Use Case

As a driver engineer
I want to add BigInt64 deserialization to js-bson
So that users can make use of native JS BigInt64s

Unknowns

Acceptance Criteria

Implementation Requirements

• Ensure that when a BSON int64 value is encountered during deserialization, the output is controlled by the useBigInt64 flag. If true, then it should be converted to a BigInt64, otherwise, it will retain the current behaviour of returning a pair of BSON.Longs

Testing Requirements

• Unit tests that directly inspect binary output of BSON.serialize when passed BigInt64 values and compares them to known cases
• Check that flag supersedes promoteLongs and promoteValues effects on serialization of Longs.
• Ensure that flag defaults to false
• Ensure that when flag is false, previously implemented behaviour is unchanged

Documentation Requirements

• Update js-bson README to explain usage of useBigInt64 flag