Chris Tate
42954a3266
node:test's mock.fn(original[, implementation]) and t.mock.fn compile.
A Mock<F> is the function-with-properties record { %call, mock }: the
callable is a wrapper closure that shares the mock context with the mock
field. The context records each call's arguments, result, error and this,
and keeps the current implementation, the original and the one-time
implementations by call index. fn.mock supports, as in Node 24.22:
- calls, read as a copy of the log;
- callCount();
- mockImplementation(fn);
- mockImplementationOnce(fn[, onCall]), for the next call by default, a
later registration for the same index replacing the earlier one;
- resetCalls();
- restore(), which brings back the original.
A throwing implementation records the error and rethrows it. Functions
with fixed parameters or a single rest array parameter are supported; a
union return type needs an undefined arm. mock.fn() without an original,
mock.method, the tracker's reset and restoreAll, and t.mock.method are
refused with SC2020.
The node:test fixture mock-fn compares the behavior with Node, and
tests/diagnostics/mock-fences.ts covers the refusals.
Node compatibility ledger
This workspace package owns scriptc's Node.js parity system.
node-v24.jsonpins the Node release tag, commit, and canonical docs/source inputs.static-support.jsonoverlays dedicated compiler paths and their internal test evidence on the compiler's generated surface manifest.generated/node-v24-internal.jsonis the engineering ledger, including implementation evidence and repository test paths.generated/node-v24-backlog.jsonis the internal tier-specific work queue. It separates verification, implementation, explicit-refusal replacement, and partial-surface audit work, and prioritizes stable Node APIs above experimental, deprecated, and legacy APIs.docs/src/generated/node-v24-compatibility.jsonis the stripped public artifact consumed by the docs website. It contains compiler-relevant runtime APIs, statuses, verification bases, and user-facing details; documentation, metadata, command-line/configuration entries, and rows that are N/A for native execution remain internal.
Statuses are evidence-aware: supported and partial require test evidence; refused requires an explicit compiler diagnostic or native throwing stub; not-implemented is the actionable backlog for an owned API family with no implementation match; by-design records an architectural exclusion; unreviewed still needs classification; and not-applicable is not a runtime API for that execution tier.
Run pnpm node-compat:backlog from the repository root for a summary. The filters --tier, --action, --priority, --chapter, and --status compose; use --format=json or --format=tsv for tooling.
Run pnpm node-compat from the repository root after changing the Node pin or the support manifest. pnpm node-compat:check is the offline drift/evidence gate; pnpm --filter @internal/compatibility check:upstream additionally verifies the pinned upstream inputs over the network.