For some COBs, parent commits can be specified for actions, for
example, patches will bundle their base and head commits as parents.
When the COB stream performs the revwalk, these commits will be
included, and will not have the manifest file – resulting in an error.
Instead, this error can be matched against, and the commit is skipped
instead. The other errors should still be resurfaced, since a commit
with a manifest should be expected to load the operation correctly,
and the commit should exist in the repository when attempting to load
it.
One might argue that a valid operation with a missing manifest could
occur, but that would mean that `radicle-cob` has performed an invalid
write. This is undetectable by the stream API, and is ambiguous with
the case of non-Op commits.
Make `git2` an *optional* dependency of `radicle-cob`, and refactor
`radicle` to depend on crates that in turn do not depend on `git2`
*non-optionally*
The main offending dependency of `radicle-cob` is `radicle-git-ext`
from the `radicle-git` workspace in repository
(rad:z6cFWeWpnZNHh9rUW8phgA3b5yGt) which *non-optionally* depends on
`git2`.
So, to achieve removal of this dependency:
1. The crate is refactored to depend on the new crates
`radicle-git-ref-format` `radicle-git-metadata`, and
`radicle-oid` introduced in the previous commits, instead of
`radicle-git-ext`.
2. Some code from the `radicle-git-ext` crate in the `radicle-git`
workspace in repository (rad:z6cFWeWpnZNHh9rUW8phgA3b5yGt) is
copied. See `crates/radicle-cob/src/backend/git/commit.rs`.
This cascades to `radicle` and its dependents.
Firstly, the there is an
`impl Deref<Target=git2::Oid> for radicle_git_ext::Oid`. This made
it very convenient to just deref to obtain the wrapped `git2::Oid`,
so there are many expressions of the shape `*oid` in `radicle` and
its dependents. However `radicle-oid` does not provide
`impl Deref<Target=git2::Oid> for radicle_oid::Oid`, as notably,
`Target` is an associated type, and not a type parameter, so an
implementation of `Deref` would tie the new `Oid` too tightly to a
particular implementation.
Instead, work with `impl From<radicle_oid::Oid> for git2::Oid`
(which can be enabled using the feature flag `radicle-oid/git2`).
This explains the changes from `*oid` to `oid.into()` at every
transition to "`git2` land".
Secondly, `radicle` and its dependents are refactored to also depend
on `radicle-git-ref-format` and (much less prominently)
`radicle-git-metadata` instead of `radicle-git-ext`
This is to avoid pulling in `git2` via these dependencies.
Thirdly, as the re-exports in `crates/radicle/src/git.rs` change,
they are at the same time also cleaned up. Notably, the types from
`radicle-git-ref-format` are re-exported under `fmt` only, not "twice".
While overall this obviously is very much a breaking change, these
changes should mostly amount to changing from `Deref` to `Into`, i.e.,
`*oid` → `oid.into()` and rewriting imports for `radicle::fmt`.
This is indicated by the mostly mechanical nature of the changes to
`crates/radicle-{cli,node,remote-helper}`.
A refactoring internal to the `radicle` crate, with the goal of
making dependency on `git2` clearer and more controlled.
`radicle::raw` is changed from a complete re-export of `git2`
to a module that selectively re-exports (many) members of `git2`.
required to build the workspace (potentially breaking dependents
outside the workspace, but given just how many types are
re-exported, this seems unlikely).
In the future, no more `use git2::…` statements should be added
outside of `crates/radicle/src/git/raw.rs`. This is in an effort to
decrease dependence on `git2` in the future.
Introduce a new `stream` module to `radicle::cob`. The purpose of this module is
to provide an API for iterating over a COB's operations, given a range of
commits.
The `CobStream` trait provides the generic API for implementing and using, while
`Stream` provides a concrete implementation using the `git2` crate.
The approach is to use a `git2::Revwalk` for walking over each commit in the
range, then loading the `Op` for that commit – skipping any commits that are
unrelated to that COB type, in the case of associated COBs.
The `Stream` is tested using some properties of the API.
The next steps are to introduce specialised types for `Patch` and `Issue` to
ensure that it works for those.
Fintan Halpenny
Lorenz Leutgeb
