From fcb0101cf63372df1cdf08aee2228f091921cd47 Mon Sep 17 00:00:00 2001
From: nodkz <pavel.chertorogov@gmail.com>
Date: Sun, 21 Jan 2018 21:10:58 +0600
Subject: [PATCH] fix: old counter records without `groupingField`

---
 src/__tests__/index-test.js | 46 ++++++++++++++++++++++++++++++++++++-
 src/index.js                | 27 +++++++++++++++++++---
 2 files changed, 69 insertions(+), 4 deletions(-)

diff --git a/src/__tests__/index-test.js b/src/__tests__/index-test.js
index 8f3d1da..d4dbb68 100644
--- a/src/__tests__/index-test.js
+++ b/src/__tests__/index-test.js
@@ -352,7 +352,7 @@ describe('mongoose-auto-increment', () => {
 
   it('with string field and output filter increment the counter value only once', async () => {
     const userSchema = new mongoose.Schema({
-      orderNumber: String,
+      orderNumber: Number,
       name: String,
       dept: String,
     });
@@ -372,4 +372,48 @@ describe('mongoose-auto-increment', () => {
     await user1.save();
     expect(user1.orderNumber).toBe(initialId);
   });
+
+  it('should fix old counter record without `groupingField`', async () => {
+    const _id = new mongoose.Types.ObjectId('100000000000000000000000');
+    const icCollectoion = connection.collection('identitycounters');
+    await icCollectoion.ensureIndex(
+      {
+        field: 1,
+        groupingField: 1,
+        model: 1,
+      },
+      {
+        unique: true,
+      }
+    );
+    await icCollectoion.insert({
+      _id,
+      model: 'User',
+      field: 'orderNumber',
+      count: 79,
+    });
+
+    expect(await icCollectoion.find().toArray()).toEqual([
+      { _id, count: 79, field: 'orderNumber', model: 'User' },
+    ]);
+
+    const userSchema = new mongoose.Schema({
+      orderNumber: Number,
+      name: String,
+      dept: String,
+    });
+    userSchema.plugin(autoIncrement, {
+      model: 'User',
+      field: 'orderNumber',
+    });
+    const User = connection.model('User', userSchema);
+    await User.ensureIndexes();
+
+    const user1 = new User({ name: 'Charlie', dept: 'Support' });
+    await user1.save();
+
+    expect(await icCollectoion.find().toArray()).toEqual([
+      { _id, count: 80, field: 'orderNumber', model: 'User', groupingField: '' },
+    ]);
+  });
 });
diff --git a/src/index.js b/src/index.js
index c096145..07218b4 100644
--- a/src/index.js
+++ b/src/index.js
@@ -54,6 +54,10 @@ export function initialize(): void {
   );
 }
 
+function isMongoDuplicateError(e: any): boolean {
+  return e.name === 'MongoError' && e.code === 11000;
+}
+
 // Initialize plugin by creating counter collection in database.
 function initIdentityCounter(connection: MongooseConnection): IdentityCounterModel {
   let identityCounter;
@@ -76,20 +80,37 @@ async function createCounterIfNotExist(
   settings: AutoIncSettings,
   doc: MongooseDocument
 ): Promise<IdentityCounterDoc> {
+  const groupingField = doc.get(settings.groupingField) || '';
+
   let existedCounter: IdentityCounterDoc = (await IC.findOne({
     model: settings.model,
     field: settings.field,
-    groupingField: doc.get(settings.groupingField) || '',
+    groupingField,
   }).exec(): any);
 
+  // Check old record without `groupingField`,
+  // so let fix this record by adding this field
+  if (!existedCounter) {
+    existedCounter = (await IC.findOne({
+      model: settings.model,
+      field: settings.field,
+      groupingField: { $exists: false },
+    }): any);
+    if (existedCounter) {
+      existedCounter.groupingField = '';
+      await existedCounter.save();
+    }
+  }
+
   if (!existedCounter) {
     // If no counter exists then create one and save it.
     existedCounter = (new IC({
       model: settings.model,
       field: settings.field,
-      groupingField: doc.get(settings.groupingField) || '',
+      groupingField,
       count: settings.startAt - settings.incrementBy,
     }): any);
+
     await existedCounter.save();
   }
 
@@ -158,7 +179,7 @@ async function preSave(
 
     next();
   } catch (err) {
-    if (err.name === 'MongoError' && err.code === 11000) {
+    if (isMongoDuplicateError(err)) {
       setTimeout(() => preSave(IC, settings, doc, next), 5);
     } else {
       next(err);