fix(schema): load child class getter for virtuals instead of base cla…

…ss when using `loadClass()`

Fix #9975

lib/schema.js

@@ -1900,7 +1900,7 @@ Schema.prototype.loadClass = function(model, virtualsOnly) {
     return this;
   }
 
-  this.loadClass(Object.getPrototypeOf(model));
+  this.loadClass(Object.getPrototypeOf(model), virtualsOnly);
 
   // Add static methods
   if (!virtualsOnly) {
@@ -1927,9 +1927,15 @@ Schema.prototype.loadClass = function(model, virtualsOnly) {
       }
     }
     if (typeof method.get === 'function') {
+      if (this.virtuals[name]) {
+        this.virtuals[name].getters = [];
+      }
       this.virtual(name).get(method.get);
     }
     if (typeof method.set === 'function') {
+      if (this.virtuals[name]) {
+        this.virtuals[name].setters = [];
+      }
       this.virtual(name).set(method.set);
     }
   }, this);

test/schema.test.js

@@ -2566,4 +2566,22 @@ describe('schema', function() {
     assert.equal(schema.path('tags').caster.instance, 'String');
     assert.equal(schema.path('subdocs').casterConstructor.schema.path('name').instance, 'String');
   });
+
+  it('handles loadClass with inheritted getters (gh-9975)', function() {
+    class User {
+      get displayAs() {
+        return null;
+      }
+    }
+
+    class TechnicalUser extends User {
+      get displayAs() {
+        return this.name;
+      }
+    }
+
+    const schema = new Schema({ name: String }).loadClass(TechnicalUser);
+
+    assert.equal(schema.virtuals.displayAs.applyGetters(null, { name: 'test' }), 'test');
+  });
 });