From 9a99bd59a9fbcfc71072ec6771d663cb547dc64a Mon Sep 17 00:00:00 2001
From: Daniel Diaz <39510674+IslandRhythms@users.noreply.github.com>
Date: Mon, 24 Apr 2023 17:13:37 -0400
Subject: [PATCH] feat: implement `createCollections()`

---
 lib/connection.js                   | 37 +++++++++++++++++++++++++++++
 lib/error/createCollectionsError.js | 26 ++++++++++++++++++++
 lib/model.js                        |  2 +-
 test/connection.test.js             | 18 ++++++++++++++
 4 files changed, 82 insertions(+), 1 deletion(-)
 create mode 100644 lib/error/createCollectionsError.js

diff --git a/lib/connection.js b/lib/connection.js
index a2769614de5..a7d93526815 100644
--- a/lib/connection.js
+++ b/lib/connection.js
@@ -20,6 +20,7 @@ const mongodb = require('mongodb');
 const pkg = require('../package.json');
 const utils = require('./utils');
 const processConnectionOptions = require('./helpers/processConnectionOptions');
+const CreateCollectionsError = require('./error/createCollectionsError');
 
 const arrayAtomicsSymbol = require('./helpers/symbols').arrayAtomicsSymbol;
 const sessionNewDocuments = require('./helpers/symbols').sessionNewDocuments;
@@ -409,6 +410,42 @@ Connection.prototype.createCollection = async function createCollection(collecti
   return this.db.createCollection(collection, options);
 };
 
+/**
+ * Calls `createCollection()` on a models in a series.
+ *
+ * @method createCollections
+ * @param {Boolean} continueOnError When true, will continue to create collections and create a new error class for the collections that errored.
+ * @returns {Promise}
+ * @api public
+ */
+
+Connection.prototype.createCollections = async function createCollections(options = {}) {
+  const result = {};
+  const errorsMap = { };
+
+  const { continueOnError } = options;
+  delete options.continueOnError;
+  for (const model of Object.values(this.models)) {
+    try {
+      result[model.modelName] = await model.createCollection({});
+    } catch (err) {
+      if (!continueOnError) {
+        errorsMap[model.modelName] = err;
+        break;
+      } else {
+        result[model.modelName] = err;
+      }
+    }
+  }
+
+  if (!continueOnError && Object.keys(errorsMap).length) {
+    const message = Object.entries(errorsMap).map(([modelName, err]) => `${modelName}: ${err.message}`).join(', ');
+    const createCollectionsError = new CreateCollectionsError(message, errorsMap);
+    throw createCollectionsError;
+  }
+  return result;
+};
+
 /**
  * _Requires MongoDB >= 3.6.0._ Starts a [MongoDB session](https://www.mongodb.com/docs/manual/release-notes/3.6/#client-sessions)
  * for benefits like causal consistency, [retryable writes](https://www.mongodb.com/docs/manual/core/retryable-writes/),
diff --git a/lib/error/createCollectionsError.js b/lib/error/createCollectionsError.js
new file mode 100644
index 00000000000..4b69cae617e
--- /dev/null
+++ b/lib/error/createCollectionsError.js
@@ -0,0 +1,26 @@
+'use strict';
+
+const MongooseError = require('./mongooseError');
+
+/**
+ * createCollections Error constructor
+ *
+ * @param {String} message
+ * @param {String} errorsMap
+ * @inherits MongooseError
+ * @api private
+ */
+
+class CreateCollectionsError extends MongooseError {
+  constructor(message, errorsMap) {
+    super(message);
+    this.errors = errorsMap;
+  }
+}
+
+Object.defineProperty(CreateCollectionsError.prototype, 'name', {
+  value: 'CreateCollectionsError'
+});
+
+module.exports = CreateCollectionsError;
+
diff --git a/lib/model.js b/lib/model.js
index 5a09efac493..1e552398ddf 100644
--- a/lib/model.js
+++ b/lib/model.js
@@ -1405,11 +1405,11 @@ Model.createCollection = async function createCollection(options) {
   try {
     await this.db.createCollection(this.$__collection.collectionName, options);
   } catch (err) {
+
     if (err != null && (err.name !== 'MongoServerError' || err.code !== 48)) {
       throw err;
     }
   }
-
   return this.$__collection;
 };
 
diff --git a/test/connection.test.js b/test/connection.test.js
index a3689516d25..a2bf0a36af3 100644
--- a/test/connection.test.js
+++ b/test/connection.test.js
@@ -1529,4 +1529,22 @@ describe('connections:', function() {
     });
     assert.deepEqual(m.connections.length, 0);
   });
+  describe('createCollections()', function() {
+    it('should create collections for all models on the connection with the createCollections() function (gh-13300)', async function() {
+      const m = new mongoose.Mongoose();
+      const schema = new Schema({ name: String });
+      const A = m.model('gh13300A', schema, 'gh13300A');
+      const B = m.model('gh13300B', schema, 'gh13300B');
+      const C = m.model('gh13300C', schema, 'gh13300C');
+      await m.connect(start.uri);
+      await m.connection.createCollections();
+      const collections = await m.connection.db.listCollections().toArray();
+      assert.equal(collections.length, 3);
+      const collectionNames = collections.map(inner => Object.values(inner)[0]);
+      assert.equal(collectionNames.includes(A.modelName), true);
+      assert.equal(collectionNames.includes(B.modelName), true);
+      assert.equal(collectionNames.includes(C.modelName), true);
+      // currently cannot write test for continueOnError or errors in general.
+    });
+  });
 });