CLI: Fix hidden output of CLI commands on Yarn 1

[kasperpeulen]

Closes SB-2060

What I did

On Yarn 1 (Classic) projects, runPackageCommand({ useRemotePkg: true, ... }) ignored every option except args. The caller's env, cwd, stdio, signal and ignoreError never reached executeCommand. This PR forwards them, the same way the npm, Yarn Berry, pnpm and Bun proxies already do. It also makes remote runs through npx (npm and Yarn 1) skip the npx download confirmation.

What a Yarn 1 user sees today

Since 10.5.0 the storybook binary downloads and runs @storybook/cli and create-storybook through this path (#35409). On Yarn 1 its stdio: 'inherit' is dropped, so the child runs with piped stdio and nothing it prints is shown:

Project	npx storybook@10.6.1 upgrade --help
npm	prints the help text
Yarn 1	prints nothing and exits 0
Yarn 1, 10.6.1 with ...options added to the npx call in dist	prints the help text

This applies to every command the dispatcher hands to those two packages (upgrade, add, automigrate, doctor, init, ...), unless the package is installed in the project at the same version. I measured --help only and did not run an interactive command.

The options were first dropped in #33888 (10.3.0), which added the npx branch.

The fix

Yarn Classic has no dlx, so the Yarn 1 proxy runs remote packages through npx. That branch built its own executeCommand call and dropped the options. The method now picks the runner and its args up front and makes one call, the way the Yarn Berry and pnpm proxies do, so the spread cannot be forgotten on one branch again:

 runPackageCommand({ args, useRemotePkg, ...options })
-  if useRemotePkg
-    executeCommand({ command: 'npx', args })
-  else
-    executeCommand({ command: 'yarn', args: ['exec', ...], ...options })
+  executeCommand({
+    ...options,
+    ...(useRemotePkg
+      ? { command: 'npx', args, env: { npm_config_yes: 'true', ...options.env } }
+      : { command: 'yarn', args: ['exec', ...] }),
+  })

How each proxy's remote path treats the caller's options:

Proxy	Remote runner	Options forwarded
npm	npx	yes
Yarn Berry	yarn dlx	yes
pnpm	pnpm dlx	yes
Bun	bunx	yes
Yarn 1	npx	no, until this PR

Why now

The upcoming skills install in storybook init / storybook upgrade (SB-2078, #36431) runs Vercel's skills CLI through this path. It passes cwd: <project root>, stdio: 'inherit', npm_config_yes: 'true' and, when needed, DISABLE_TELEMETRY: '1'. Without this fix, on Yarn 1 the skills would land in the current directory instead of the project root, the telemetry opt-out would not reach the CLI, and its output would be hidden. That PR does not include this fix, so merge this one first.

Existing callers that change behaviour on Yarn 1

Two callers already pass options over this path. On Yarn 1 those options were silently ignored until now, so after this PR these callers behave on Yarn 1 as they already do on every other package manager:

• CLI dispatcher: stdio: 'inherit' now applies, so the commands in the table above get the terminal.
• Playwright browser install during storybook init --skip-install with the Vitest addon: stdio: ['inherit', 'pipe', 'pipe'] and the abort signal behind "press c to abort" now apply. Stdout and stderr were already piped, so what changes is that the child reads from the terminal and that the abort reaches it.

Reading from the terminal has a side effect. When stdin is a terminal, npx asks "Ok to proceed?" before it downloads playwright, and the spinner shows only the first 25 characters of its output, so the install would wait on a question the user cannot read. npm projects already have this on next. The npm and Yarn 1 proxies now set npm_config_yes: 'true' on remote runs, so npx does not ask. That covers this caller and any later one, and a caller's own env still wins.

No caller is changed in this PR.

