Fabro carried its own Sandbox trait long after every implementation
became a thin layer over the sandbox driver: one production type
implemented it, a delegation macro forwarded it, and each consumer crate
kept hand-written fakes of its thirty methods for tests. The trait
existed to be mocked, and the mocks pinned behavior that no provider
had — canned walk listings that ignored the traversal root, opaque
provider paths, activation failures with no lifecycle behind them.
There is now one sandbox type. RunSandbox keeps fabro's semantics — path
resolution against the run's working directory, the Bash exec policy,
git setup and push, credential refresh — as inherent methods over the
driver's exec, filesystem, search, and git facets, and every consumer
takes Arc<RunSandbox>. The directory, grep, and walk types are the
driver's own, re-exported from fabro-sandbox. The exec policy reports
the provider's measured duration rather than its own clock.
Tests script a sandbox through fabro-sandbox's MockSandbox: a struct of
fields (seeded files, the result every command returns, the platform,
a runtime directory) that hands out a RunSandbox over the driver's
scripted doubles and reads back what the code did — commands, timeouts,
environment, term stops, writes, deletes, existence probes. The
hand-written fakes in fabro-agent, fabro-acp, fabro-hooks,
fabro-workflow, and fabro-server are gone; the one wrapper a git
integration test still needs sits at the driver level, hiding a path
from a real Host sandbox. The refresh-ahead loop takes the refresh as a
closure so its schedule is tested without a sandbox at all.
The driver pin moves to the testing-crate stack head, which gained the
double behavior these ports needed: retention caps on scripted output,
canned walks narrowed to the requested base, upload and download on the
memory filesystem, and recorders for deletes, existence probes, and
term stops. One test that modelled a provider handing back opaque object
paths from a walk is removed: the driver contract has no such thing.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Addresses a Copilot review comment on #653.
The source array is runtime data, usually produced by a model, so its
length is not something a workflow author reviewed. Two changes, so an
over-long array degrades into a clear error rather than memory pressure.
Cap the item count at 1000. Above that the stage fails deterministically
before `parallel.started`, alongside the other for_each contract
violations, and the message says how to reduce the array.
Fork the parent context inside the branch task, after it acquires a
`max_parallel` slot, instead of at dispatch time. Live context copies now
track `max_parallel` rather than item count. Only the branch's own
preamble entry is moved into the task, so the shared stash is not cloned
per branch either.
The reviewer also suggested replacing spawn-all with `max_parallel`
workers pulling from a queue. Not done here: with the fork deferred, a
pending task holds little beyond its item, and reshaping the dispatch
loop would change cancellation and scope-reservation ordering, which
deserves its own review.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
build_branch_plan read the runtime array before run_branches looked at
`simulated`, so every for_each workflow failed under --dry-run with
"for_each source '...' was not found in workflow context". Nothing had
populated the key yet: upstream LLM nodes take Handler::simulate, which
returns no context updates.
A dry run now stands in one placeholder item when the source is absent or
unusable, and simulates the template target once. Graph-shape mistakes
still fail, since catching those is the point of a dry run.
Also from review:
- ITEM_FENCE_PREFIX replaces the bare "untrusted-" literal that
render_item_data and its test each spelled out.
- ItemRecordingHandler no longer guesses an item label by substring
search. Nothing asserted it, and the third item's label "2" matched
stray hex from the random fence tag about two thirds of the time.
- The twin test reads keys::PARALLEL_RESULTS instead of the raw string.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Review follow-ups: the ParallelBranchResult snippet showed status as
String (it is StageOutcome), and the cancellation section implied a
cancelled branch status that the type does not have — cancelled-while-
waiting branches record a failed outcome (reason "branch cancelled")
and the handler returns Error::Cancelled to the run executor.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Cumulative implement + simplify_fable diff recovered from the run's meta
branch (fabro/meta/01KY7YH7RYCJ1BDVTTP96ZA4HV, stage 006 diff.patch).
The run validated this tree clean: cargo nextest (7,007 passed), clippy,
fmt, TS client regen + typecheck, web tests (679 passed), docs check.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
