From b63255262cfc911979139103757ce4d578201488 Mon Sep 17 00:00:00 2001
From: Nathan Knight <knathanknight@gmail.com>
Date: Tue, 19 Mar 2024 09:31:46 -0400
Subject: [PATCH] Fixed handling discriminators in nested document arrays

---
 index.js           |  8 +++++++-
 test/index.test.js | 38 ++++++++++++++++++++++++++++++++++++--
 2 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/index.js b/index.js
index eaf2abb..e7df627 100644
--- a/index.js
+++ b/index.js
@@ -74,7 +74,7 @@ function getSchemaForDoc(schema, res) {
   const discriminatorValue = res[schema.discriminatorMapping.key];
   let childSchema = undefined;
   for (const name of Object.keys(schema.discriminators)) {
-    const matchValue = schema.discriminators[name].discriminatorMapping.value || modelName;
+    const matchValue = schema.discriminators[name].discriminatorMapping.value;
     if (matchValue === discriminatorValue) {
       childSchema = schema.discriminators[name];
       break;
@@ -91,7 +91,13 @@ function applyGettersToDoc(schema, doc, fields, prefix) {
   if (Array.isArray(doc)) {
     for (let i = 0; i < doc.length; ++i) {
       const currentDoc = doc[i];
+      // If the current doc is null/undefined, there's nothing to do
       if (currentDoc == null) continue;
+      // If it is a nested array, apply getters to each subdocument (otherwise it would attempt to apply getters to the array itself)
+      if (Array.isArray(currentDoc)) {
+        applyGettersToDoc.call(this, schema, currentDoc, fields, prefix);
+        continue;
+      }
       const schemaForDoc = getSchemaForDoc(schema, currentDoc);
       applyGettersToDoc.call(this, schemaForDoc, currentDoc, fields, prefix);
     }
diff --git a/test/index.test.js b/test/index.test.js
index d163e46..bcf3f5a 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -249,7 +249,7 @@ describe('mongoose-lean-getters', function() {
 
     assert.equal(docs[0].url, 'https://www.test.com discriminator field');
   });
-  
+
   it('should call getters on schemas with discriminator using explicit value', async function() {
     const options = { discriminatorKey: 'kind' };
 
@@ -304,7 +304,41 @@ describe('mongoose-lean-getters', function() {
 
     assert.equal(docs[0].events[0].url, 'https://www.test.com discriminator field');
   });
-    
+
+  it('should work on schemas with discriminators in nested arrays', async function() {
+    const options = { discriminatorKey: 'kind' };
+
+    const eventSchema = new mongoose.Schema({ time: Date }, options);
+    const clickedLinkSchema = new mongoose.Schema({
+      url: { type: String, get: v => v + ' discriminator field' }
+    });
+    eventSchema.discriminator('VisitedPage', clickedLinkSchema);
+
+    const eventGroupSchema = new mongoose.Schema({
+      events: [eventSchema]
+    });
+
+    const eventListSchema = new mongoose.Schema({
+      eventGroups: [eventGroupSchema],
+    });
+    eventListSchema.plugin(mongooseLeanGetters);
+    const EventGroupList = mongoose.model('EventGroupList', eventListSchema);
+
+    await EventGroupList.deleteMany({});
+    await EventGroupList.create({
+      eventGroups: [{
+        events: [{
+          kind: 'VisitedPage',
+          url: 'https://www.test.com'
+        }],
+      }],
+    });
+
+    const docs = await EventGroupList.find().lean({ getters: true });
+
+    assert.equal(docs[0].eventGroups[0].events[0].url, 'https://www.test.com discriminator field');
+  });
+
   it('should call getters on arrays (gh-30)', async function() {
     function upper(value) {
       return value.toUpperCase();