fix(cli): probe dev ports without the dnt Deno shim - #3599

The symptom

On published 0.1.1229, veryfront dev never binds a port when the CLI runs on Deno — the Deno-global install (deno install -gArf npm:veryfront), deno run -A npm:veryfront dev, and the deno task dev that a --runtime deno scaffold prints as its own next step:

Veryfront (v0.1.1229)

✗ [unknown-error] Unknown/unclassified error

  Detail: Cannot read properties of null (reading 'fd')
  Suggestion: Check logs for more details

build, serve, routes and doctor all succeed under the same install. dev was the only command that reached the broken code, and the npm-global (Node) install of the identical version runs dev fine.

Root cause

The real stack, recovered by calling handleDevCommand directly under Deno against the published tarball:

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)

isPortAvailable branched on isDeno and then called the bare Deno.listen. In the npm build dnt rewrites every bare Deno to @deno/shim-deno — esm/_dnt.shims.js re-exports the shim unconditionally, so the shim wins even when a genuine Deno global is right there. That shim's Node-backed listen() does:

const waitFor = new Promise((resolve) => server.listen(port, hostname, resolve));
// @ts-expect-error undocumented socket._handle property
const listener = new Listener(server._handle.fd, …);

server._handle is assigned synchronously by Node's listen(), but not by Deno's node-compat layer, so it is still null on that line. The one branch written for Deno was the one branch Deno could not execute.

The repo already knows this hazard — cli/auth/callback-server.ts reaches the real namespace via self ("Access native Deno.serve via self to bypass dnt shim transform"), and getNativeDeno() in src/platform/compat/http/native-response.ts documents it. port-fallback.ts, which was written to copy that callback server's fallback, missed it.

The fix

Probe with node:net on every runtime and delete the Deno branch. This function already used node:net on Node; it is one path now, it behaves identically on Deno, and it cannot reach the shim. Verified on all four runtime shapes the CLI ships in: Deno source, deno compile binary, npm-on-Node, npm-on-Deno.

Regression test

cli/commands/dev/port-fallback.test.ts stands a throwing Deno.listen into the ambient namespace — the shim reproduced in-process, same TypeError: Cannot read properties of null (reading 'fd') — and asserts the probe still reports a held port busy and a free port free. It fails on main at port-fallback.ts:41 with exactly the published error, and passes with this change.

Proof against the published artifact, not just the tests

The finding's own command, re-run against veryfront@0.1.1229 with only this function transplanted into the installed tree:

What this does not fix

With the port crash gone, veryfront dev under Deno binds and reports Ready, but page renders still fail with a separate Deno defect: the SSR module loader dynamic-importing generated .cache/veryfront-http-bundle/http-*.mjs throws TypeError: Loading unprepared module: …, so / returns 500 (Node returns 200 on the identical project). That is a different failure in a different subsystem and belongs to the open "CLI is entirely non-functional under the Deno runtime" reports — deliberately out of scope here rather than folded into this change.

Also from the originating finding, and deliberately unchanged: the published package declaring 7 of the 20 @veryfront/ext-* specifiers its runtime references is policy, not a packaging bug — rootNpm in src/extensions/first-party-defaults.ts keeps credentialed, native and output-changing integrations out of the root dependency set, and first-party-import.ts now degrades with an install hint instead of dying. No live doc page needs to change for this PR.

Summary by CodeRabbit

• Bug Fixes

  • Improved development server port detection across supported runtimes.
  • Port availability checks now reliably identify occupied and available ports without depending on ambient runtime behavior.

• Tests

  • Added regression coverage for port detection when the runtime’s default listener is unavailable.