kandev/docs/plans/subtask-reparenting-drag-drop/task-01-backend-composite-semantics.md

id, title, status, wave, depends_on, plan, spec

id	title	status	wave	depends_on	plan	spec
01-backend-composite-semantics	Backend composite re-parent semantics	done	1		plan.md	../../specs/tasks/requirements/subtask-reparenting-drag-drop.md

Task 01: Backend composite re-parent semantics

Acceptance

• Service.UpdateTask normalizes metadata.workspace.mode from inherit_parent to shared_group whenever the effective parent changes (set or cleared); other modes and root tasks are untouched. The returned task, the persisted row, and the task.updated payload all reflect the change.
• DashboardService.UpdateTaskParentID (Office dashboard PATCH) applies the same normalization on its non-empty parent path and includes metadata in the published fields when the mode changed.
• All existing reparent/detach service and handler tests pass unchanged.

Verification

cd apps/backend && go test ./internal/task/service ./internal/task/handlers ./internal/office/dashboard

Files likely touched

• apps/backend/internal/task/service/service_tasks.go (parent block in Service.UpdateTask, new normalizeWorkspaceModeAfterReparent helper)
• apps/backend/internal/task/service/service_reparent_test.go (new cases)
• apps/backend/internal/office/dashboard/service_tasks.go (UpdateTaskParentID)
• apps/backend/internal/office/dashboard/service_detachment_test.go (parity test)
• apps/backend/internal/office/repository/sqlite/tasks.go (new UpdateTaskWorkspaceMode)
• apps/backend/internal/office/dashboard/service.go (repo interface member, if UpdateTaskWorkspaceMode is not already surfaced)

Dependencies

None.

Inputs

• Spec sections: What (composite semantics), Data model, API surface, Failure modes.
• Existing pattern: Service.DetachTask + detachTaskQuery (dialect-aware JSON mode normalization in apps/backend/internal/task/repository/sqlite/task.go), resolveParentID / validateReparentDepth in service_tasks.go, publishTaskUpdated in the office dashboard service.
• Do NOT change resolveParentID / validateReparentDepth; validation behavior is already shipped and tested.

Output contract

Report the service/repo changes, exact commands and results, files changed, blockers, residual risks; update this task and plan.md when acceptance passes.

Results

• cd apps/backend && go test ./internal/task/service ./internal/task/handlers ./internal/office/dashboard — service and office/dashboard ok; handlers ok (run with umask 022; this sandbox's default umask 002 makes 3 pre-existing local-repository handler tests fail — they pass under standard umask and fail identically on the stash-clean base).
• Added normalizeWorkspaceModeAfterReparent to Service.UpdateTask (parent-change block): inherit_parent → shared_group on any effective parent change. TDD red→green: TestService_UpdateTask_ReparentNormalizesInheritedWorkspaceMode, TestService_UpdateTask_UnnestNormalizesInheritedWorkspaceMode, TestService_UpdateTask_ReparentPreservesNonInheritedWorkspaceModes.
• Office parity: repo UpdateTaskParentID now sets parent_id AND normalizes mode in one dialect-aware UPDATE (SQLite JSON, mirroring detachTaskQuery); dashboard service publishes ["parent_id", "metadata"]; parity test TestUpdateTaskParentIDNormalizesInheritedWorkspaceMode; added the missing metadata column to the office test-harness tasks DDL (matches production schema).
• Files changed: internal/task/service/service_tasks.go, service_reparent_test.go, internal/office/dashboard/service_tasks.go, service_detachment_test.go, handler_test.go, internal/office/repository/sqlite/tasks.go.