basic support for storing blobs in tables using $binary

src/client/deserialize.ts

@@ -2,7 +2,36 @@ import { EJSON, ObjectId } from 'bson';
 import mongoose from 'mongoose';
 
 export function deserialize(data: Record<string, any>): Record<string, any> {
-    return data != null ? deserializeObjectIds(EJSON.deserialize(data)) : data;
+    return data != null ? deserializeObjectIds(EJSON.deserialize(deserializeBuffers(data))) : data;
+}
+
+function deserializeBuffers(data: Record<string, any>): Record<string, any> {
+    if (data == null) {
+        return data;
+    }
+    if (Array.isArray(data)) {
+        for (let i = 0; i < data.length; ++i) {
+            if (data[i] == null) {
+                continue;
+            }
+            if (typeof data[i].$binary === 'string') {
+                data[i] = Buffer.from(data[i].$binary, 'base64');
+            } else if (typeof data[i] === 'object') {
+                deserializeBuffers(data[i]);
+            }
+        }
+    }
+    for (const key of Object.keys(data)) {
+        if (data[key] == null) {
+            continue;
+        }
+        if (typeof data[key].$binary === 'string') {
+            data[key] = Buffer.from(data[key].$binary, 'base64');
+        } else if (typeof data[key] === 'object') {
+            deserializeBuffers(data[key]);
+        }
+    }
+    return data;
 }
 
 function deserializeObjectIds(data: Record<string, any>): Record<string, any> {

src/client/httpClient.ts

@@ -166,7 +166,8 @@ class HTTP2Session {
                 ':method': 'POST',
                 token
             });
-            req.write(serialize(body), 'utf8');
+            const dataStr = serialize(body);
+            req.write(dataStr, 'utf8');
             req.end();
 
             let status = 0;

src/client/serialize.ts

@@ -54,6 +54,8 @@ function serializeValue(value: any): any {
             //UUID handling. Subtype 03 or 04 is UUID. Refer spec : https://bsonspec.org/spec.html
             return Buffer.from(value.$binary.base64, 'base64').toString('hex')
                 .replace(/(.{8})(.{4})(.{4})(.{4})(.{12})/, '$1-$2-$3-$4-$5');
+        } else if (value.$binary) {
+            return { $binary: value.$binary.base64 };
         }
         //Date handling
         else if (value.$date) {

tests/driver/api.test.ts

@@ -728,6 +728,11 @@ describe('Mongoose Model API level tests', async () => {
                 featureFlags: ['Feature-Flag-tables']
             };
             await mongoose.connect(testClient!.uri, options as mongoose.ConnectOptions);
+            await mongoose.connection.db.runCommand({
+                dropTable: {
+                    name: 'bots'
+                }
+            });
             const res = await mongoose.connection.db.runCommand({
                 createTable: {
                     name: 'bots',
@@ -739,12 +744,24 @@ describe('Mongoose Model API level tests', async () => {
                             },
                             name: {
                                 type: 'text'
+                            },
+                            buf: {
+                                type: 'blob'
                             }
                         }
                     }
                 }
             });
             assert.ok(res.status.ok);
+
+            const schema = new mongoose.Schema({ buf: Buffer }, { versionKey: false });
+            const TestModel = mongoose.model('Test', schema, 'bots');
+            const doc = new TestModel({ buf: Buffer.from('hello world') });
+            await doc.save();
+
+            const fromDb = await TestModel.findOne();
+            assert.equal(fromDb.buf.toString('utf8'), 'hello world');
+
             await mongoose.disconnect();
         });
     });