[core] V2: skip inline step execution when suspension also has a wait#1924
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Inline `await executeStep(...)` blocks the V2 handler for the full step duration, but `wait_completed` events are only created on the *next* loop iteration's "complete elapsed waits" pass. This breaks `Promise.race(step, sleep)` semantics whenever the sleep is shorter than the step — replay still picks the step because the sleep's wait_completed event hasn't been written yet. Reproducer (`sleepWinsRaceWorkflow`): a 1s sleep raced against a 10s step. Expected `'sleep'` to win; the runtime returned `'step'`. On the failing run, `wait_completed` was created at t=11.86s — right after `step_completed` — instead of at t≈2.74s when its `resumeAt` elapsed. Fix: in `runtime.ts`, gate the inline-step pick on the absence of a wait timeout. When `suspensionResult.timeoutSeconds !== undefined`, queue every pending step instead and return with the wait timeout. This lets the wait timer drive a continuation in parallel, matching V1's behavior where each step ran in a separate function invocation. Pure step suspensions (without waits) still benefit from inline execution. Test plan: - New e2e tests `sleepWinsRaceWorkflow` and `stepWinsRaceWorkflow` exercising `Promise.race` between a step function and `sleep()`, in both directions. - Verified locally against `nextjs-turbopack` workbench: both pass. Event log confirms `wait_completed` is now created on time (t≈1s after `wait_created`) rather than after the inline step. Eager-processing changelog updated with a "Mixed Suspensions" section describing the carve-out and its rationale. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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🦋 Changeset detectedLatest commit: ee02092 The changes in this PR will be included in the next version bump. This PR includes changesets to release 18 packages
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📊 Benchmark Results
workflow with no steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) workflow with 1 step💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) workflow with 10 sequential steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) workflow with 25 sequential steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) workflow with 50 sequential steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) Promise.all with 10 concurrent steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) Promise.all with 25 concurrent steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) Promise.all with 50 concurrent steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) Promise.race with 10 concurrent steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) Promise.race with 25 concurrent steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) Promise.race with 50 concurrent steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) workflow with 10 sequential data payload steps (10KB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) workflow with 25 sequential data payload steps (10KB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) workflow with 50 sequential data payload steps (10KB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) workflow with 10 concurrent data payload steps (10KB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) workflow with 25 concurrent data payload steps (10KB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) workflow with 50 concurrent data payload steps (10KB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) Stream Benchmarks (includes TTFB metrics)workflow with stream💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) stream pipeline with 5 transform steps (1MB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) 10 parallel streams (1MB each)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) fan-out fan-in 10 streams (1MB each)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) SummaryFastest Framework by WorldWinner determined by most benchmark wins
Fastest World by FrameworkWinner determined by most benchmark wins
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🧪 E2E Test Results✅ All tests passed Summary
Details by Category✅ ▲ Vercel Production
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✅ 🐘 Local Postgres
✅ 🪟 Windows
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May 5, 2026
Signed-off-by: Peter Wielander <mittgfu@gmail.com>
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* origin/main: [core] Skip inline step execution when suspension also has a wait (#1924) [errors] Replace chalk import in @workfow/errors with inline ANSI shim (#1915) Fix compatibility with Zod 4.4.x (#1902) Serialize `run_failed`/`step_failed` errors through serialization pipeline (#1851) tarballs: redesign preview tarballs index page (#1911) Remove extra changeset (#1922) Add stable Next.js eager and lazy test coverage (#1747) Enforce per-(run, correlation) uniqueness for entity-creating events in world-postgres (#1878) fix(world-vercel): add default request timeout to workflow-server HTTP calls (#1807)
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PR #1924 added the same sleep/step race workflows directly to main while this branch was open. The textual concat from `git merge` left both copies in 99_e2e.ts; this drops the duplicate set so the file matches origin/main verbatim and the e2e tests pick up the upstream definitions. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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…ignal * origin/main: [core] Skip inline step execution when suspension also has a wait (#1924) [errors] Replace chalk import in @workfow/errors with inline ANSI shim (#1915) Fix compatibility with Zod 4.4.x (#1902) Serialize `run_failed`/`step_failed` errors through serialization pipeline (#1851) tarballs: redesign preview tarballs index page (#1911) Remove extra changeset (#1922) Add stable Next.js eager and lazy test coverage (#1747) Enforce per-(run, correlation) uniqueness for entity-creating events in world-postgres (#1878) fix(world-vercel): add default request timeout to workflow-server HTTP calls (#1807) Allow disabling step sourcemap with new `sourcemap` option in builders (#1842) [ci] Enable Vercel-prod e2e for tanstack-start (#1904) web: configure vercelPreset() for Vercel deployments (#1815) [core] Combine flow+step bundle and process steps eagerly (#1338) [world-vercel] Revert stream close control framing (#1891) [tarballs] Use turbo to build workspace deps before packing (#1908) # Conflicts: # packages/core/src/runtime/step-handler.test.ts # packages/core/src/runtime/step-handler.ts # packages/core/src/runtime/suspension-handler.ts # packages/core/src/step.test.ts # packages/world-local/src/storage/events-storage.ts # packages/world-postgres/src/drizzle/migrations/meta/_journal.json
