feat(sandbox-mock): add @vercel/sandbox-mock package#245
Open
marc-vercel wants to merge 11 commits into
Open
Conversation
Add a drop-in mock of @vercel/sandbox backed by just-bash, with compile-time contracts that keep it at parity with the SDK: multi-user and group management, Command.durationMs, and the timeout/expiresAt semantics. Handler-backed detached commands return a working Command. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Contributor
|
The latest updates on your projects. Learn more about Vercel for GitHub.
|
|
Review the following changes in direct dependencies. Learn more about Socket for GitHub.
|
![vercel[bot]](https://avatars.githubusercontent.com/in/8329?s=60&v=4){kind=small}
- Dedupe concurrent resumes with a shared promise, matching the real SDK's resumePromise guard - Attach node-style code/syscall/path to filesystem errors so err.code === "ENOENT" checks behave like the real sandbox - Honor the resume param in Sandbox.get(), eagerly resuming stopped sandboxes and firing onResume like the real SDK - Validate the user exists in addUserToGroup (root and the default user are always allowed) Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Rewrite @vercel/sandbox-mock to re-export the real @vercel/sandbox classes and inject a mocked fetch, instead of reimplementing the SDK surface. An in-memory MockServer serves the /v2/sandboxes HTTP contract with command execution via just-bash, so commands, filesystem, snapshots, forking, and multi-user/group management all exercise the real SDK code — eliminating drift and the compile-time conformance machinery. Also fix @vercel/sandbox: Snapshot.get now forwards a custom fetch (WithFetchOptions), matching Snapshot.list/tree. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Keep @vercel/sandbox-mock and @vercel/sandbox on the same version so customers install a mock whose features match the SDK. Group the two as a fixed changesets set (they always bump together), align the mock's initial version to the SDK's 2.5.0, and add a test that errors if the versions drift. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Combine the two changesets added by this PR (the sandbox-mock addition and the Snapshot.get fetch-forwarding fix that enables it) into one entry. Also stop the mock's `@vercel/sandbox` peerDependency from forcing a major bump on every SDK release: with the fixed group, that major propagated to `@vercel/sandbox` too. Only bump peer-dependents when the new version falls outside the existing range, so both release as a minor (2.6.0). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Fold the Snapshot.get fetch-forwarding note into the sandbox-mock changeset so this PR carries a single entry, and only bump peer-dependents when the release falls outside the existing range — otherwise the mock's `@vercel/sandbox` peer forces a major that the fixed group propagates to the SDK. Both now release together as a minor (2.6.0). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
resetHandlers() wiped the baseline handlers to [], breaking the documented MSW-style pattern where defaults are registered once and resetHandlers() only drops per-test use() overrides. It now restores the setupSandbox baseline. Also document that handlers bind at sandbox start (register before create) and that a command() regex matches only its first literal command name. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
marc-vercel
marked this pull request as ready for review
July 13, 2026 14:55
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 free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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.
Testing code that uses
@vercel/sandboxmeans provisioning real sandboxes — slow, network-bound, and requiring credentials. In order to do that, customers must mock the whole Sandbox object, and they cannot run the integration tests until they go live (or they use real sandboxes).This new package,
@vercel/sandbox-mock, provides a mock that aims to run a local sandbox with some constraints. We are mocking the API layer, and instead of relying into the Vercel services, we mock it by usingjust-bash.We have also configured changeset to maintain version parity between
@vercel/sandboxand@vercel/sandbox-mock, to ensure that users and agents install the mock with the correct signatures.Testing
packages/vercel-sandbox-mock/tests/compat.test.tstest file which attempts to run the mock and real sandboxes, to ensure there is compatibility.🤖 Generated with Claude Code