Technical Task (Software Engineer)

Take as long as you need - as a guideline we would expect it to take up to 60 minutes.

Introduction

Glean lets you record audio and take notes in an Event. A simplified version of the Event record is as follows:

+-------------------------------+
|             Event             |
+-------------------------------+
| name  | Text                  | 
| notes | A collection of Notes | 
+-------------------------------+

A Note contains some text, and is associated with a timestamp - an offset in milliseconds from the start of the recording:

+-----------------------------+
|            Note             |
+-----------------------------+
| id        | Unique ID       |
| timestamp | Millis offset   | 
| text      | Text            | 
+-----------------------------+

The Event is created in a frontend client, and can be saved to the backend and synced to other clients. This brings the possibility of two different clients (e.g. the web application and a mobile app) making divergent changes to the same Event and having to resolve the differences.

Task

Implement code to handle two input Events, one remote and one local, outputting a combined Event. For example, a function with signature:

resolveEvents(remote: Event, local: Event): Event

Where:

• remote: the Event that was last uploaded to the backend.
• local: the copy of the Event with local changes.
• return: resolved version of the Event, combining the information from both inputs.

Requirements / assumptions:

• Notes that have the same ID in both Events are considered to be the same Note, and need conflict resolution. Otherwise retain Notes from both Events.
• Conflicting text data in both the Event and Note should be combined with a slash (see the example).
• Conflicting timestamps in a Note should be resolved by using the timestamp from the remote version.
• All input data is guaranteed not to be null.
• Write unit tests that cover the logic of your solution.

Example

The examples below are given in JSON-like syntax, but it's not necessary to implement JSON serialisation/deserialisation.

Local Event

{
  name: 'Name 1',
  notes: [
    { id: 1, timestamp: 3200, text: 'A' },
    { id: 2, timestamp: 5600, text: 'C' }
  ]
}

Remote Event

{
  name: 'Name 2',
  notes: [
   { id: 1, timestamp: 2400, text: 'B' }
  ]
}

Resolved Event

{
  name: 'Name 1 / Name 2',
  notes: [
   { id: 1, timestamp: 2400, text: 'A / B' },
   { id: 2, timestamp: 5600, text: 'C' }
  ]
}

Submit your solution

Please push your solution to a branch and open a PR once you are finished. Get in touch to let us know you are done and we'll aim to review your code within 2 working days.