPlanner");
+                return provider.find(database, collection, filter, { projection, limit, sort }).explain("queryPlanner");
             });
         }
 

tests/unit/indexCheck.test.ts

@@ -146,4 +146,4 @@ describe("indexCheck", () => {
             expect(message).toContain("MDB_MCP_INDEX_CHECK");
         });
     });
-});
+});