The undo substrate. The agent is going to act freely — "empty the garlic bed and
plant cucumbers" runs without a confirmation prompt — and that is only a
defensible default if the result is easy to roll back. So undo lands before the
agent write path, not after it.
The unit of undo is the OPERATION, not the row. A change set groups the
row-level revisions it produced; revert replays their inverses. Emptying a bed
and replanting it touches one object and many plantings, and undoing half of
that is worse than useless.
Two properties shape the rest:
Revert is itself a change set (reverts_id names its target), so history is
append-only and an undo can be undone. git revert, not git reset.
Revert is version-guarded per entity. Every snapshot carries the row's version;
if something edited that row after the change set being reverted, restoring the
old snapshot would silently discard the newer edit, so it is reported as a
conflict and left alone while the rest of the change set still reverts.
The auto-scope is what keeps this invasive but shallow. Service mutations call
record(), which joins the change set on the context if one is open and otherwise
opens a single-op one on the spot. REST handlers needed no edits at all and
every UI mutation lands in history for free; only the agent wraps a whole turn.
Multi-row operations (FillRegion, ClearObject) pass all their changes in one
record call, so a 12-plop fill is one change set with 12 revisions and one undo.
Revisions are buffered and written with their change set in a single
transaction, so an operation that fails partway leaves no half-recorded history.
Recording is best-effort after the fact: the row is already written, so failing
the caller there would report a failure that didn't happen and invite a
duplicate retry. A gap is logged loudly instead.
Two sharp edges handled explicitly rather than by luck:
Deleting an object cascades its plantings away at the FK level, where the
service never sees them. deleteObjectRecording snapshots them first, or the
delete would be listed in history and not actually be undoable.
Restoring deleted rows reuses their ids, and a restored plop needs its object
back first. planRevert runs three explicit passes — restore parents then
children, then updates, then delete created children before their parents —
instead of trusting reverse-seq ordering to happen to be right.
Garden deletion stays out of scope, as designed: the cascade is invisible to the
service and ON DELETE CASCADE would take the history with it. The history UI
will say so rather than pretend otherwise.
Closes#48
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01H3zbym8Doka2d7D48maSgZ
Fixes from the PR #28 adversarial review (considered; not graded).
Correctness / API
- PATCH /objects/:id can now clear nullable color/props back to NULL: the
request takes them as json.RawMessage, and ObjectPatch carries an explicit
Set flag so an explicit `null` (clear) is distinguished from an absent
field (unchanged) — the strongest cross-model finding (6 hits). New test.
Maintainability
- store/plantings.go + plants.go use explicit qualified column lists
(qualifyColumns helper) instead of SELECT *, matching gardens/objects and
surviving a future column add.
- Consolidated objectKinds + plantableByDefault into one kind→traits map.
- objectForRole factors the fetch-then-authorize shared by UpdateObject and
DeleteObject; dropped the redundant kind check in CreateObject
(finalizeObject is the single validation point).
- Request→service mapping via toInput()/toPatch() methods (matches gardens).
- Renamed handler gardenFull → getGardenFull (verbNoun); test helper
decodeGarden → decodeMap; generic bind-error messages.
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01JdQpdYYsTgtkJBxbcpAszi
Garden objects (beds, bags, containers, in-ground, trees, paths,
structures) in one polymorphic table, following the #7 service
conventions.
- store/objects.go: scanObject + Create (RETURNING), Get, ListForGarden
(z_index order), version-guarded Update (RETURNING, returns current row
on conflict), Delete (plantings cascade via FK).
- store/plantings.go + plants.go: the read side /full needs now —
ListActivePlantingsForGarden (removed_at IS NULL) and
ListReferencedPlants (distinct plants used by active plantings). Both
return empty until #14 adds plantings; #12/#14 extend these files.
- service/objects.go: Create/Update(partial patch)/Delete/GardenFull, all
(ctx, actorID, ...) through requireGardenRole(editor for mutations,
viewer for /full). finalizeObject validates kind + shape (rect/circle;
polygon reserved), finite dims in [1cm,100m], NaN/Inf rejection, loose
bbox-overlaps-garden placement (partial overhang OK), hex color, valid
JSON props, name/notes caps; normalizes rotation to [0,360). Plantable
defaults by kind, overridable.
- api/objects.go: POST /gardens/:id/objects, PATCH/DELETE /objects/:id,
GET /gardens/:id/full ({garden,objects,plantings,plants}). props is any
JSON value stored as text; PATCH is partial + required version, 409
returns the current row.
Tests: service (defaults, plantable-by-kind, rotation normalize,
validation rejects incl. off-field/polygon/bad-color/bad-props, partial
patch + version conflict, cross-user ErrNotFound, delete, /full shape) and
api (CRUD + /full, 409 envelope, cross-user 404, polygon/no-kind 400,
props round-trip).
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01JdQpdYYsTgtkJBxbcpAszi
steveandClaude Opus 4.8