From e4e6fdf843846858f82a715e81e908231e575b61 Mon Sep 17 00:00:00 2001
From: "Navy.gif" <navydotgif@gmail.com>
Date: Fri, 11 Aug 2023 13:03:38 +0300
Subject: [PATCH] handle index mismatches properly

---
 src/MongoDB.ts | 75 ++++++++++++++++++++++++++++++++++----------------
 1 file changed, 51 insertions(+), 24 deletions(-)

diff --git a/src/MongoDB.ts b/src/MongoDB.ts
index 4312ad1..7d2089a 100644
--- a/src/MongoDB.ts
+++ b/src/MongoDB.ts
@@ -1,5 +1,5 @@
 import { inspect } from 'node:util';
-import { MongoClient, MongoClientOptions, Db, Document, WithId, ObjectId, Filter, IndexSpecification, CreateIndexesOptions, FindOptions, MongoServerError } from 'mongodb';
+import { MongoClient, MongoClientOptions, Db, Document, WithId, ObjectId, Filter, IndexSpecification, CreateIndexesOptions, FindOptions } from 'mongodb';
 import { IServer, ILogger, LoggerClientOptions } from './interfaces/index.js';
 
 type Credentials = {
@@ -24,6 +24,20 @@ export type MongoOptions = {
     load?: boolean
 }
 
+type StringIndexable = {[key: string]: boolean | string | number | Document | object}
+
+const objIsSubset = (superObj: StringIndexable, subObj: StringIndexable): boolean =>
+{
+    return Object.keys(subObj).every(ele => 
+    {
+        if (typeof subObj[ele] === 'object' && typeof superObj[ele] === 'object') 
+        {
+            return objIsSubset(superObj[ele] as StringIndexable, subObj[ele] as StringIndexable);
+        }
+        return subObj[ele] === superObj[ele];
+    });
+};
+
 /**
  * A dedicated class to locally wrap the mongodb API wrapper
  *
@@ -363,36 +377,25 @@ class MongoDB
         return this.#db.collection(coll).countDocuments(query);
     }
 
-    async ensureIndex (collection: string, index: IndexSpecification, options?: CreateIndexesOptions): Promise<void>
+    async ensureIndex (collection: string, index: IndexSpecification, options?: CreateIndexesOptions & StringIndexable): Promise<void>
     {
         if (!this.#db)
             return Promise.reject(new Error('MongoDB not connected'));
         if (!(index instanceof Array))
             index = [ index ];
-        try 
-        {
-            await this.#db.collection(collection).createIndex(index, options); 
-        }
-        catch (err) 
-        {
-            // If the index exists, recreate it with the new spec
-            const error = err as MongoServerError;
-            // Mongo changes the given name of the index to reflect the direciton, so find it by matching the start of the name
-            const indexes = await this.#db.collection(collection).indexes();
-            const existing = indexes.find(idx => idx.name.startsWith(index));
-            if (error.codeName === 'IndexKeySpecsConflict' && existing) 
-            {
-                await this.#db.collection(collection).dropIndex(existing.name);
-                await this.#db.collection(collection).createIndex(index, options);
-            }
-            else
-            {
-                throw error; 
-            }
-        }
+        
+        const indexes = await this.#db.collection(collection).indexes();
+        const existing = indexes.find(idx => idx.name.startsWith(index));
+        if (existing && this.#indexesEqual(existing, options))
+            return;
+
+        if (existing)
+            await this.#db.collection(collection).dropIndex(existing.name);
+
+        await this.#db.collection(collection).createIndex(index, options);
     }
 
-    async ensureIndices (collection: string, indices: IndexSpecification[], options?: CreateIndexesOptions): Promise<void>
+    async ensureIndices (collection: string, indices: IndexSpecification[], options?: CreateIndexesOptions & StringIndexable): Promise<void>
     {
         if (!this.#db)
             return Promise.reject(new Error('MongoDB not connected'));
@@ -400,6 +403,30 @@ class MongoDB
             await this.ensureIndex(collection, index, options);
     }
 
+    #indexesEqual (existing: Document, options?: CreateIndexesOptions & StringIndexable) 
+    {
+        // 3 keys on the existing means that only the name was given
+        if (!options && Object.keys(existing).length === 3)
+            return true;
+        else if (!options)
+            return false;
+
+        const keys = Object.keys(options);
+        for (const key of keys) 
+        {
+            if (typeof options[key] !== typeof existing[key])
+                return false;
+            
+            if (typeof options[key] === 'object' && !objIsSubset(existing, options))
+                return false;
+            else if (options[key] !== existing[key])
+                return false;
+        }
+
+        return true;
+        
+    }
+
 }
 
 export { MongoDB };
\ No newline at end of file