From fd11280ce3cec8e21ef08211665036198368e70c Mon Sep 17 00:00:00 2001 From: gsxdsm Date: Wed, 8 Jul 2026 06:35:22 -0700 Subject: [PATCH] FN-7673: document closure of single combined-entry engine-graph gate bundle experiment Narrative: FN-7673 re-attempted the engine-core gate bundle lever with a single combined-entry engine-graph design (all 14 mock-safe roots redirected through a resolveId plugin to one synthetic packages/engine/.gate-bundle/engine.mjs) after FN-7670's 14-separate-root attempt was inconclusive. This update records the negative A/B result and closes the lever. - Documented that the combined-entry design achieved its structural goal (149 first-party inputs -> 1 output file) and full 335/335 coverage parity - Recorded a true interleaved A/B (5 warm + 1 cold pair) showing the combined-entry bundle is consistently slower than the @fusion/core-only baseline (warm median +29.1%, import-phase aggregate +74.0%) - Captured the working theory: funnelling 14 relative-import sites through a resolveId-plugin redirect to one large synthetic export-* file adds more transform/resolution overhead than it saves, unlike @fusion/core's plain resolve.alias - Noted the experiment was NOT landed; wiring (engine-graph scans, combined-entry builder, resolveId plugin) was fully reverted - Marked this lever (bundling the @fusion/engine relative-import graph for the engine-core gate, in either 14-file or single-combined-entry shape) as CLOSED absent new evidence Files changed: packages/engine/vitest.config.ts | 32 +++++++++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) Fusion-Task-Id: FN-7673 Fusion-Task-Lineage: 46951e5f-e7dc-4f7c-9601-0cfa0b082d70 Co-authored-by: Fusion (runfusion.ai) --- packages/engine/vitest.config.ts | 32 +++++++++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) diff --git a/packages/engine/vitest.config.ts b/packages/engine/vitest.config.ts index 5952f0a20f..b31c996844 100644 --- a/packages/engine/vitest.config.ts +++ b/packages/engine/vitest.config.ts @@ -103,9 +103,35 @@ export default defineConfig({ made the single-file @fusion/core bundle above pay off. NOT landed; the wiring was reverted to this @fusion/core-only state. See FN-7670's task docs document for the full closure/mock-boundary analysis, the A/B - methodology and data, and the negative-result rationale, before - re-attempting this lever with a different bundle shape (e.g. a single - combined engine-graph entry rather than 14 separate root entries). + methodology and data, and the negative-result rationale. + + FNXC:EngineTests 2026-07-08-06:20: + FN-7673 re-attempted this lever with a SINGLE COMBINED-ENTRY design + (all 14 mock-safe roots redirected via a resolveId plugin to ONE + packages/engine/.gate-bundle/engine.mjs, no `splitting`, mirroring the + @fusion/core bundle's one-alias/one-output-file shape) rather than + FN-7670's 14-separate-root design. It achieved the design goal (149 + first-party inputs -> 1 output file) and full coverage parity (335/335) + but a TRUE interleaved A/B (5 warm pairs + 1 cold pair) showed the + combined-entry bundle is CONSISTENTLY SLOWER than this @fusion/core-only + baseline — warm median real +29.1% slower, import-phase aggregate + +74.0% slower, holding across every pair (not within this host's noise + band, unlike FN-7670's inconclusive result). Working theory: funnelling + all 14 original relative-import sites through a `resolveId`-plugin + redirect to one large (2.3MB) synthetic `export *` file adds more + transform/resolution overhead than it saves, unlike the @fusion/core + bundle's plain `resolve.alias` (a single fixed target, no per-specifier + plugin hook). NOT landed; wiring fully reverted to this @fusion/core- + only state (both the engine-graph scans and the combined-entry builder + were removed from scripts/build-engine-core-gate-bundle.mjs, and the + resolveId plugin was removed from this file — full diff in FN-7673's + git history). This lever (bundling the @fusion/engine relative-import + graph for the engine-core gate, in either a 14-file or single-combined- + entry shape) is now considered CLOSED — do not re-attempt without new + evidence changing the underlying cost model. See FN-7673's task docs + document for the full A/B data, the mock-boundary risk finding (a + combined-entry design broke a shared-test-helper vi.mock in a way + FN-7670's per-root design never could), and the closure rationale. */ alias: { "@fusion/core": resolve(__dirname, "../core/.gate-bundle/core.mjs"),