From 6fbb0128006471b255f411f8a60151f46ee32872 Mon Sep 17 00:00:00 2001
From: Kentaro Wakayama <kentaro@codersociety.com>
Date: Wed, 5 Aug 2026 02:25:28 +0200
Subject: [PATCH] test(import-map): stop racing wall time in preloader capacity
 tests

`modules/import-map/preloader ... does not miss capacity released before
a waiter observes its signal` failed five times today in `coverage shard
4/8`, each time with:

  RangeError: Import-map preloader load timed out

It ejected veryfront-code#3365 from the merge queue and failed CI on
#3364 and #3369. It passes on re-run every time, and 3/3 locally.

`loadTimeoutMs` arms a real `setTimeout`, not the injected `now` clock.
These tests deliberately hold a load unresolved across the whole test
body to exercise capacity accounting, so a short timeout is racing wall
time. Shard 4/8 runs 200+ files in parallel with coverage instrumentation
and an 8GB heap, and the event loop can stall past the deadline. The
timer then rejects a load the test never intended to time out.

Give the three tests whose subject is not the timeout a delay far beyond
any plausible stall, behind a named constant so the reason survives.
Tests that do exercise timeout behavior keep their own small values.

Verified the mechanism rather than assuming it: setting the constant to
1ms reproduces the exact CI failure, and restoring it passes 47 steps.

Fixes veryfront-issue-inbox#364.
---
 src/modules/import-map/preloader.test.ts | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/modules/import-map/preloader.test.ts b/src/modules/import-map/preloader.test.ts
index 35d3c9cf9f..78625e91cc 100644
--- a/src/modules/import-map/preloader.test.ts
+++ b/src/modules/import-map/preloader.test.ts
@@ -18,6 +18,13 @@ import type { RuntimeAdapter } from "#veryfront/platform/adapters/base.ts";
 import { MAX_TIMER_DELAY_MS } from "#veryfront/utils/constants/limits.ts";
 import type { ImportMapConfig } from "./types.ts";
 
+/**
+ * `loadTimeoutMs` arms a real `setTimeout`, not the injected `now` clock, so
+ * tests holding a load unresolved race wall time and flake under CI load. Tests
+ * that do exercise timeout behavior keep their own small values.
+ */
+const TIMEOUT_NOT_UNDER_TEST_MS = 600_000;
+
 function createMinimalAdapter(): RuntimeAdapter {
   return {
     fs: {
@@ -1135,7 +1142,7 @@ describe("modules/import-map/preloader", () => {
         maxProjects: 2,
         maxVariantsPerProject: 1,
         ttlMs: 1_000,
-        loadTimeoutMs: 1_000,
+        loadTimeoutMs: TIMEOUT_NOT_UNDER_TEST_MS,
         loadImportMap: () => {
           const load = createDeferred<ImportMapConfig>();
           loads.push(load);
@@ -1223,7 +1230,7 @@ describe("modules/import-map/preloader", () => {
         maxProjects: 2,
         maxVariantsPerProject: 2,
         ttlMs: 1_000,
-        loadTimeoutMs: 1_000,
+        loadTimeoutMs: TIMEOUT_NOT_UNDER_TEST_MS,
         loadImportMap: () => {
           const load = createDeferred<ImportMapConfig>();
           loads.push(load);
@@ -1296,7 +1303,7 @@ describe("modules/import-map/preloader", () => {
         maxProjects: 1,
         maxVariantsPerProject: 2,
         ttlMs: 1_000,
-        loadTimeoutMs: 10_000,
+        loadTimeoutMs: TIMEOUT_NOT_UNDER_TEST_MS,
         now: () => {
           if (releaseDuringAdmission && admissionClockReads++ === 0) {
             loads[0]!.resolve({ imports: { source: "a" } });