Evidence

A unit test drives the Yarn 1 remote path and asserts what reaches executeCommand:

runPackageCommand({ useRemotePkg: true, args, env: { SOME_VAR: '1' }, cwd: '/repo', stdio: 'inherit', signal, ignoreError: true })
expect executeCommand called with { command: 'npx', args, env: { npm_config_yes: 'true', SOME_VAR: '1' }, cwd, stdio, signal, ignoreError }

• Before: the test fails. executeCommand received only { command: 'npx', args }, with none of the caller's options.
• After: the test passes.

Running the real proxy against the built core, with the script from the manual testing section below:

before:  DISABLE_TELEMETRY= cwd=<the directory the script was started from>
after:   DISABLE_TELEMETRY=1 cwd=/private/tmp/sb2060-probe

The npx question, running a remote package that is not in the npx cache, with stdin a terminal and stdio: ['inherit', 'pipe', 'pipe']:

the call next makes on Yarn 1 (options dropped):  installs without asking
Yarn 1 proxy with only the options forwarded:      waits on "Ok to proceed? (y)"
this PR, Yarn 1 proxy:                             installs without asking
this PR, npm proxy:                                installs without asking

The package manager proxy tests and yarn nx check core pass.

Merge danger

Door: two-way. It is a small change to one method in each of two proxies, and reverting it restores the old behaviour exactly.

Blast radius: the remote-package path (npx) of the Yarn 1 and npm proxies. On Yarn 1 the two callers listed above now get the stdio and signal they already request. On npm the only change is npm_config_yes on remote runs; the dispatcher already passes --yes there. The other package managers and the non-remote paths are untouched.

Checklist for Contributors

Testing

The changes in this PR are covered in the following automated tests:

• stories
• unit tests
• integration tests
• end-to-end tests

Manual testing

Caution

This section is mandatory for all contributions. If you believe no manual test is necessary, please state so explicitly. Thanks!

The script forces the Yarn 1 proxy, so no Yarn 1 project is needed. It runs a remote package through npx and prints what the child process sees. It downloads semver, so it needs network access, and it uses a POSIX shell command, so run it on macOS or Linux.

1. Check out this branch, then run yarn and yarn nx compile core from the repository root.

2. Create code/sb2060-probe.mjs with this content:

   const { JsPackageManagerFactory } = await import('storybook/internal/common');
   const pm = JsPackageManagerFactory.getPackageManager({ force: 'yarn1' });
   const { stdout } = await pm.runPackageCommand({
     useRemotePkg: true,
     args: ['--yes', '-p', 'semver', '-c', 'echo "DISABLE_TELEMETRY=$DISABLE_TELEMETRY cwd=$(pwd)"'],
     env: { DISABLE_TELEMETRY: '1' },
     cwd: '/tmp/sb2060-probe',
     stdio: 'pipe',
   });
   console.log(stdout);

3. Run mkdir -p /tmp/sb2060-probe && cd code && node sb2060-probe.mjs.

4. Expect DISABLE_TELEMETRY=1 cwd=/private/tmp/sb2060-probe on macOS, or cwd=/tmp/sb2060-probe on Linux.

5. Optional: check out next, run yarn nx compile core again, and rerun the script. It prints an empty DISABLE_TELEMETRY= and the code/ directory as cwd.

6. Delete code/sb2060-probe.mjs.

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli-storybook/src/sandbox-templates.ts

• Declare whether manual QA will be needed for this PR during the next release, through qa:needed or qa:skip

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

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---

Walkthrough

Yarn1Proxy.runPackageCommand selects npx or yarn based on useRemotePkg and forwards execution options. Playwright installation now sets npm_config_yes in the command environment. Tests cover option forwarding and installation command options.

