Bugfix: Return _id as ObjectId from cache

src/extend-aggregate.js

@@ -1,6 +1,7 @@
 'use strict';
 
 const generateKey = require('./generate-key');
+const recoverObjectId = require('./recover-objectid');
 let hasBeenExtended = false;
 
 module.exports = function(mongoose, cache) {
@@ -28,7 +29,9 @@ module.exports = function(mongoose, cache) {
 
       return new Promise((resolve, reject) => {
         cache.get(key, (err, cachedResults) => { //eslint-disable-line handle-callback-err
-          if (cachedResults) {
+          if (cachedResults != null) {
+            cachedResults = recoverObjectId(mongoose, cachedResults);
+
             callback(null, cachedResults);
             return resolve(cachedResults);
           }

src/extend-query.js

@@ -1,6 +1,7 @@
 'use strict';
 
 const generateKey = require('./generate-key');
+const recoverObjectId = require('./recover-objectid');
 
 module.exports = function(mongoose, cache) {
   const exec = mongoose.Query.prototype.exec;
@@ -34,6 +35,8 @@ module.exports = function(mongoose, cache) {
             cachedResults = Array.isArray(cachedResults) ?
               cachedResults.map(hydrateModel(constructor)) :
               hydrateModel(constructor)(cachedResults);
+          } else {
+            cachedResults = recoverObjectId(mongoose, cachedResults);
           }
 
           callback(null, cachedResults);

src/recover-objectid.js

@@ -0,0 +1,25 @@
+'use strict';
+
+module.exports = function(mongoose, cachedResults) {
+  if (!Array.isArray(cachedResults)) {
+    return recoverObjectId(mongoose, cachedResults);
+  }
+
+  const recoveredResult = [];
+
+  for (const doc of cachedResults) {
+    recoveredResult.push(recoverObjectId(mongoose, doc));
+  }
+
+  return recoveredResult;
+};
+
+function recoverObjectId(mongoose, doc) {
+  if (!doc._id) {
+    return doc;
+  }
+
+  // eslint-disable-next-line new-cap
+  doc._id = mongoose.Types.ObjectId(doc._id);
+  return doc;
+}

test/index.js

@@ -351,6 +351,30 @@ describe('cachegoose', () => {
     const diffSort = await getAllSorted({ num: -1 });
     diffSort.length.should.equal(20);
   });
+
+  it('should return similar _id in cached array result for lean', async () => {
+    const originalRes = await getAllLean(60);
+    const cachedRes = await getAllLean(60);
+    const originalConstructor = originalRes[0]._id.constructor.name.should;
+    const cachedConstructor = cachedRes[0]._id.constructor.name.should;
+    originalConstructor.should.deepEqual(cachedConstructor);
+  });
+
+  it('should return similar _id in one cached result for lean', async () => {
+    const originalRes = await getOneLean(60);
+    const cachedRes = await getOneLean(60);
+    const originalConstructor = originalRes._id.constructor.name.should;
+    const cachedConstructor = cachedRes._id.constructor.name.should;
+    originalConstructor.should.deepEqual(cachedConstructor);
+  });
+
+  it('should return similar _id in cached array result for aggregate', async () => {
+    const originalRes = await aggregateAll(60);
+    const cachedRes = await aggregateAll(60);
+    const originalConstructor = originalRes[0]._id.constructor.name.should;
+    const cachedConstructor = cachedRes[0]._id.constructor.name.should;
+    originalConstructor.should.deepEqual(cachedConstructor);
+  });
 });
 
 function getAll(ttl, cb) {
@@ -373,6 +397,10 @@ function getOne(ttl, cb) {
   return Record.findOne({ num: { $gt: 2 } }).cache(ttl).exec(cb);
 }
 
+function getOneLean(ttl, cb) {
+  return Record.findOne({ num: { $gt: 2 } }).lean().cache(ttl).exec(cb);
+}
+
 function getWithSkip(skip, ttl, cb) {
   return Record.find({}).skip(skip).cache(ttl).exec(cb);
 }
@@ -432,6 +460,14 @@ function aggregate(ttl, cb) {
     .exec(cb);
 }
 
+function aggregateAll(ttl, cb) {
+  return Record.aggregate([
+    { $match: {} },
+  ])
+    .cache(ttl)
+    .exec(cb);
+}
+
 function generate(amount) {
   const records = [];
   let count = 0;