RFC: Pull Requests

[dirkmc]

I suggest we model Pull Requests as a CRDT

Each Pull Request should have

• author
• base repo
• base branch
• comparison repo
• comparison branch
• comments
• name
• status open/closed/deleted

Each Comment should have

• author
• text
• created timestamp
• updated timestamp

Access Control

Anyone should be able to open a pull request. The PR author and the repo maintainers should be able to update the PR's status.
Anyone should be able to comment on a pull request and update their own comment. The repo maintainers should be able to delete a comment.

OrbitDB

PRs can be modeled as an OrbitDB Log + Key-Value store (for name & PR status).

Comments can be modeled as an OrbitDB Log, where each element in the list of comments is either

• a new comment:
  author / text / createdAt
• an update to an existing comment with a reference to the comment it updates
  author / text / createdAt / updateRef

Access Control

The OrbitDB maintainers say that it will soon be possible to define a gateway function indicating whether to accept an update to a DB entry, so that we can require that updates have the same author as the referenced PR/comment.

Internals

OrbitDB uses an append-only log called ipfs-log as the persistence layer for an operation-based CRDT. Every entry in the log is saved in IPFS and each points to a hash of previous entry(ies) forming a graph. Logs can be forked and joined back together. The transport layer is pubsub.

Persistence

The maintainer says that "there's a 'pinning' tool coming out soon too, which allows to run a cluster of nodes that can automatically pin the databases, thus making them available when the original poster/user is offline, eg. make sure the content/db is available"

peer-star-app

PRs can be modeled as a Replicable Growable Array + Multi-Value Register (for name & PR status, where repo maintainer's writes > author's writes)
Comments can be modeled as an RGA, in the same fashion as an OrbitDB log (as described above). Each comment / update would be signed with the author's key and any update which does not have the same author as the referenced comment would be discarded

Access Control

The peer-star-app maintainers say that they are currently working on building out the security model, but it should be possible to do the equivalent to what was described above for OrbitDB.

Internals

peer-star-app uses delta CRDTs over a highly scalable ring topology built on floodsub (protocol description). Groups of peers sharing CRDTs are called a Collaboration (analagous to an OrbitDB database)

Persistence

The maintainer say that they are planning to build a service that can be used to persist collaborations

[dirkmc]

Read-only implementation of PR comments using OrbitDB: #47

[magik6k]

On pull request structure - could also have tags field (or tag comment type) for labels/reviewers/assignees/etc (I'm fine with doing that later to keep initial thing simple)