* fix(#1572): preserve must_haves object-lists across frontmatter set/merge spliceFrontmatter round-tripped the WHOLE frontmatter through extractFrontmatter (a scalar-only parser) then reconstructFrontmatter (a lossy serializer), so any must_haves object-list — artifacts {path, provides}, prohibitions {statement, status} — was flattened to scalar strings and re-emitted as a malformed inline array whenever an UNRELATED field changed, silently dropping every provides:/ status: value. The write now preserves the original raw text for any top-level key whose value is structurally unchanged between the original parse and the new object (generalizing the existing whole-document no-op guard to per-key fidelity), and regenerates only the key that actually changed. The key set is still defined by newObj (the cmdSet/cmdMerge flow always passes the full merged object). spliceFrontmatter's only callers are cmdFrontmatterSet/Merge — the STATE.md read-modify-write family calls reconstructFrontmatter directly and is unaffected. Regression cases folded into tests/frontmatter-cli.test.cjs: artifacts/prohibitions object-lists survive set and merge; idempotent on repeat sets. Asserted via parseMustHavesBlock (the structure-preserving parser). * chore(#1572): backfill changeset pr ref to 1656 * fix(#1572): fail-closed when set/merge would emit [object Object] (codex review) Adversarial review (codex, gpt-5.5/high) flagged that directly setting a must_haves object-list (a CHANGED key) still routed through the lossy reconstructFrontmatter, emitting literal "[object Object]" and destroying the data. The reported case (mutating an UNRELATED field) was already fixed by per-key raw-text preservation, but the changed-object-list path was still silently lossy. Add fail-closed: when a regenerated key's text contains the "[object Object]" sentinel, spliceFrontmatter throws — cmdFrontmatterSet/Merge error out WITHOUT writing, directing the user to edit the file directly. The no-frontmatter (generate-from-scratch) path is guarded the same way. Adds a test that a refused set leaves the file unchanged and the original object-list intact. Codex finding #2 (a contrived flattened-projection no-op) is a deeper limitation noted in the PR — non-destructive, and the fail-closed message already directs users to edit object-list blocks directly. * test(#1572): add spliceFrontmatter per-key preservation + fail-closed unit coverage Stryker mutates gsd-core/bin/lib/frontmatter.cjs against tests/frontmatter.{property,unit}.test.cjs (MinScore 62). The #1572 regression cases live in frontmatter-cli.test.cjs, which is NOT in Stryker's test set, so the new functions (sliceTopLevelFrontmatterSegments, the per-key preserve/regenerate/drop/append loop, regenerateFrontmatterKey's [object Object] fail-closed) had surviving mutants that dropped the module below threshold. Add unit-level coverage in frontmatter.unit.test.cjs exercising every new branch directly via spliceFrontmatter: unchanged object-list preserved (provides survives) when a scalar sibling changes; changed scalar regenerates only that key; orphan keys dropped; new keys appended; indented nested block stays attached to its parent key; whole-document no-op returns input verbatim; both fail-closed paths (changed object-list + no-frontmatter) throw.
Changeset Fragments
This directory holds per-PR CHANGELOG fragments. Every PR with user-facing changes drops one (or more) <random-name>.md files here describing its CHANGELOG entry. Fragments are consolidated into the top-level CHANGELOG.md at release time.
Why
Two PRs that both edit the ### Fixed block of CHANGELOG.md always conflict on merge — git can't pick a serialization order without human input. Two PRs that each add a fresh .changeset/<unique-name>.md never conflict because they don't share lines.
See #2975 for the full rationale.
Adding a fragment
node scripts/changeset/new.cjs \
--type Fixed \
--pr 1234 \
--body "fix the thing — explain the user-visible change in one sentence"
This writes .changeset/<adjective>-<noun>-<noun>.md with frontmatter and a body. Three random words → concurrent PRs don't collide.
Format
---
type: Fixed
pr: 1234
---
**`/gsd-foo` no longer drops trailing slashes** — explain the user-visible change.
Allowed type: values follow Keep a Changelog: Added, Changed, Deprecated, Removed, Fixed, Security.
Opting out
PRs that legitimately have no user-facing impact can add the no-changelog label. CI honors it. When unsure, add the fragment.
At release time
Promotion is automatic. The release workflow's finalize job runs:
node scripts/changeset/cli.cjs render --version vX.Y.Z --date YYYY-MM-DD --allow-empty
This reads every fragment, groups bullets by type:, replaces ## [Unreleased] with a new ## [vX.Y.Z] - YYYY-MM-DD block, opens a fresh ## [Unreleased] above, and deletes consumed fragments. The --allow-empty flag ensures a no-change release still gets a dated heading (with a _No notable changes._ placeholder). A subsequent verify step confirms the promotion landed correctly. Maintainers do not run this by hand.
Archived fragments
.changeset/archived/ holds fragments for already-shipped releases (≤ 1.3.1), retained for provenance. Their content was hand-curated into the dated ## [1.x.y] sections of CHANGELOG.md during the #690 backfill — they were never consumed by render. All changeset tooling enumerates .changeset/ non-recursively, so archived fragments are never picked up or rendered. Do not move them back to the top level.