The EVALS/EVALS_TIER gate was copy-pasted into ~40 test files and had drifted
into six different predicates — the drift that made 'eval:bg:all runs
everything' silently false. test/helpers/e2e-gate.ts owns the semantics now:
describeE2ETier(tier) + e2eTierEnabled(tier), env read at call time, zero
side effects (the existing e2e-helpers module runs a ~30s claude ping at
import under EVALS=1, so the gate lives in its own module; purity is pinned
by tests that scan imports and comment-stripped source).
The unit matrix pins all four env combos — including EVALS=1 with EVALS_TIER
unset -> SKIP, the exact trap that made eval:bg:all a non-run. The
tier-alignment tripwire gains a second regex for the helper shape (old shape
still detected — stragglers can't hide), and the sharded paid runner's
PRE-SPAWN tier classifier learns the helper shape too: without that, every
gate-sharded run would have spawned all 28 periodic shards just to skip them,
each paying the e2e-helpers import ping (~15 min of dead wall clock in the
CI-blocking lane). Verified: gate runs exclude the 29 periodic files,
periodic excludes the 8 gate files — identical to pre-migration.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Garry Tan