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* [e2e] Add step-vs-sleep race tests + dev-tmux skill Adds two race workflows (sleepWinsRaceWorkflow, stepWinsRaceWorkflow) that exercise Promise.race between a step function and a sleep call. The current `sleepWinsRaceWorkflow` test fails — surfacing how the replay engine resolves a previously-completed step instantly while sleep still has to elapse. Also adds a `dev-tmux` skill that documents the 3-pane tmux + portless setup for testing workflows interactively in a worktree alongside the observability UI. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * [workbench/nextjs-turbopack] Allow *.turbopack.localhost in dev Adds allowedDevOrigins entries so portless-style worktree-prefixed .localhost URLs (e.g. https://<branch>.turbopack.localhost) can hit HMR and dev-only endpoints without Next's cross-origin protection flooding the logs with warnings. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * Drop duplicate race workflows after merging main PR #1924 added the same sleep/step race workflows directly to main while this branch was open. The textual concat from `git merge` left both copies in 99_e2e.ts; this drops the duplicate set so the file matches origin/main verbatim and the e2e tests pick up the upstream definitions. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * [skills/dev-tmux] Narrow activation, robust pane IDs, statusline helper - Tighten activation phrases so the skill only fires for the specific portless+tmux setup it documents, not the generic "start the dev server" task. Addresses #1916 review. - Capture pane IDs at split time (-P -F '#{pane_id}') so the snippet works under both pane-base-index 0 and 1. Addresses Copilot review. - Add `statusline.sh` that filters `portless list` to the current worktree's routes and emits a one-line summary, plus instructions for wiring it into Claude Code's `statusLine.command`. - Bump version to 1.1. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * [skills/dev-tmux] Recommend primary-checkout path for statusline Worktrees get deleted, so wiring the statusline to a worktree path breaks the moment the worktree is removed. Update the skill and the script header to recommend pointing `statusLine.command` at the primary checkout (`$HOME/github/vercel/workflow/...`). The script itself is already worktree-aware via Claude's `workspace.current_dir` stdin JSON, so the same invocation surfaces routes for whichever worktree the session is in. Bump version to 1.2. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * [skills/dev-tmux] OSC 8 link statusline + worktree-named tmux session - Statusline overlay now renders `[dev] · [obs] · tmux:<prefix>`, with the bracketed labels emitted as OSC 8 hyperlinks (clickable in any modern terminal) styled cyan + underline so they stand out. Replaces the old long-URL form that was hard to scan and click. - Add a tmux-session indicator: shown when a session named exactly the worktree prefix exists (uses `tmux has-session -t =<prefix>` for exact matching). - Change the skill's tmux session naming convention from the fixed `workflow-dev` to `<worktree-prefix>` (basename of the branch — same string portless uses as the subdomain prefix). This lets the statusline locate the session deterministically and lets multiple worktrees run dev sessions concurrently without manual disambiguation. - Bump skill to v1.3. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * [skills/dev-tmux] Statusline: print full `tmux attach -t <name>` command Replaces the abbreviated `tmux:<prefix>` indicator with the full copy-paste-ready `tmux attach -t <prefix>` invocation. Saves a step when grabbing the session from another shell. Bump skill to v1.4. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * [skills/dev-tmux] Brighter statusline + Nerd Font icons - Drop the dim styling that made the overlay hard to read; use bold bright cyan + underline for links and bold bright green for the tmux command. - Add Nerd Font glyphs: for dev, for obs, for the tmux copy-paste hint. Falls back to box-drawing if the font lacks Nerd Font ranges; layout is unaffected. - Visual differentiation: cyan + underline = clickable hyperlink; green = copy this command. Bump skill to v1.5. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * [skills/dev-tmux] Restore Nerd Font icons via Unicode escapes The copy glyph in `emit_tmux` was a literal Nerd Font byte embedded in the printf string and got stripped during a prior rewrite. Promote all three icons (rocket / graph / copy) to top-level shell variables that use \uHHHH-equivalent UTF-8 escapes, so the source survives editor round-trips that don't preserve Private Use Area code points. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> * [skills/internal-dev-workbench] Rename from dev-tmux, set author + reset version - Rename `skills/dev-tmux/` → `skills/internal-dev-workbench/` to make the name self-explanatory about the skill's scope (an internal contributor's local dev workbench, not a generic tmux helper). - Author: Pranay Prakash. Version: 0.1 (first release of the skill). - Update internal references in SKILL.md and statusline.sh accordingly. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Summary
Fix
Promise.race(step, sleep)semantics in V2 mixed suspensions: when a workflow suspension contains both pending steps and at least one wait (sleep), the runtime now queues every step instead of executing one inline.Inline `await executeStep(...)` blocks the V2 handler for the full step duration, but `wait_completed` events are only created on the next loop iteration's "complete elapsed waits" pass. So if the sleep is shorter than the step, the wait timer never fires on time — replay just sees `step_completed` first and `Promise.race` resolves with the step. A 1s sleep racing a 10s step would silently resolve to the step.
This restores V1's behavior, where each step ran in a separate function invocation and the wait timer drove a parallel queue continuation.
Reproducer (failing test from #1916)
`sleepWinsRaceWorkflow`: a 1s sleep raced against a 10s step. Expected `'sleep'` to win.
Event log on the failing run, before the fix:
After the fix, `wait_completed` lands at t≈1s after `wait_created` and the run completes with `'sleep'` in ~1s.
Change
One-liner in `packages/core/src/runtime.ts`:
```ts
const inlineStep =
suspensionResult.timeoutSeconds === undefined
? ownedPendingSteps[0]
: undefined;
```
The existing "queue every pending step except the inline one" loop and the `if (!inlineStep)` early-return already handle the `undefined` case correctly.
What about hooks?
Audited every flavor of suspension. Step + wait is the only fully-broken combination.
Step + hook works on all first-party worlds today. A consistent follow-up would extend the same carve-out to `hasPendingHooks`, but it would require a new field in `SuspensionHandlerResult` and isn't strictly necessary — happy to do that as a follow-up if desired.
Test plan
Docs
`docs/content/docs/changelog/eager-processing.mdx` "Mixed Suspensions" section rewritten to describe the carve-out and explicitly call out the `Promise.race(step, sleep)` race-semantics motivation.
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