From 01b182e7d68b8a9907f5926178afe95a4c2e1d79 Mon Sep 17 00:00:00 2001
From: Valeri Karpov <val@karpov.io>
Date: Thu, 1 Aug 2019 12:17:47 -0400
Subject: [PATCH] refactor: handle arrays underneath mixed paths for #6405

---
 lib/document.js                   | 11 ++++++-
 lib/helpers/updateValidators.js   |  2 +-
 lib/schema.js                     | 49 ++++++++++++++++++++++++-------
 test/document.test.js             |  2 +-
 test/es-next/virtuals.test.es6.js |  4 +++
 5 files changed, 54 insertions(+), 14 deletions(-)

diff --git a/lib/document.js b/lib/document.js
index 5fee1744249..327627500fe 100644
--- a/lib/document.js
+++ b/lib/document.js
@@ -1346,7 +1346,16 @@ Document.prototype.get = function(path, type, options) {
     adhoc = this.schema.interpretAsType(path, type, this.schema.options);
   }
 
-  const schema = this.$__path(path) || this.schema.virtualpath(path);
+  let schema = this.$__path(path);
+  if (schema == null) {
+    schema = this.schema.virtualpath(path);
+  }
+  if (schema instanceof MixedSchema) {
+    const virtual = this.schema.virtualpath(path);
+    if (virtual != null) {
+      schema = virtual;
+    }
+  }
   const pieces = path.split('.');
   let obj = this._doc;
 
diff --git a/lib/helpers/updateValidators.js b/lib/helpers/updateValidators.js
index a8618961432..4eeecbb2c5e 100644
--- a/lib/helpers/updateValidators.js
+++ b/lib/helpers/updateValidators.js
@@ -100,7 +100,7 @@ module.exports = function(query, schema, castedDoc, options) {
 
     // gh-4305: `_getSchema()` will report all sub-fields of a 'Mixed' path
     // as 'Mixed', so avoid double validating them.
-    if (schemaPath instanceof Mixed && schemaPath.$fullPath !== updates[i]) {
+    if (schemaPath instanceof Mixed && schemaPath.path !== updates[i]) {
       return;
     }
 
diff --git a/lib/schema.js b/lib/schema.js
index b036c1d8165..ec310157dcb 100644
--- a/lib/schema.js
+++ b/lib/schema.js
@@ -543,16 +543,11 @@ warnings.increment = '`increment` should not be used as a schema path name ' +
 
 Schema.prototype.path = function(path, obj) {
   // Convert to '.$' to check subpaths re: gh-6405
-  const cleanPath = path.replace(/\.\d+\./g, '.$.').replace(/\.\d+$/, '.$');
+  const cleanPath = _pathToPositionalSyntax(path);
   if (obj === undefined) {
-    if (this.paths.hasOwnProperty(path)) {
-      return this.paths[path];
-    }
-    if (this.subpaths.hasOwnProperty(cleanPath)) {
-      return this.subpaths[cleanPath];
-    }
-    if (this.singleNestedPaths.hasOwnProperty(cleanPath)) {
-      return this.singleNestedPaths[cleanPath];
+    let schematype = _getPath(this, path, cleanPath);
+    if (schematype != null) {
+      return schematype;
     }
 
     // Look for maps
@@ -561,6 +556,12 @@ Schema.prototype.path = function(path, obj) {
       return mapPath;
     }
 
+    // Look if a parent of this path is mixed
+    schematype = this.hasMixedParent(cleanPath);
+    if (schematype != null) {
+      return schematype;
+    }
+
     // subpaths?
     return /\.\d+\.?.*$/.test(path)
       ? getPositionalPath(this, path)
@@ -705,6 +706,32 @@ function gatherChildSchemas(schema) {
   return childSchemas;
 }
 
+/*!
+ * ignore
+ */
+
+function _getPath(schema, path, cleanPath) {
+  if (schema.paths.hasOwnProperty(path)) {
+    return schema.paths[path];
+  }
+  if (schema.subpaths.hasOwnProperty(cleanPath)) {
+    return schema.subpaths[cleanPath];
+  }
+  if (schema.singleNestedPaths.hasOwnProperty(cleanPath)) {
+    return schema.singleNestedPaths[cleanPath];
+  }
+
+  return null;
+}
+
+/*!
+ * ignore
+ */
+
+function _pathToPositionalSyntax(path) {
+  return path.replace(/\.\d+\./g, '.$.').replace(/\.\d+$/, '.$');
+}
+
 /*!
  * ignore
  */
@@ -1014,11 +1041,11 @@ Schema.prototype.hasMixedParent = function(path) {
     path = i > 0 ? path + '.' + subpaths[i] : subpaths[i];
     if (path in this.paths &&
         this.paths[path] instanceof MongooseTypes.Mixed) {
-      return true;
+      return this.paths[path];
     }
   }
 
-  return false;
+  return null;
 };
 
 /**
diff --git a/test/document.test.js b/test/document.test.js
index fae94375437..ce7d79df7f1 100644
--- a/test/document.test.js
+++ b/test/document.test.js
@@ -7860,7 +7860,7 @@ describe('document', function() {
     });
   });
 
-  it('allows saving an unchanged document if populated path is null (gh-8018)', function() {
+  it('allows saving an unchanged document if required populated path is null (gh-8018)', function() {
     const schema = Schema({ test: String });
     const schema2 = Schema({
       keyToPopulate: {
diff --git a/test/es-next/virtuals.test.es6.js b/test/es-next/virtuals.test.es6.js
index 959f78496b4..03bc01b72c2 100644
--- a/test/es-next/virtuals.test.es6.js
+++ b/test/es-next/virtuals.test.es6.js
@@ -158,6 +158,10 @@ describe('Virtuals', function() {
     const User = mongoose.model('User', userSchema);
     const BlogPost = mongoose.model('BlogPost', blogPostSchema);
 
+    // acquit:ignore:start
+    await BlogPost.deleteMany({});
+    await User.deleteMany({});
+    // acquit:ignore:end
     await BlogPost.create({ title: 'Introduction to Mongoose', authorId: 1 });
     await User.create({ _id: 1, email: 'test@gmail.com' });