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hyperframes/packages
JamesandClaude Opus 4.7 d54ad9ca19 refactor(engine): clamp warmupTicks to fixed iteration count, gated
Part of Phase 2 of the distributed rendering plan (determinism hardening).
See DISTRIBUTED-RENDERING-PLAN.md §5.2 (warmupTicks row) and §17.2 (gating
table).

The BeginFrame warmup loop in `initializeSession` is driven by wall-clock
during page load — different hosts accumulate different tick counts before
page-readiness completes. That shifts `session.beginFrameTimeTicks` and
yields non-byte-identical captures on distributed workers.

This change adds `lockWarmupTicks: boolean` (default false) to
`CaptureOptions`. When false, behavior is unchanged. When true, the loop
runs exactly `LOCKED_WARMUP_TICKS = 60` iterations regardless of page-load
wall clock, and `session.beginFrameTimeTicks` is computed from the
constant — pinning the baseline across hosts.

Refactoring:

  - Extract `driveWarmupTicks(options, state)` as a pure helper. Tests
    drive it with a stub `tick` callback and an injected `sleep`, so the
    iteration-count contract is unit-testable without real Chrome.
  - `initializeSession`'s warmup body is now a thin adapter that calls
    `driveWarmupTicks` with a CDP-backed tick.

Producer regression baselines remain byte-identical: the in-process
renderer never passes `lockWarmupTicks: true`. Phase 3 distributed
primitives will flip it true when launching chunk workers.

11 new unit tests at packages/engine/src/services/
frameCapture-warmupTicks.test.ts pin both branches (unlocked drifts with
simulated load time; locked produces identical counts).

This is part of a stack of 10 PRs; this is PR 3 of 10.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-13 04:36:11 +00:00
..
2026-05-13 01:35:21 +00:00
2026-05-13 01:35:21 +00:00