feat(auto-pull): opt-in background fast-forward for registered repos

Add a C2-guarded PWD handler that background fast-forwards the fish-config
repo (baseline) plus any repos in a machine-local registry. Safety is
guaranteed by _auto_pull_sync: clean tree + has-upstream + --ff-only, else
no-op. Never rebases, merges, or overwrites work.

- conf.d/auto-pull.fish: --on-variable PWD handler, throttled to fire once
  per repo entry; spawns a --no-config child to run the worker
- functions/_auto_pull_sync.fish: the ff-only worker (safe on any branch)
- functions/auto-pull.fish: add/remove/list/status registry management,
  usable even when C2 is disabled
- completions/auto-pull.fish: subcommand + registered-repo completions

Registry lives at ~/.config/.user-dots/fish/auto-pull.list (machine-local,
never committed).
This commit is contained in:
2026-06-19 02:21:21 -04:00
parent 1433844c2b
commit 261e663e97
4 changed files with 292 additions and 0 deletions
+33
View File
@@ -0,0 +1,33 @@
# Copyright (C) 2026 Rootiest
# SPDX-License-Identifier: AGPL-3.0-or-later
# Completions for the `auto-pull` registry command.
function __auto_pull_registered
set -l list "$XDG_CONFIG_HOME/.user-dots/fish/auto-pull.list"
test -r "$list"; or return
for l in (command cat "$list" 2>/dev/null)
test -n "$l"; or continue
printf '%s\t%s\n' (path basename "$l") "$l"
end
end
set -l subcmds list add remove status
# Subcommands (only as the first argument).
complete -c auto-pull -f -n "not __fish_seen_subcommand_from $subcmds" \
-a list -d 'Show registered repos'
complete -c auto-pull -f -n "not __fish_seen_subcommand_from $subcmds" \
-a add -d "Register a repo (default: current)"
complete -c auto-pull -f -n "not __fish_seen_subcommand_from $subcmds" \
-a remove -d 'Unregister a repo'
complete -c auto-pull -f -n "not __fish_seen_subcommand_from $subcmds" \
-a status -d 'Show enabled state and registry path'
complete -c auto-pull -f -n "not __fish_seen_subcommand_from $subcmds" \
-s h -l help -d 'Show help'
# `add` takes a directory path.
complete -c auto-pull -n "__fish_seen_subcommand_from add" -a '(__fish_complete_directories)'
# `remove` completes registered repo basenames.
complete -c auto-pull -f -n "__fish_seen_subcommand_from remove" -a '(__auto_pull_registered)'
+62
View File
@@ -0,0 +1,62 @@
# Copyright (C) 2026 Rootiest
# SPDX-License-Identifier: AGPL-3.0-or-later
# ╭──────────────────────────────────────────────────────────╮
# │ Auto-Pull (C2 — Autoexec) │
# ╰──────────────────────────────────────────────────────────╯
#
# Background, fast-forward-only `git pull` for opted-in repositories. Fires
# when the working directory enters the fish-config repo (always covered as a
# baseline) or any repository registered via the `auto-pull` command. The
# actual sync is delegated to `_auto_pull_sync`, which only ever fast-forwards
# a clean repo — see that function for the full safety contract.
#
# Manage the registry with: auto-pull add / remove / list / status
# C2 guard: when auto-execution is disabled, do not register the handler.
__fish_config_op_enabled __fish_config_op_autoexec; or exit
# SYNOPSIS
# __auto_pull_on_pwd (event handler, --on-variable PWD)
#
# DESCRIPTION
# On every directory change, checks whether the new $PWD is inside a
# registered repository (or the fish-config baseline) and, if so, kicks a
# background fast-forward. A throttle global ensures it fires once per
# repository entry rather than on every sub-directory change.
function __auto_pull_on_pwd --on-variable PWD
set -q __fish_config_dir; or set -g __fish_config_dir $XDG_CONFIG_HOME/fish
set -l list "$XDG_CONFIG_HOME/.user-dots/fish/auto-pull.list"
# Candidate roots: the fish-config repo plus the user's registry.
set -l roots $__fish_config_dir
test -r "$list"; and set -a roots (command cat "$list" 2>/dev/null)
