Uh oh!
There was an error while loading. Please reload this page.
Fix Next lazy discovery step imports - #2263
Merged
Merged
Conversation
Contributor
🦋 Changeset detectedLatest commit: 268861a The changes in this PR will be included in the next version bump. This PR includes changesets to release 16 packages
Not sure what this means? Click here to learn what changesets are. Click here if you're a maintainer who wants to add another changeset to this PR |
Contributor
🧪 E2E Test Results✅ All tests passed Summary
Details by Category✅ ▲ Vercel Production
✅ 💻 Local Development
✅ 📦 Local Production
✅ 🐘 Local Postgres
✅ 🪟 Windows
✅ 📋 Other
|
Contributor
📊 Benchmark Results
workflow with no steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) | Express | Nitro workflow with 1 step💻 Local Development
▲ Production (Vercel)
🔍 Observability: Nitro | Express | Next.js (Turbopack) workflow with 10 sequential steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Nitro | Next.js (Turbopack) | Express workflow with 25 sequential steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Express | Nitro | Next.js (Turbopack) workflow with 50 sequential steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) | Nitro | Express Promise.all with 10 concurrent steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) | Nitro | Express Promise.all with 25 concurrent steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Nitro | Next.js (Turbopack) | Express Promise.all with 50 concurrent steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) | Express | Nitro Promise.race with 10 concurrent steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Express | Next.js (Turbopack) | Nitro Promise.race with 25 concurrent steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Nitro | Next.js (Turbopack) | Express Promise.race with 50 concurrent steps💻 Local Development
▲ Production (Vercel)
🔍 Observability: Nitro | Next.js (Turbopack) | Express workflow with 10 sequential data payload steps (10KB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Nitro | Next.js (Turbopack) | Express workflow with 25 sequential data payload steps (10KB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Nitro | Next.js (Turbopack) | Express workflow with 50 sequential data payload steps (10KB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Nitro | Express | Next.js (Turbopack) workflow with 10 concurrent data payload steps (10KB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Express | Nitro | Next.js (Turbopack) workflow with 25 concurrent data payload steps (10KB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Nitro | Next.js (Turbopack) | Express workflow with 50 concurrent data payload steps (10KB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) | Express | Nitro Stream Benchmarks(includes TTFB metrics)workflow with stream💻 Local Development
▲ Production (Vercel)
🔍 Observability: Express | Nitro | Next.js (Turbopack) stream pipeline with 5 transform steps (1MB)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Express | Nitro | Next.js (Turbopack) 10 parallel streams (1MB each)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Next.js (Turbopack) | Express | Nitro fan-out fan-in 10 streams (1MB each)💻 Local Development
▲ Production (Vercel)
🔍 Observability: Nitro | Express | Next.js (Turbopack) SummaryFastest Framework by WorldWinner determined by most benchmark wins
Fastest World by FrameworkWinner determined by most benchmark wins
Column Definitions
Worlds:
|
ijjkforce-pushed
the
ijjk/next-lazy-discovery-step-imports
branch
from
June 5, 2026 05:22
a92ab93 to
1cffb60ComparevercelBottemporarily deployed
to
Preview – example-nextjs-workflow-turbopack
June 5, 2026 06:30
Inactive
ijjkforce-pushed
the
ijjk/next-lazy-discovery-step-imports
branch
from
June 5, 2026 06:30
6c131fa to
263b0aaCompareVaguelySerious
approved these changes
Jun 5, 2026
VaguelySerious
left a comment
Member
There was a problem hiding this comment.
AI review: no blocking issues.
Validated beyond the PR's build check by building the turbopack workbench in lazy-discovery mode and inspecting the real output:
- Generated flow route emits no separate
__step_registrations.jsbundle; discovered step sources are imported directly as side-effect imports, and the@workflow/aiworkspace source resolves to itsdistoutput via the newsrc→distmapping. - Confirmed the registration survives Next's production tree-shaking: the compiled server chunk contains
globalThis[...].set("step//@workflow/ai/agent@<ver>//closeStream", ...), so the bare side-effect import is retained and the step registers at runtime. The PR'spnpm buildalone doesn't prove this. - Verified the manifest/runtime stepId invariant: the manifest is generated from the source file while the route imports the built dist file, but the stepId is derived from package name + version + function name (not the file path), so both agree. This is what makes the src→dist swap safe.
- Added local-only tests for the two otherwise-uncovered branches in the dist mapping:
.mts→.mjs, and the dist-missing fallback (correctly falls back to importing the source rather than a non-existent dist path). Both pass. - Unit tests and
index/buildersuites pass locally; full CI matrix (turbopack + webpack, lazy on/off, dev/prod/postgres) is green.
| ); | ||
| return importSpecifiers | ||
| .map((specifier) => `import ${JSON.stringify(specifier)};`) |
There was a problem hiding this comment.
AI Review: Note
These are bare side-effect imports, so retention depends on the bundler not tree-shaking side-effect-only imports. App-local files and workspace packages with no sideEffects field are safe — I verified Turbopack keeps the @workflow/ai registration in the compiled server bundle.
The gap: a workspace step package that declares "sideEffects": false could have its generated import "...dist/x.js" legally pruned by webpack, silently dropping step registration. The previous combined bundle guarded against this by importing a named __steps_registered binding and doing void __steps_registered. Non-blocking, but worth either a comment noting the constraint or a sideEffects: false fixture package in the webpack lazy-discovery e2e to lock in coverage.
Contributor
No backport to This commit fixes V2-specific Next.js lazy discovery behavior that exists only on To override, re-run the Backport to stable workflow manually via |
This was referenced Jun 5, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for freeto join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Testing