Turao / go-ddd

DDD, CQRS, and Event Sourcing concepts using Go

go-ddd

Kind of trying to create a Project Manager (e.g. Jira)...

What I want to practice:

• Clean Architecture (e.g. domain, application, infrastructure layers)
• DDD (e.g. Aggregates, Domain Events, ...)
• CQRS (e.g. Read / Write models)
  • Have some projections to list tasks by project, tasks by user, and do some full-text searching based on the task description
• Event Sourcing
  • Billing: tracks how many tasks have been assigned and completed by each user so we can pay them later.
    • Domain Events are replayed every time there's an UPDATE-like Command (e.g. AddTaskToUser)
    • Add Snapshot behavior to cache the AggregateRoot's state and avoid replaying ALL events on every update command...
      • Doing that right now...
• Other:
  • Table-Driven tests (see users/aggregate_test.go)

Contexts

User

• Commands:
  • RegisterUsed
• Queries:
  • ListUsers
• Events:
  • UserRegistered

Project

• Commands:
  • CreateProject
  • UpdateProject
  • DeleteProject
• Queries:
  • FindProject (by ID)
  • ListProjects
• Events:
  • ProjectCreated
  • ProjectUpdated
  • ProjectDeleted

Task

• Commands:
  • CreateTask
  • AssignToUser
  • UnassignUser
  • UpdateTitle
  • UpdateDescription
  • UpdateStatus
• Queries:
  • TasksByProject
  • TasksByAssignedUser
• Events:
  • TaskCreated
  • TaskAssigned
  • TaskUnassigned
  • TitleUpdated
  • DescriptionUpdated
  • StatusUpdated

Tasks should likely be part of Project's context (Projects often don't have that many tasks)... but (1) I don't care about strong consistency between Project and Task really that much (2) let's pretend users will create a lot of tasks for each project, so we need to move the collection to its own bounded context...

Billing

• Commands:
  • CreateAccount
  • AddTaskToUser
  • RemoveTaskFromUser
• Queries:
  • AccountDetails (TODO)
    • get information like invoice id + number of tasks concluded + what we need to pay for this user
• Events:
  • AccountCreated
  • TaskAdded
    • whenever an user is assigned to a task, we add it into the User's Account Invoice
  • TaskRemoved
    • whenever an user is unassigned from a task, we remove it from the User's Account Invoice

Will listen to:

• UserRegistered
• TaskAssigned
• TaskUnassigned
• StatusUpdated