# Find the registered root containing $PWD (exact match or a sub-directory).
set -l hit
for r in $roots
test -n "$r"; or continue
if test "$PWD" = "$r"; or string match -q -- "$r/*" "$PWD"
set hit "$r"
break
end
end
# Outside every registered repo: clear the throttle so re-entry re-syncs.
if test -z "$hit"
set -e __auto_pull_last
return
end
# Already synced for this repo entry — skip until we leave and return.
test "$hit" = "$__auto_pull_last"; and return
set -g __auto_pull_last "$hit"
# Background fast-forward. A --no-config child sources just the worker so
# it stays fast and free of shell side-effects; real `git`, no shadows.
set -l worker "$__fish_config_dir/functions/_auto_pull_sync.fish"
test -r "$worker"; or return
fish --no-config -c 'source $argv[1]; _auto_pull_sync $argv[2]' -- "$worker" "$hit" &
disown 2>/dev/null
end
+47
View File
@@ -0,0 +1,47 @@
# Copyright (C) 2026 Rootiest
# SPDX-License-Identifier: AGPL-3.0-or-later
# SYNOPSIS
# _auto_pull_sync <dir>
#
# DESCRIPTION
# Best-effort, side-effect-safe fast-forward of a single git repository.
# Performs a fetch and a fast-forward-only merge of the current branch's
# upstream, but only when it is completely safe to do so: the work tree
# must be clean, the branch must have an upstream, and the merge must be a
# true fast-forward. Any failed precondition makes the function a no-op.
# It never rebases, never creates a merge commit, and never overwrites
# committed or uncommitted work — worst case it does nothing.
#
# Intended to be invoked in the background by the auto-pull PWD handler
# (conf.d/auto-pull.fish), but safe to call directly.
#
# ARGUMENTS
# dir Absolute path to the git repository to fast-forward
#
# RETURNS
# 0 Fast-forward applied (or already up to date)
# 1 A precondition failed; nothing was changed
#
# EXAMPLE
# _auto_pull_sync ~/.config/fish
function _auto_pull_sync --description 'Fast-forward a repo when clean and a ff is possible'
set -l d $argv[1]
test -n "$d"; or return 1
# Must be a git work tree.
command git -C "$d" rev-parse --is-inside-work-tree >/dev/null 2>&1; or return 1
# Work tree must be clean (no staged or unstaged changes).
command git -C "$d" diff --quiet 2>/dev/null
and command git -C "$d" diff --cached --quiet 2>/dev/null
or return 1
# Current branch must have an upstream to fast-forward against.
command git -C "$d" rev-parse --abbrev-ref --symbolic-full-name '@{u}' >/dev/null 2>&1
