feat: Add information about, db collection and index name on duplicate value error

spec/schemas.spec.js

@@ -3835,6 +3835,7 @@ describe('schemas', () => {
         .then(done.fail)
         .catch(error => {
           expect(error.code).toEqual(Parse.Error.DUPLICATE_VALUE);
+          expect(error.message).toEqual('A duplicate value for a field with unique values was provided. Duplicate index: code_1 on collection test_UniqueIndexClass in db parseServerMongoAdapterTestDatabase')
           done();
         });
     });

src/Adapters/Storage/Mongo/MongoStorageAdapter.js

@@ -26,6 +26,29 @@ const ReadPreference = mongodb.ReadPreference;
 
 const MongoSchemaCollectionName = '_SCHEMA';
 
+
+// If we get a unique index error from mongo, try to parse it. If successful, return it.
+const mongoUniqueIndexErrorFormatter = (message) => {
+  /**
+   * Sample error message that we are getting from mongo
+   * 'Plan executor error during findAndModify :: caused by :: E11000 duplicate key error collection: parseServerMongoAdapterTestDatabase.test_UniqueIndexClass index: code_1 dup key: { code: 2 }'
+   */
+  const regex = /collection:\s*([\w-]+)\.([\w-]+)\s+index:\s*([\w-]+)/;
+
+  const match = message.match(regex);
+
+  if (match) {
+    const dbName = match[1];
+    const collectionName = match[2];
+    const indexName = match[3];
+    // Adding extra starting space to make it more readable.
+    return ` Duplicate index: ${indexName} on collection ${collectionName} in db ${dbName}`;
+  }
+
+  // Return nothing
+  return '';
+}
+
 const storageAdapterAllCollections = mongoAdapter => {
   return mongoAdapter
     .connect()
@@ -490,7 +513,7 @@ export class MongoStorageAdapter implements StorageAdapter {
           // Duplicate value
           const err = new Parse.Error(
             Parse.Error.DUPLICATE_VALUE,
-            'A duplicate value for a field with unique values was provided'
+            `A duplicate value for a field with unique values was provided.${mongoUniqueIndexErrorFormatter(error.message)}`
           );
           err.underlyingError = error;
           if (error.message) {
@@ -575,7 +598,7 @@ export class MongoStorageAdapter implements StorageAdapter {
         if (error.code === 11000) {
           throw new Parse.Error(
             Parse.Error.DUPLICATE_VALUE,
-            'A duplicate value for a field with unique values was provided'
+            `A duplicate value for a field with unique values was provided.${mongoUniqueIndexErrorFormatter(error.message)}`
           );
         }
         throw error;