Maintaining the Neovim project
==============================

Notes on maintaining the Neovim project.

General guidelines
------------------

* Decide by cost-benefit
* Write down what was decided
* Constraints are good
* Use automation to solve problems
* Never break the API... but sometimes break the UI

Ticket triage
-------------

In practice we haven't found a way to forecast more precisely than "next" and
"after next". So there are usually one or two (at most) planned milestones:

- Next bugfix-release (1.0.x)
- Next feature-release (1.x.0)

The forecasting problem might be solved with an explicit priority system (like
Bram's todo.txt). Meanwhile the Neovim priority system is defined by:

- PRs nearing completion.
- Issue labels. E.g. the `+plan` label increases the ticket's priority merely
  for having a plan written down: it is _closer to completion_ than tickets
  without a plan.
- Comment activity or new information.

Anything that isn't in the next milestone, and doesn't have a finished PR—is
just not something you care very much about, by construction. Post-release you
can review open issues, but chances are your next milestone is already getting
full... :)

Release policy
--------------

Release "often", but not "early".

The (unreleased) `master` branch is the "early" channel; it should not be
released if it's not stable. High-risk changes may be merged to `master` if
the next release is not imminent.

For maintenance releases, create a `release-x.y` branch. If the current release
has a major bug:

1. Fix the bug on `master`.
2. Cherry-pick the fix to `release-x.y`.
3. Cut a release from `release-x.y`.
    - Run `./scripts/release.sh`
    - Update (force-push) the remote `stable` tag.
    - The [nightly job](https://github.com/neovim/bot-ci/blob/master/ci/nightly.sh)
      will update the release assets based on the `stable` tag.

The neovim repository includes a backport [github action](https://github.com/zeebe-io/backport-action).
In order to trigger the action, a PR must be labeled with a label matching the
form `backport release-0.X`. If the label is applied before the PR is merged,
the backport will be filed automatically against the target branch. Otherwise,
comment `\backport` on the merged PR *after* the label has been applied to trigger
a backport. Note, the PR must have a description in the issue body, or the backport
will fail.

Third-party dependencies
--------------

These "bundled" dependencies can be updated by bumping their versions in `third-party/CMakeLists.txt`:
  - [Lua](https://www.lua.org/download.html)
  - [LuaJIT](https://github.com/LuaJIT/LuaJIT)
  - [Luv](https://github.com/luvit/luv)
  - [libtermkey](https://github.com/neovim/libtermkey)
  - [libuv](https://github.com/libuv/libuv)
  - [libvterm](http://www.leonerd.org.uk/code/libvterm/)
  - [lua-compat](https://github.com/keplerproject/lua-compat-5.3)
  - [tree-sitter](https://github.com/tree-sitter/tree-sitter)

`scripts/bump-dep.sh` is a script that can automate this process for `LuaJIT`, `Luv`, `libuv` & `tree-sitter`. See usage guide:
  - Run `./scripts/bump-deps.sh --dep Luv --version 1.43.0-0` to update a dependency.
  See `./scripts/bump-deps.sh -h` for more detailed usage
  - Run `./scripts/bump-deps.sh --pr` to create a pr
  To generate the default PR title and body, the script uses the most recent commit (not in `master`) with prefix `build(deps): `

These dependencies are "vendored" (inlined), we need to update the sources manually:
  - [libmpack](https://github.com/libmpack/libmpack)
  - [xdiff](https://github.com/git/git/tree/master/xdiff)
  - [lua-cjson](https://github.com/openresty/lua-cjson)
  - [Klib](https://github.com/attractivechaos/klib)

We also maintain some forks, particularly for Windows, if we are waiting on upstream changes:
https://github.com/neovim/neovim/wiki/Deps

See also
--------

- https://github.com/neovim/neovim/issues/862
- https://github.com/git/git/blob/master/Documentation/howto/maintain-git.txt