feat(NODE-4419): UUID class deserialization (#509)

Author: aditi-khare-mongoDB

package-lock.json

@@ -41,6 +41,7 @@
     "@typescript-eslint/eslint-plugin": "^5.30.0",
     "@typescript-eslint/parser": "^5.30.0",
     "array-includes": "^3.1.3",
+    "array.prototype.flatmap": "^1.3.0",
     "benchmark": "^2.1.4",
     "chai": "^4.2.0",
     "eslint": "^8.18.0",

package.json

@@ -35,6 +35,8 @@ export interface DeserializeOptions {
   promoteBuffers?: boolean;
   /** when deserializing will promote BSON values to their Node.js closest equivalent types. */
   promoteValues?: boolean;
+  /** when deserializing will return UUID type, if promoteBuffers is also true then promoteUUIDs will take precedence and a buffer will not be returned  */
+  promoteUUIDs?: boolean;
   /** allow to specify if there what fields we wish to return as unserialized raw buffer. */
   fieldsAsRaw?: Document;
   /** return BSON regular expressions as BSONRegExp instances. */
@@ -135,6 +137,7 @@ function deserializeObject(
   const promoteBuffers = options['promoteBuffers'] == null ? false : options['promoteBuffers'];
   const promoteLongs = options['promoteLongs'] == null ? true : options['promoteLongs'];
   const promoteValues = options['promoteValues'] == null ? true : options['promoteValues'];
+  const promoteUUIDs = options.promoteUUIDs == null ? false : options.promoteUUIDs;
 
   // Ensures default validation option if none given
   const validation = options.validation == null ? { utf8: true } : options.validation;
@@ -413,7 +416,9 @@ function deserializeObject(
             throw new BSONError('Binary type with subtype 0x02 contains too short binary size');
         }
 
-        if (promoteBuffers && promoteValues) {
+        if (promoteUUIDs && subType === 4) {
+          value = new Binary(buffer.slice(index, index + binarySize), subType).toUUID();
+        } else if (promoteBuffers && promoteValues) {
           value = buffer.slice(index, index + binarySize);
         } else {
           value = new Binary(buffer.slice(index, index + binarySize), subType);
@@ -440,7 +445,9 @@ function deserializeObject(
           _buffer[i] = buffer[index + i];
         }
 
-        if (promoteBuffers && promoteValues) {
+        if (promoteUUIDs && subType === 4) {
+          value = new Binary(_buffer, subType).toUUID();
+        } else if (promoteBuffers && promoteValues) {
           value = _buffer;
         } else {
           value = new Binary(_buffer, subType);

src/parser/deserializer.ts

@@ -191,4 +191,65 @@ describe('UUID', () => {
       expect(plainUUIDSerialization).to.deep.equal(toBinarySerialization);
     });
   });
+
+  describe('deserialize', () => {
+    const originalUUID = new BSON.UUID();
+    const binaryUUID = originalUUID.toBinary();
+    const serializedUUID = BSON.serialize({ uuid: originalUUID.toBinary() });
+
+    it('should promoteUUIDs when flag is true', () => {
+      const { uuid: promotedUUID } = BSON.deserialize(serializedUUID, { promoteUUIDs: true });
+      expect(promotedUUID._bsontype).to.equal('UUID');
+      expect(promotedUUID).to.deep.equal(originalUUID);
+    });
+
+    it('should not promoteUUIDs when flag is false', () => {
+      const { uuid: unpromotedUUID } = BSON.deserialize(serializedUUID, { promoteUUIDs: false });
+      expect(unpromotedUUID._bsontype).to.equal('Binary');
+      expect(unpromotedUUID).to.deep.equal(binaryUUID);
+    });
+
+    it('should not promoteUUIDs when flag is omitted', () => {
+      const { uuid: omittedFlagUUID } = BSON.deserialize(serializedUUID);
+      expect(omittedFlagUUID._bsontype).to.equal('Binary');
+      expect(omittedFlagUUID).to.deep.equal(binaryUUID);
+    });
+
+    it('should throw BSONTypeError if _bsontype is not UUID and promoteUUIDs is true', () => {
+      const binaryVar = new Binary(Buffer.from('abc'), BSON_BINARY_SUBTYPE_UUID_NEW);
+      const serializedBinary = BSON.serialize({ d: binaryVar });
+      expect(() => {
+        BSON.deserialize(serializedBinary, { promoteUUIDs: true });
+      }).to.throw(BSONTypeError);
+    });
+
+    describe('promoteBuffers', () => {
+      const promoteUUIDValues = [true, false, undefined];
+      const promoteBufferValues = [true, false, undefined];
+
+      const testCases = promoteUUIDValues.flatMap(promoteUUIDs =>
+        promoteBufferValues.flatMap(promoteBuffers => ({
+          options: { promoteUUIDs, promoteBuffers },
+          // promoteBuffers: true returns a Buffer so _bsontype does not exist
+          outcome: promoteUUIDs ? 'UUID' : promoteBuffers ? undefined : 'Binary'
+        }))
+      );
+
+      for (const { options, outcome } of testCases) {
+        it(`should deserialize to ${outcome} type when promoteUUIDs is ${options.promoteUUIDs} and promoteBuffers is ${options.promoteBuffers}`, () => {
+          const { uuid } = BSON.deserialize(serializedUUID, options);
+          expect(uuid._bsontype).to.equal(outcome);
+          if (uuid._bsontype === 'UUID') {
+            expect(uuid.id).to.deep.equal(originalUUID.id);
+          } else if (uuid._bsontype === 'Binary') {
+            expect(uuid.buffer).to.deep.equal(originalUUID.id);
+          } else if (uuid._bsontype === undefined) {
+            expect(uuid).to.deep.equal(originalUUID.id);
+          } else {
+            expect.fail('Unexpected _bsontype');
+          }
+        });
+      }
+    });
+  });
 });

test/node/uuid_tests.js

@@ -10,6 +10,7 @@
 require('chai/register-expect');
 require('array-includes/auto');
 require('object.entries/auto');
+require('array.prototype.flatmap/auto');
 
 const BSON = require('../lib/bson');
 const { ensureBuffer } = require('../lib/ensure_buffer');