fix(build): let the published package use Deno's own Deno global

[kojiwakayama]

Symptom

The CLI was entirely non-functional under Deno, even though
https://veryfront.com/docs/code/getting-started/installation documents
deno add npm:veryfront as a supported install path.

$ deno run -A npm:veryfront@0.1.1229 dev --port 3795

✗ [unknown-error] Unknown/unclassified error
  Detail: Cannot read properties of null (reading 'fd')
  Suggestion: Check logs for more details

The same project ran fine under Node. Not a regression — 0.1.1228 was also
broken under Deno, with a different message.

Root cause

The boundary reported unknown-error and dropped the original stack. Logging
the raw throwable in the published package gives the real one:

TypeError: Cannot read properties of null (reading 'fd')
    at Object.listen (node_modules/@deno/shim-deno/dist/deno/stable/functions/listen.js:44:64)
    at isPortAvailable (node_modules/veryfront/esm/cli/commands/dev/port-fallback.js:38:26)
    at clearLocalCachesIfPortFree (node_modules/veryfront/esm/cli/commands/dev/command.js:95:16)

dnt emits npm/esm/_dnt.shims.js as an unconditional re-export:

import { Deno } from "@deno/shim-deno";
export { Deno } from "@deno/shim-deno";

So every framework module that touches Deno.* got the Node
reimplementation — including when Deno itself was executing the package. The
shim's Deno.listen builds a node:net server and immediately reads
server._handle.fd:

const server = createServer();
const waitFor = new Promise((resolve) => server.listen(port, hostname, resolve));
// server._handle.fd is assigned immediately on .listen()
const listener = new Listener(server._handle.fd, /* … */);

That assumption does not hold on Deno's node compatibility layer, where
_handle is null. isPortAvailable is the first thing dev does, so the
process died before the server bound. Any port-binding command (dev,
start, …) hit the same wall.

Fix

Patch the generated shim in postBuild, right beside the existing
process.argv[1] fix, so it defers to the host runtime's own Deno and keeps
@deno/shim-deno as the fallback for Node and Bun:

import { Deno as dntShimDeno } from "@deno/shim-deno";
const dntNativeDeno = globalThis.Deno;
export const Deno = typeof dntNativeDeno?.version?.deno === "string"
    ? dntNativeDeno
    : dntShimDeno;

The first-party extension packages build through dnt with the same
shims: { deno: true } config and carry an identical shim file, so they get
the same patch.

patchDntDenoShim fails closed: if dnt's output shape ever changes, the root
build throws rather than silently shipping the broken shim again.

Verification against the published repro

Negative control, published 0.1.1229 — deno run -A npm:veryfront@0.1.1229 dev --port 3795 in a veryfront init project outside the monorepo:

✗ [unknown-error] Unknown/unclassified error
  Detail: Cannot read properties of null (reading 'fd')

Same project, same command, with node_modules/veryfront replaced by this
branch's deno task build:npm output:

=== shim head of the package under test ===
import { Deno as dntShimDeno } from "@deno/shim-deno";
const dntNativeDeno = globalThis.Deno;

Veryfront (v0.1.1229)

  ✓ Ready in 1.0s
  http://veryfront.me:3795

--verbose confirms it now walks all the way through route discovery and
binds the port instead of aborting after "Using local filesystem (no proxy
mode)".

Tests

scripts/build/dnt-polyfill.test.ts (already in deno task test:scripts).
The tests evaluate the shim module for real, with @deno/shim-deno swapped
for a local stub, so they assert which Deno the module actually hands back
rather than matching on source text:

• unpatched DNT shims shadow the real Deno global (the bug being fixed) —
  pins the pre-fix behaviour; fails if the patch is ever dropped
• patchDntDenoShim makes the published shims prefer the real Deno global
• patchDntDenoShim keeps the shim fallback for runtimes without Deno
• idempotency, fail-closed, and no-op-when-absent cases

Confirmed red before the fix (does not provide an export named 'patchDntDenoShim'), green after.