or return 1
# Fetch, then fast-forward only. --ff-only aborts (no-op) on any divergence.
command git -C "$d" fetch -q 2>/dev/null; or return 1
command git -C "$d" merge -q --ff-only '@{u}' >/dev/null 2>&1
end
+150
View File
@@ -0,0 +1,150 @@
# Copyright (C) 2026 Rootiest
# SPDX-License-Identifier: AGPL-3.0-or-later
# SYNOPSIS
# auto-pull [list]
# auto-pull add [PATH]
# auto-pull remove <NAME|PATH>
# auto-pull status
#
# DESCRIPTION
# Manages the auto-pull registry: the list of repositories that are
# background fast-forwarded when you enter them (see conf.d/auto-pull.fish
# and _auto_pull_sync). The fish-config repo is always covered as a baseline
# and does not need to be added. The registry is a plain text file, one
# absolute git-toplevel path per line, stored machine-locally in
# ~/.config/.user-dots/fish/auto-pull.list (never committed to the config).
#
# Registry management works regardless of the C2 auto-execution guard; only
# the background sync itself is gated by __fish_config_op_autoexec.
#
# ARGUMENTS
# list Show registered repos (default when no subcommand given)
# add [PATH] Register PATH's git root; defaults to the current repo
# remove <NAME|PATH> Unregister by basename or exact path
# status Show whether auto-pull is enabled and the registry path
# -h, --help Show this help message
#
# RETURNS
# 0 Subcommand succeeded
# 1 Bad usage, target is not a git repo, or target not registered
#
# EXAMPLE
# cd ~/src/qmk_firmware; and auto-pull add
# auto-pull add ~/work/api
# auto-pull list
# auto-pull remove qmk_firmware
function auto-pull --description 'Manage the auto-pull repository registry'
set -l c_head (set_color --bold cyan)
set -l c_cmd (set_color --bold white)
set -l c_flag (set_color yellow)
set -l c_ok (set_color green)
set -l c_warn (set_color yellow)
set -l c_err (set_color red)
set -l c_dim (set_color brblack)
set -l c_reset (set_color normal)
set -q __fish_config_dir; or set -l __fish_config_dir $XDG_CONFIG_HOME/fish
set -l list "$XDG_CONFIG_HOME/.user-dots/fish/auto-pull.list"
set -l cmd $argv[1]
set -e argv[1]
if test "$cmd" = -h; or test "$cmd" = --help; or contains -- -h $argv; or contains -- --help $argv
echo "$c_head""Usage:$c_reset $c_cmd""auto-pull$c_reset $c_flag""[list | add | remove | status]$c_reset $c_dim""[PATH|NAME]$c_reset"
echo
echo " Manage the registry of repos that are background fast-forwarded on entry."
echo
echo "$c_head""Subcommands:$c_reset"
echo " $c_flag""list$c_reset Show registered repos (default)"
echo " $c_flag""add$c_reset $c_dim""[PATH]$c_reset Register PATH's git root (default: current repo)"
echo " $c_flag""remove$c_reset $c_dim""<NAME|PATH>$c_reset Unregister by basename or exact path"
echo " $c_flag""status$c_reset Show enabled/disabled state and registry path"
echo " $c_flag-h$c_reset, $c_flag--help$c_reset Show this help message"
return 0
end
switch "$cmd"
case '' list
echo "$c_head""Auto-pull registry:$c_reset"
echo " $c_dim$__fish_config_dir$c_reset $c_dim(fish-config, baseline)$c_reset"
if test -r "$list"
for l in (command cat "$list" 2>/dev/null)
test -n "$l"; or continue
echo " $l $c_dim("(path basename "$l")")$c_reset"
end
end
return 0
case add
set -l target $argv[1]
test -n "$target"; or set target $PWD
set -l root (command git -C "$target" rev-parse --show-toplevel 2>/dev/null)
if test -z "$root"
echo "$c_err""auto-pull: not a git repository: $target$c_reset" >&2
return 1
end
if test "$root" = "$__fish_config_dir"
echo "$c_warn""auto-pull: fish-config is always covered (baseline); nothing to add$c_reset"
return 0
end
command mkdir -p (path dirname "$list")
test -f "$list"; or command touch "$list"
if contains -- "$root" (command cat "$list" 2>/dev/null)
echo "$c_dim""auto-pull: already registered: $root$c_reset"
return 0
end
echo "$root" >>"$list"
echo "$c_ok""→ auto-pull added: $root$c_reset"
return 0
case remove rm
set -l target $argv[1]
if test -z "$target"
echo "$c_err""auto-pull: usage: auto-pull remove <NAME|PATH>$c_reset" >&2
return 1
end
if not test -r "$list"
echo "$c_dim""auto-pull: registry is empty$c_reset"
return 1
end
set -l kept
set -l removed
for l in (command cat "$list" 2>/dev/null)
test -n "$l"; or continue
if test "$l" = "$target"; or test (path basename "$l") = "$target"
set -a removed "$l"
else
set -a kept "$l"
end
end
if test -z "$removed"
echo "$c_err""auto-pull: not registered: $target$c_reset" >&2
return 1
end
if test -n "$kept"
printf '%s\n' $kept >"$list"
else
printf '' >"$list"
end
echo "$c_warn""→ auto-pull removed: $removed$c_reset"
return 0
case status
if __fish_config_op_enabled __fish_config_op_autoexec
echo "$c_ok""auto-pull: ENABLED$c_reset $c_dim(C2 auto-execution on)$c_reset"
else
echo "$c_warn""auto-pull: DISABLED$c_reset $c_dim(via __fish_config_op_autoexec)$c_reset"
end
set -l repos
test -r "$list"; and set repos (command cat "$list" 2>/dev/null | string match -rv '^\s*$')
echo " registered repos: "(count $repos)" $c_dim(+ fish-config baseline)$c_reset"
echo " list file: $c_dim$list$c_reset"
return 0
case '*'
echo "$c_err""auto-pull: unknown subcommand: $cmd$c_reset" >&2
echo "$c_dim""try: auto-pull --help$c_reset" >&2
return 1
end
end