fix: improve error handling and refactor to use async/await

lib/plugins/saveSubdocs.js

@@ -36,25 +36,26 @@ module.exports = function saveSubdocs(schema) {
     });
   }, null, unshift);
 
-  schema.s.hooks.post('save', function saveSubdocsPostDeleteOne(doc, next) {
+  schema.s.hooks.post('save', async function saveSubdocsPostDeleteOne() {
     const removedSubdocs = this.$__.removedSubdocs;
     if (!removedSubdocs || !removedSubdocs.length) {
-      return next();
+      return;
     }
 
-    each(removedSubdocs, function(subdoc, cb) {
-      subdoc.$__schema.s.hooks.execPost('deleteOne', subdoc, [subdoc], function(err) {
-        cb(err);
-      });
-    }, (error) => {
-      this.$__.removedSubdocs = null;
-      if (error) {
-        return this.$__schema.s.hooks.execPost('deleteOne:error', this, [this], { error: error }, function(error) {
-          next(error);
+    const promises = [];
+    for (const subdoc of removedSubdocs) {
+      promises.push(new Promise((resolve, reject) => {
+        subdoc.$__schema.s.hooks.execPost('deleteOne', subdoc, [subdoc], function(err) {
+          if (err) {
+            return reject(err);
+          }
+          resolve();
         });
-      }
-      next();
-    });
+      }));
+    }
+
+    this.$__.removedSubdocs = null;
+    await Promise.all(promises);
   });
 
   schema.s.hooks.post('save', function saveSubdocsPostSave(doc, next) {

test/document.test.js

@@ -13544,6 +13544,7 @@ describe('document', function() {
       preDeleteOne: 0,
       postDeleteOne: 0
     };
+    let postDeleteOneError = null;
     ChildSchema.pre('save', function(next) {
       ++called.preSave;
       next();
@@ -13558,7 +13559,7 @@ describe('document', function() {
     });
     ChildSchema.post('deleteOne', { document: true, query: false }, function(subdoc, next) {
       ++called.postDeleteOne;
-      next();
+      next(postDeleteOneError);
     });
     const ParentSchema = new Schema({ name: String, children: [ChildSchema] });
     const ParentModel = db.model('Parent', ParentSchema);
@@ -13590,6 +13591,14 @@ describe('document', function() {
       preDeleteOne: 1,
       postDeleteOne: 1
     });
+
+    postDeleteOneError = new Error('Test error in post deleteOne hook');
+    const child3 = doc.children[1];
+    child3.deleteOne();
+    await assert.rejects(
+      () => doc.save(),
+      /Test error in post deleteOne hook/
+    );
   });
 });