submarine/docs/actions.md

Actions (draft)

Status: Restore is implemented (key x, decisions in D23). Stage pin is still a draft; its open questions are at the end.

Principle

Offer as few actions as possible, but enough to work with submodules. submarine shows what differs from what git records. The actions resolve such a difference in one of two directions:

Action	Direction	Key
Restore	The worktree follows the recorded state	x
Stage pin	The recorded state follows the worktree	s

There is nothing else for now. Committing, pushing, switching branches and bumping a pin to the tip are done outside submarine. A bump is "check out the tip in the submodule, then s".

Restore

Makes the selected repository, and everything below it, exactly what git records. It works on any submodule and on the superproject (header selected). Restoring the superproject gives the exact project that the current root commit specifies, with the pins you have staged.

Target

Selected	Target commit	Branch
Superproject	HEAD	stays on the current branch
Submodule	The pin in the parent's index (what the UI shows as Pinned); with a staged pin you choose, see below	see Branches
Nested submodule, during the recursion	The gitlink in the restored parent's index	as for a submodule

Staged pins are kept, at every depth. A staged pin is a decision, not drift. Each repository's files are reset to its HEAD, but its staged pins stay in its index, and the submodules below are restored to them. So a nested submodule with a staged pin and uncommitted changes keeps the pin and is reset to it; its changes are discarded (and listed in the question).

Choosing the pin. If the selected submodule has a staged pin itself, x first asks which pin to restore to:

Restore libs/staged to  s staged pin · c committed pin (unstages it)     any other key cancels

• s: the staged pin, which stays staged.
• c: the committed pin (the gitlink in the parent's HEAD). The parent's index is set back to it, which is how a pin is unstaged in submarine.

The loss check then runs for the chosen pin (the two can differ: a staged commit that exists only locally is lost by c, not by s).

Two exceptions, where a staged pin is not kept:

• The repository moves. If a repository is off its pin, restore checks out another commit; staged pins in its own index belonged to the old one. They are counted as a loss (2 staged pins), so the question appears. Its submodules follow the target commit's tree.
• An added, not yet committed submodule is no staged pin: its .gitmodules entry is reset with the other files. Its directory then counts as an untracked file.

Postconditions

After a successful restore of repository R with target T:

1. R's HEAD is T. The index and the worktree equal T's tree, except for the staged pins that were kept. No modified, added, removed or conflicted files remain.
2. No in-progress operation remains in R: merge, rebase, cherry-pick, revert.
3. No untracked files or directories remain in R. This includes leftover directories of submodules that T no longer has (untracked repository). Ignored files are kept.
4. Every submodule that R's index records is present and initialized, even if it was never initialized, is inactive (submodule.<name>.active) or has update = none / merge / rebase configured. Its URL comes from T's .gitmodules (synced into the config).
5. Each of those submodules is restored the same way, with its gitlink in R's index (T's, or a kept staged pin) as its target, recursively at any depth.

So the subtree shows in sync everywhere, except for states restore does not change: unpushed, behind/ahead of the ref, and detached HEAD on pin.

The recursion follows T, not the tree loaded in the UI. A submodule that is only in T (for example, after switching branches) is initialized. A submodule that is only on disk is deleted as an untracked directory.

Branches

• Superproject: stays on its branch. The branch is not moved, since the target is its own HEAD.
• Submodule on the pin: if HEAD is a branch that points at the target, the branch stays checked out.
• Submodule off the pin: HEAD is detached at the target. The branch that was checked out is not moved, so its commits stay on it.

Restore never moves, creates or deletes a branch.

What can be lost

Restore discards work. The things it can lose:

Lost	Where it comes from
Changed files	modified, added, removed, renamed files (changed)
Untracked files	changed (untracked)
Conflicts and in-progress operations	conflict; merge, rebase, cherry-pick, revert state
Commits	A detached HEAD off the pin whose commits are on no branch, tag or remote ref (only the reflog still has them)
Staged pins	Staged pins in a repository that restore moves to another commit (see Target)
Repositories	An untracked directory that is a repository with its own .git directory (a clone that was never added as a submodule). Its commits may exist nowhere else. A removed submodule whose git directory is absorbed into .git/modules loses only its worktree. Its objects stay

Nothing else is lost. Branches, stashes, remote refs, ignored files and absorbed submodule git directories stay.

Confirmation

Restore asks only if something would be lost. Never asking is unsafe (git clean -ff deletes repositories that exist nowhere else, and nothing undoes a restore); always asking puts a question on the harmless, common cases (off pin, missing, a staged pin) and teaches a reflexive y.

• Nothing would be lost: restore runs at once.

• Something would be lost: a line above the footer says what is discarded, summed over the whole subtree on disk:

  Restore src/app? Discards 7 changed files in 3 repositories, 2 commits on no branch, 1 untracked repository.   y restore · n cancel
  

  y runs it, any other key cancels.

• The state can't be read for a repository: it is counted as n repositories of unknown state and needs the same y.

The check reads the disk at the moment of the keypress (RestoreLoss), not the loaded statuses, so loading or stale statuses don't matter. Nothing is lost that is not in the table above; ignored files are never touched.

