Ensure update validators only call validators underneath single nested paths once

lib/helpers/updateValidators.js

@@ -147,6 +147,9 @@ module.exports = function(query, schema, castedDoc, options, callback) {
               return callback(null);
             }
           }
+          if (schemaPath.$isSingleNested) {
+            alreadyValidated.push(updates[i]);
+          }
 
           schemaPath.doValidate(v, function(err) {
             if (schemaPath.schema != null &&
@@ -246,4 +249,3 @@ module.exports = function(query, schema, castedDoc, options, callback) {
     };
   }
 };
-

test/model.updateOne.test.js

@@ -3143,6 +3143,52 @@ describe('model: updateOne: ', function() {
     assert.equal(r2.testArray[0].key, 'Type2');
     assert.equal(r2.testArray[0].field2, field2update);
   });
+
+  it('only calls validators under single nested subdocs once (gh-15436)', async function() {
+    let validateDetailsCalls = 0;
+    let validateNameCalls = 0;
+
+    const kittySchema = new mongoose.Schema({
+      informations: {
+        type: {
+          details: {
+            validate: function() {
+              validateDetailsCalls++;
+              return true;
+            },
+            type: {
+              name: {
+                type: String,
+                validate: function() {
+                  validateNameCalls++;
+                  return true;
+                }
+              }
+            }
+          }
+        }
+      }
+    });
+
+    const Kitten = db.model('Test', kittySchema);
+
+    // Update the document with validation enabled
+    await Kitten.updateOne(
+      { _id: new mongoose.Types.ObjectId() },
+      {
+        informations: {
+          details: {
+            name: 'Zohra'
+          }
+        }
+      },
+      { runValidators: true }
+    );
+
+    // Assert that each validator was only called once
+    assert.equal(validateDetailsCalls, 1);
+    assert.equal(validateNameCalls, 1);
+  });
 });
 
 async function delay(ms) {

test/types/models.test.ts

@@ -1010,3 +1010,26 @@ async function gh15369() {
     throw error;
   }
 }
+
+async function gh15437() {
+  interface Person {
+    name: string;
+    age: number;
+    address: string;
+  }
+
+  const schema = new mongoose.Schema({
+    name: String,
+    age: Number,
+    address: String
+  });
+  const PersonModel = model<Person>('Person', schema);
+
+  const data = { name: 'John Doe', age: 30, address: '123 Main St' };
+
+  // Test hydrating with string projection
+  const doc1 = PersonModel.hydrate(data, 'name age');
+  expectType<string>(doc1.name);
+  expectType<number>(doc1.age);
+  expectAssignable<undefined | null | string>(doc1.address);
+}

types/models.d.ts

@@ -482,7 +482,7 @@ declare module 'mongoose' {
      * Shortcut for creating a new Document from existing raw data, pre-saved in the DB.
      * The document returned has no paths marked as modified initially.
      */
-    hydrate(obj: any, projection?: AnyObject, options?: HydrateOptions): THydratedDocumentType;
+    hydrate(obj: any, projection?: ProjectionType<TRawDocType>, options?: HydrateOptions): THydratedDocumentType;
 
     /**
      * This function is responsible for building [indexes](https://www.mongodb.com/docs/manual/indexes/),