Scope

Build-script only; no src/ or docs changes, so nothing needs to be checked
on the live docs site for this PR.

Summary by CodeRabbit

• Bug Fixes

  • Improved compatibility for generated packages running in environments with native Deno APIs.
  • Prevented generated compatibility shims from overriding available native functionality.
  • Added safer handling for missing, already-patched, or unexpected generated files.

• Tests

  • Expanded coverage for compatibility behavior, fallback handling, idempotent patching, and missing-output scenarios.

[coderabbitai]

📝 Walkthrough

Walkthrough

The change adds patchDntDenoShim, tests native-Deno preference and fallback behavior, and invokes the patcher in both npm build flows.

Changes

DNT shim patching

Layer / File(s)	Summary
Native-Deno shim patcher scripts/build/dnt-polyfill.ts	Adds patchDntDenoShim and its options type. The patcher replaces unconditional DNT shim exports, preserves native Deno, supports fallback behavior, and handles missing or unexpected output.
Shim patch validation scripts/build/dnt-polyfill.test.ts	Adds BDD-style tests for native-Deno preference, fallback behavior, idempotence, required failures, and skipped files.
npm build integration scripts/build/build-npm-dnt.ts, scripts/build/build-npm-extension-packages.ts	Invokes patchDntDenoShim while post-processing generated npm packages.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Sequence Diagram(s)

sequenceDiagram
  participant NpmBuild as npm build flow
  participant ShimPatcher as patchDntDenoShim
  participant GeneratedShim as _dnt.shims.js
  participant Runtime as Native Deno global
  participant Fallback as `@deno/shim-deno`

  NpmBuild->>ShimPatcher: patch generated shim
  ShimPatcher->>GeneratedShim: replace unconditional export
  GeneratedShim->>Runtime: use native Deno when available
  GeneratedShim->>Fallback: use fallback otherwise

Loading

Possibly related PRs

• veryfront/veryfront-code#3598: Both changes address DNT shim behavior and native Deno API usage.
• veryfront/veryfront-code#3599: Both changes prevent @deno/shim-deno from interfering with native Deno APIs.

Suggested reviewers: kwakayama

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: published packages now prefer Deno's native global.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/dx-20260811-r2-19

---

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[chatgpt-codex-connector]

💡 Codex Review

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Reviewed commit: bfb24177e4

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@scripts/build/build-npm-extension-packages.ts`:
- Line 93: Update the patchDntDenoShim call in the extension package build to
pass the required option, ensuring missing generated _dnt.shims.js output causes
the build to fail closed. Match the existing required-shim usage in
build-npm-dnt.ts.

🪄 Autofix

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 18f807c6-cefe-45b5-8c03-5bfb3b9e3be5

📥 Commits

Reviewing files that changed from the base of the PR and between 64d6850 and d715f8d.

📒 Files selected for processing (4)

• scripts/build/build-npm-dnt.ts
• scripts/build/build-npm-extension-packages.ts
• scripts/build/dnt-polyfill.test.ts
• scripts/build/dnt-polyfill.ts

[kwakayama]

No actionable findings found.

Evidence: scripts/build/dnt-polyfill.ts:11-19 preserves the Node/Bun shim fallback while selecting the native Deno namespace only for a real Deno runtime. The replacement is applied to the root artifact with a required shape guard at scripts/build/build-npm-dnt.ts:230-244, and to extension artifacts at scripts/build/build-npm-extension-packages.ts:91-93. Focused tests cover native selection, fallback, idempotence, and generated-shim drift at scripts/build/dnt-polyfill.test.ts:112-197.

Rubric	Score
Correctness	40/40
Tests	19/20
Reliability/security	15/15
Maintainability	14/15
Scope/docs	10/10
Total	98/100

Review-Gate:
Reviewer: Codex
Reviewed-SHA: d715f8d
Score: 98/100
Actionable-Findings: 0
Verdict: APPROVE