Network

A restore may need objects that are not on disk: a submodule that was never cloned (no git directory in .git/modules), or a target commit that was never fetched. Restore may clone and fetch, but only what is missing, non-interactively (GIT_TERMINAL_PROMPT=0, ssh BatchMode) and with a timeout. If the commit is on no remote, restore fails with commit … is not available on any remote. This is the one place besides f that uses the network (decision D23).

Running, progress and errors

• A line above the footer shows checking … and then restoring … with a spinner. Only one restore runs at a time; pressing x meanwhile flashes wait for the restore of src/app to finish. Everything else keeps working.
• A running fetch does not block a restore.
• Done: flash restored src/app; the app reloads the tree and all statuses, because the structure can have changed.
• Failure: the restore stops with git's message, shown in red above the footer (restore of src/app failed: …) until the next key. Restore is idempotent, so it can be run again after fixing the cause. Repositories that were restored before the failure stay restored.

Implementation note

git.Provider.Restore (internal/submodule/git/restore.go) walks the repositories itself, top-down; the children of a repository run concurrently, bounded by the provider's semaphore. For each repository (T = target) it runs, with -c submodule.recurse=false:

cat-file / fetch --all            # only if T is missing locally
rebase|cherry-pick|revert --quit  # whichever is in progress; --quit, not --abort: no ref moves
checkout --force --detach T       # only if HEAD is not T, so a branch is never moved
reset --hard                      # also ends a merge
update-index --cacheinfo …        # put the staged pins back (only if HEAD did not move)
clean -ffd                        # -ff: untracked repositories too; ignored files stay
submodule sync
submodule update --init --checkout --force -- <not yet initialized children>
# then every gitlink of the index (ls-files -s) is restored the same way

--checkout overrides submodule.<name>.update, and the explicit paths override submodule.<name>.active, so no child module is skipped.

With c the parent's index gets the committed pin first (update-index --cacheinfo in the parent).

RestoreLoss (lossOf) follows the repositories on disk: per repository status (without submodules), the in-progress state files, and rev-list --count HEAD --not --branches --tags --remotes if HEAD is not the target. A directory in the untracked list is searched for .git directories (a standalone repository); an absorbed submodule leaves only a .git file and loses just its worktree.

Stage pin

Records the commit checked out in a submodule as its new pin in the parent's index. It is the same as git add <path> in the parent, but only when it is safe.

Available when

All of:

• the selected node is a submodule, not the superproject;
• it is off pin (Checkout == CheckoutDiffers): HEAD differs from the pin in the parent's index;
• its worktree is clean (Worktree == WorktreeClean). Uncommitted changes, untracked files and conflicts count as dirty, the same rule as the changed issue. A moved nested pin counts as a change too, so nested submodules are staged bottom-up: first inside the submodule, then the submodule itself (after a commit in it, outside submarine).

Changes inside nested submodules don't count. Like the changed issue, staging only looks at the submodule's own worktree.

Effect

• The parent's index records the submodule's HEAD as the gitlink of its path. Nothing else changes: no worktree, no other index entry, no commit.
• The submodule then shows staged (or ● next to an issue), and the off pin issue is gone.
• If the checkout equals the pin in the parent's HEAD, staging removes the staged pin instead (the index equals HEAD again).
• If the checked-out commit is not pushed, it is staged anyway. The row then shows unpushed (Danger), which is the warning.
• There is no confirmation: nothing is lost.
• Undo: restore the submodule and choose c (committed pin), see Target.

Implementation note

# in the submodule
git rev-parse HEAD                  # must still be the SHA shown in the UI, else abort
# in the parent
git update-index --cacheinfo 160000,<sha>,<path>

update-index stages exactly the SHA that was checked, independent of the worktree. Flash: staged pin of src/app on success; git's message on failure.

Keys and palette

Both are submodule keys (keyMap.Submodule), shown in the detail pane's palette, or in the footer when the pane can't show it. Restore is always offered: it is idempotent, and the palette is static.

Key	Action	Pressed when not possible (flash)
x restore	Restore the selection	this data source can't restore (mock); wait for the restore of … to finish
s stage pin	Stage pin, not implemented	src/app is on its pin / src/app has uncommitted changes; commit or restore them first / the superproject has no pin

R would sit next to r (reload), a dangerous mix-up for a destructive action, hence x.

Testing

• Provider (restore_test.go), on fixtures from scripts/make-fixture.sh: a restored superproject is exact (every repository clean, submodule status --recursive without prefixes, libs/missing initialized), branches are not moved, ignored files survive, a merge and a rebase in progress end, a standalone clone and a removed submodule's directory are deleted, a missing submodule is cloned again, update = none and inactive submodules are restored, an unavailable commit is reported. The loss is empty for off pin, missing and unpushed submodules, counts files, nested changes, merges, detached commits (not those on a branch) and standalone repositories.
• UI (internal/tui/restore_test.go): restores at once without a loss, asks with one (y restores, anything else cancels), the mock can't restore.
• By hand in tmux on a fixture, see architecture.md.

Open questions

Decided for restore: ignored files are kept (clean without -x); a submodule is restored to the index gitlink, so a staged pin is its target and survives; restore may clone and fetch what is missing; the key is x; it asks only if something would be lost.

Open (stage pin):

1. Key. s?
2. Palette. Show it always (like restore), or only while it applies?