Files
hyperframes/packages/cli
Miguel Ángel 74149e249a fix(cli): keep a live preview's ownership record and stop past a bad one (#3308)
* fix(cli): keep a live preview's ownership record and stop past a bad one

A missed liveness probe is not proof the preview is gone — a server blocked on
a Puppeteer capture answers nothing for a second or two — but any miss retired
the session record, and the record carries the only PID-reuse guard `--stop`
has. Reproduced by SIGSTOPping a managed preview and running `--status`: the
record was deleted and never came back, leaving every later stop to fall
through to an unauthenticated port scan with no ownership proof at all. Only a
wrapper process that is provably gone now retires a record.

That record gains a process-birth token so a recycled PID reads as a different
process, and it is written through a temp file and renamed — every reader
deletes it when it fails to parse, so a torn read would otherwise destroy a
live server's proof of ownership.

Two failure-propagation bugs in the stop path: `--kill-all` collected the
first unprovable record's exception and abandoned every server after it, so
they were left running AND unreported; and a replacement refused to launch
when the server it was replacing had already exited on its own, which is the
goal state rather than a failure. `--list` now shows managed sessions ahead of
whatever else answers the scan.

* fix(cli): keep a record whose identity lookup gave no answer, not a different one

Review blocker. The keep-alive path this PR adds could still retire a LIVE
record — through a different door than the one it closed.

`processIdentity` catches every failure into `null`, and on two of three
platforms that failure is a subprocess timeout on a live process: the win32
`Win32_Process` CIM query and the POSIX `ps -o lstart=` both run on a 2 s
budget, under exactly the load that made the HTTP probe miss in the first
place. A `null` compared unequal to the saved token, so the record was deleted
and `wrapperIdentity` — the only PID-reuse guard `--stop` has — was gone for
good. Only Linux, reading /proc directly, was reliable.

No answer is now distinguished from a different answer: the PID is checked with
`kill(pid, 0)` first, which asks the kernel without signalling and treats EPERM
as alive. A PID nothing can signal is gone and retires the record with no
subprocess at all; a signalable PID whose token cannot be read keeps it. Only a
token that comes back and differs retires it.

That ordering also answers the `--list` note: the identity subprocess no longer
runs for the stale records that made it slow, so the N x 2 s worst case is gone
along with the timeouts that fed the bug.

Verified by mutation: restoring the old "no answer means gone" behaviour reds
the new case. Also clean up the temp file when a rename fails, rather than
orphaning it in the session directory.

* test(cli): assert only what the birth-token lookup actually guarantees

`captures a stable birth token for the current process` made two assertions
that a lookup allowed to fail cannot support. `processIdentity` returns null
whenever the lookup cannot be completed — not only when the process is absent —
and on Windows and macOS it shells out to PowerShell or `ps` on a 2 s budget
that a cold CI runner routinely outruns.

Both failed on windows-latest, in sequence: first `.toMatch()` received null,
and once that was guarded, `expect(second).toBe(first)` compared a null from the
cold first spawn against a token from the warm second one.

Two lookups can disagree for exactly one reason — one of them failed — so
stability is only assertable across two successful ones. The token itself
cannot change between calls; it is a birth timestamp and the process did not
restart. `processIdentity(-1)` stays unconditional: the guard rejects it before
any subprocess runs.

The strict shape assertion moves to a Linux-only case, where /proc is read
directly with no subprocess and null is genuinely not allowed — keeping the
guarantee on the one platform that can honour it rather than dropping it
everywhere. Callers already depend on this contract: `wrapperProcessIsAlive`
treats null as "no answer" rather than "gone" precisely because it is reachable.
2026-08-18 19:50:02 -04:00
..
2026-08-18 11:11:46 -04:00

hyperframes

CLI for creating, previewing, and rendering HTML video compositions.

Install

npm install -g hyperframes

Or use directly with npx:

npx hyperframes <command>

Requirements: Node.js >= 22, FFmpeg

Commands

init

Scaffold a new Hyperframes project from a template:

npx hyperframes init my-video
cd my-video

preview

Start the live preview studio in your browser:

npx hyperframes preview
# Studio running at http://localhost:3002

npx hyperframes preview --port 4567

render

Render a composition to MP4. Run from the project directory; the positional argument is the project directory (not a file), so render the project's index.html directly, or point at a specific composition file with -c:

npx hyperframes render -o output.mp4
npx hyperframes render -c ./my-composition.html -o output.mp4

lint

Validate your Hyperframes HTML:

npx hyperframes lint ./my-composition
npx hyperframes lint ./my-composition --json      # JSON output for CI/tooling
npx hyperframes lint ./my-composition --verbose   # Include info-level findings

By default only errors and warnings are shown. Use --verbose to also display informational findings (e.g., external script dependency notices). Use --json for machine-readable output with errorCount, warningCount, infoCount, and a findings array.

compositions

List compositions found in the current project:

npx hyperframes compositions

benchmark

Run rendering benchmarks:

npx hyperframes benchmark ./my-composition.html

doctor

Check your environment for required dependencies (Chrome, FFmpeg, Node.js):

npx hyperframes doctor

browser

Manage the bundled Chrome/Chromium installation:

npx hyperframes browser

info

Print version and environment info:

npx hyperframes info

docs

Open the documentation in your browser:

npx hyperframes docs

upgrade

Check for updates and show upgrade instructions:

npx hyperframes upgrade
npx hyperframes upgrade --check --json  # machine-readable for agents

Documentation

Full documentation: hyperframes.heygen.com/packages/cli