The pivot stopped rendering with:
LinkError: WebAssembly.instantiate(): Import #8 "env" "psp_opfs_load":
function import requires a callable
Nobody changed anything. The 4.x CDN bundle resolves its server WASM with
new URL("../../../server/dist/wasm/perspective-server.wasm", import.meta.url)
which from .../client@4.4.0/dist/cdn/ resolves to
.../npm/@perspective-dev/server/dist/wasm/perspective-server.wasm -- with no
version. jsdelivr serves @latest, so when @perspective-dev/server@5.2.0 was
published on 2026-08-10 every page load began linking a 5.2.0 WASM against a
4.4.0 client. 4.4.1 and 4.5.2 carry the identical unversioned pattern, so no
4.x pin is safe over CDN. Beyond the outage, an unversioned URL means users
execute whatever that package publishes next, unreviewed.
Switch to the /inline entrypoints, which embed the WASM in the Vite build:
no runtime fetch, and the version is fixed by package-lock.json (verified:
zero `new URL(...perspective-server...)` in perspective.inline.js).
- pin client/viewer/viewer-datagrid/server exact at 5.2.0. The explicit
`server` pin matters: client declares it as "" (an empty range), which npm
also resolves to latest -- the same break, at install time instead.
- drop the viewer-d3fc import. pf_app never selects a chart plugin, and d3fc
has no 5.x; loading 4.4.1 against a 5.x viewer only emits
`get_static_config is not a function` per plugin.
- themes move from a CDN <link> to @perspective-dev/viewer/themes.
Verified end-to-end with every non-localhost request aborted: no external
requests are attempted, both custom elements register, the Arrow stream
ingests, and the pivot renders (TOTAL 17,235.97 = -7,573.97 + 30,907.47
- 6,097.53). apache-arrow 21.1.0 ingests cleanly against the 5.2.0 WASM.
Bundle grows 263 KB -> 11.6 MB (5.4 MB gzipped); that is the embedded WASM.
PERSPECTIVE.md also records findings from the same investigation:
- §3a: expression columns are row-level, evaluated before aggregation, so a
ratio like "revenue"/"qty" summed per row is wrong under any pivot (not
just split_by). Fix is a weighted-mean aggregate, whose weight column must
be a NESTED array: ['weighted mean', ['qty']]. Works in 4.4.0 and survives
incremental table.update().
- §2: withdraws the recommendation of the 4.5.1-core + 4.4.1-d3fc pair. It
does not deliver charts, so the trilemma is really a dilemma: inline
bundling XOR charts. dataflow is on that pair and needs the same migration.
- §5: cleanLayout() does not sanitize `aggregates`; guard it before adopting
the weighted-mean pattern or a dropped column aborts the whole restore.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SBt3EtKaP9D2mmWJ6Q4bov
Document the @perspective-dev distribution (not FINOS @finos/perspective):
loader (npm /inline vs CDN), the version trilemma (inline needs 4.5.x,
viewer-d3fc caps at 4.4.1, charts need 4.4.1 — can't have all three),
Arrow vs JSON delivery constraints, deploy pattern, and an upgrade smoke
test. Correct CLAUDE.md's stale perspective.finos.org link to the actual
@perspective-dev repo.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