Changes

Package command options

Layer / File(s)	Summary
Unify command execution and verify options code/core/src/common/js-package-manager/Yarn1Proxy.ts, code/core/src/common/js-package-manager/Yarn1Proxy.test.ts	runPackageCommand selects npx with the original arguments or yarn with the exec arguments. Both paths receive the remaining execution options. Tests check remote option forwarding and use a shared resolved executeCommand mock for runScript.
Set Playwright install environment code/core/src/cli/AddonVitestService.ts, code/core/src/cli/AddonVitestService.test.ts	The Playwright installation command sets npm_config_yes to 'true'. Tests expect this environment option in ordinary, CI, macOS, and Windows cases.

Priority: ⬇️ Low

Merge Risk: ⚪ Minimal · up to 61c57

No concrete merge-blocking risk remains in the reviewed changes.

Security Architecture Review

Security architecture risk: 🔵 Low · up to 61c57

The change is narrow and preserves installation consent, package selection, and existing execution privileges. No newly exploitable security condition was established. Remote cancellation now reaches the child process, but cleanup and safe recovery after an interrupted browser or system-dependency installation remain unverified.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• inferred — The affected authority is package execution in the initiating CLI or CI environment, including browser installation and existing system-dependency behavior. Generic Yarn 1 callers can now influence remote execution through options they already supplied. Remote-package trust and access to that environment predate this PR; no additional service identity or tenant boundary was established by the scoped changes.

Trust Boundaries and Controls

• observed — npm_config_yes suppresses the downstream package-runner confirmation, but the existing Storybook installation decision remains before execution: the skip setting exits early, and otherwise confirmation or the caller’s explicit yes option is required. Package and argument selection remain fixed to Playwright Chromium installation rather than accepting an arbitrary package through this entrypoint.

Resilience and Maintainability Implications

• observed — Yarn 1 remote execution now forwards cancellation to the child process. The spinner distinguishes abort from failure and removes its abort listeners. ignoreError does not turn the returned asynchronous rejection into success. These controls support accurate terminal reporting, but do not prove cleanup or safe recovery of external partial-install state.

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Actionable comments posted: 2

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• 🪄 Fix CodeRabbit comments on this PR

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Inline comments:
In `@code/core/src/common/js-package-manager/Yarn1Proxy.test.ts`:
- Around line 89-90: Move the mockedExecuteCommand return-value setup out of the
test case and into beforeEach, then make the test assertions against
mockedExecuteCommand while preserving the existing mock behavior.
- Around line 87-110: Update the remote-path test for
Yarn1Proxy.runPackageCommand to include a signal and ignoreError in the input
options, then assert both are forwarded to executeCommand alongside the existing
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[storybook-app-bot]

Package Benchmarks

^{Commit: dedcc28, ran on 1 October 2026 at 11:41:43 UTC}

The following packages have significant changes to their size or dependencies:

@storybook/angular

	Before	After	Difference
Dependency count	186	186	0
Self size	240 KB	267 KB	🚨 +28 KB 🚨
Dependency size	31.61 MB	31.61 MB	0 B
Bundle Size Analyzer	Link	Link

@storybook/angular-vite

	Before	After	Difference
Dependency count	20	20	0
Self size	23.25 MB	23.28 MB	🚨 +28 KB 🚨
Dependency size	11.55 MB	11.55 MB	🎉 -18 B 🎉
Bundle Size Analyzer	Link	Link

@storybook/web-components-vite

	Before	After	Difference
Dependency count	6	6	0
Self size	19 KB	19 KB	0 B
Dependency size	413 KB	441 KB	🚨 +28 KB 🚨
Bundle Size Analyzer	Link	Link

@storybook/web-components

	Before	After	Difference
Dependency count	4	4	0
Self size	91 KB	118 KB	🚨 +28 KB 🚨
Dependency size	126 KB	126 KB	0 B
Bundle Size Analyzer	Link	Link

[kasperpeulen]

@coderabbitai full review

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[ghengeveld]

Thanks for the thorough description and the probe script, it made this really easy to follow. The Yarn 1 unification looks great to me. Left a few questions inline, mostly around where npm_config_yes lives and one small check on the cwd change. Nothing urgent, happy to approve once we land on those.