From 40cdb165f8747d4363294a33df00649bc3d51f95 Mon Sep 17 00:00:00 2001
From: Doguhan Okumus <douhan@gmail.com>
Date: Thu, 17 Jun 2021 20:33:54 +0300
Subject: [PATCH] .lean() with post-hook of .find and .findOne

---
 lib/mongoose-field-encryption.js | 54 +++++++++++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 1 deletion(-)

diff --git a/lib/mongoose-field-encryption.js b/lib/mongoose-field-encryption.js
index 40c6b4a..057f908 100644
--- a/lib/mongoose-field-encryption.js
+++ b/lib/mongoose-field-encryption.js
@@ -110,7 +110,13 @@ const fieldEncryption = function (schema, options) {
     }
   };
 
-  function getCompatitibleNextFunc(next) {
+  function getCompatitibleNextFunc(next, data) {
+    // ! For the post-hook for .find and .findOne data is the first argument,
+    // ! therefore checking for an object in the first argument resolves the 
+    // ! second argument to be next().
+    if (typeof next === "object" && typeof data === "function") {
+      return data;
+    }
     if (typeof next !== "function") {
       return defaultNext;
     }
@@ -122,6 +128,12 @@ const fieldEncryption = function (schema, options) {
     if (!data) {
       return next;
     }
+    // ! For the post-hook for .find and .findOne data is the first argument,
+    // ! therefore checking for an object in the first argument resolves the 
+    // ! data.
+    if (typeof next === "object") {
+      return next;
+    }
     return data;
   }
 
@@ -147,6 +159,13 @@ const fieldEncryption = function (schema, options) {
     }
   }
 
+  function decryptArrayFields(data, fields, secret) {
+    // ! looping through the array of data (multiple docs)
+    for (var obj of data) {
+      decryptFields(obj, fields, secret);
+    }
+  }
+
   function decryptFields(obj, fields, secret) {
     for (const field of fields) {
       const encryptedFieldName = encryptedFieldNamePrefix + field;
@@ -249,6 +268,39 @@ const fieldEncryption = function (schema, options) {
     }
   });
 
+  schema.post('find', function (_next, _data) {
+    const next = getCompatitibleNextFunc(_next, _data);
+    const data = getCompatibleData(_next, _data);
+    // ! checking if the request has lean()
+    if (this._mongooseOptions.lean) {
+      try {
+        // ! Data is being returned as an array. We need to loop through them.
+        decryptArrayFields(data, fieldsToEncrypt, secret());
+        next();
+      } catch (err) {
+        next(err);
+      }
+    } else {
+      next();
+    }
+  })
+
+  schema.post('findOne', function (_next, _data) {
+    const next = getCompatitibleNextFunc(_next, _data);
+    const data = getCompatibleData(_next, _data);
+    // ! checking if the request has lean()
+    if (this._mongooseOptions.lean) {
+      try {
+        decryptFields(data, fieldsToEncrypt, secret());
+        next();
+      } catch (err) {
+        next(err);
+      }
+    } else {
+      next();
+    }
+  })
+
   schema.pre("findOneAndUpdate", updateHook);
 
   schema.pre("update", updateHook);