chore: upgrade Yarn to 4.16.0

[Mrtenz]

Summary

Migrates from Yarn classic to Yarn 4.16.0 to align with the module template:

• Yarn is activated via Corepack from the packageManager field; .yarnrc is replaced by .yarnrc.yml (template defaults verbatim).
• Install-script approval moves to the LavaMoat yarn-plugin-allow-scripts, checked in under .yarn/plugins/. @lavamoat/allow-scripts bumps to ^3.0.4 and @lavamoat/preinstall-always-fail to ^2.0.0 to match the plugin. The setup script is removed.
• build-lint-test.yml: both jobs gain corepack enable, the install becomes yarn install --immutable, and the explicit yarn allow-scripts step is dropped.

dist/index.js is regenerated; the bundled output differs slightly because ncc inlines a few helpers differently after the lockfile migration, but the source is unchanged.

Four browserslist-ecosystem transitives (pulled in via @babel/core for Jest's transforms) were briefly pinned with resolutions to dodge the 3-day npmMinimalAgeGate during the initial install, then dropped once the lockfile settled.

The bigger template gaps (workflow restructure, yarn.config.cjs, engines.node bump) remain out of scope.

[socket-security]

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	@​lavamoat/​preinstall-always-fail@​1.0.0 ⏵ 2.1.1			+5
	@​lavamoat/​allow-scripts@​1.0.6 ⏵ 3.4.3	+1		+10

View full report

[socket-security]

Warning

MetaMask internal reviewing guidelines:

• Do not ignore-all
• Each alert has instructions on how to review if you don't know what it means. If lost, ask your Security Liaison or the supply-chain group
• Copy-paste ignore lines for specific packages or a group of one kind with a note on what research you did to deem it safe.
  @SocketSecurity ignore npm/PACKAGE@VERSION

Action	Severity	Alert  (click "▶" to expand/collapse)
Warn		Install-time scripts: npm @lavamoat/preinstall-always-fail during preinstall Install script: preinstall Source: echo "Don't run npm lifecycle scripts by default! Create a .yarnrc or .npmrc and set enableScripts: false. Then, whitelist them with @lavamoat/allow-scripts" && exit 1 From: package.json → npm/@lavamoat/preinstall-always-fail@2.1.1 ℹ Read more on: This package | This alert | What is an install script? Next steps: Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at support@socket.dev. Suggestion: Packages should not be running non-essential scripts during install and there are often solutions to problems people solve with install scripts that can be run at publish time instead. Mark the package as acceptable risk. To ignore this alert only in this pull request, reply with the comment @SocketSecurity ignore npm/@lavamoat/preinstall-always-fail@2.1.1. You can also ignore all packages with @SocketSecurity ignore-all. To ignore an alert for all future pull requests, use Socket's Dashboard to change the triage state of this alert.
Warn		Potential code anomaly (AI signal): npm @npmcli/git is 100.0% likely to have a medium risk anomaly Notes: The code reads the user's git configuration and applies defaults to streamline automation, notably by auto-accepting new SSH host keys and bypassing prompts. This reduces friction for automation but lowers interactive security. Not inherently malicious, but the default behavior should be clearly documented and optionally opt-in or restricted per-project to mitigate potential risk. Confidence: 1.00 Severity: 0.60 From: ? → npm/@lavamoat/allow-scripts@3.4.3 → npm/@npmcli/git@7.0.2 ℹ Read more on: This package | This alert | What is an AI-detected potential code anomaly? Next steps: Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at support@socket.dev. Suggestion: An AI system found a low-risk anomaly in this package. It may still be fine to use, but you should check that it is safe before proceeding. Mark the package as acceptable risk. To ignore this alert only in this pull request, reply with the comment @SocketSecurity ignore npm/@npmcli/git@7.0.2. You can also ignore all packages with @SocketSecurity ignore-all. To ignore an alert for all future pull requests, use Socket's Dashboard to change the triage state of this alert.
Warn		Potential code anomaly (AI signal): npm function-bind is 100.0% likely to have a medium risk anomaly Notes: The code is a standard Function.prototype.bind polyfill implementation. It carefully handles this binding, constructor behavior, and argument binding without introducing observable malicious behavior. The dynamic Function constructor is used as part of a legitimate polyfill technique and does not indicate an attack by itself in this context. Confidence: 1.00 Severity: 0.60 From: ? → npm/@lavamoat/allow-scripts@3.4.3 → npm/eslint-plugin-node@11.1.0 → npm/jest@29.7.0 → npm/eslint-plugin-import@2.23.3 → npm/function-bind@1.1.2 ℹ Read more on: This package | This alert | What is an AI-detected potential code anomaly? Next steps: Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at support@socket.dev. Suggestion: An AI system found a low-risk anomaly in this package. It may still be fine to use, but you should check that it is safe before proceeding. Mark the package as acceptable risk. To ignore this alert only in this pull request, reply with the comment @SocketSecurity ignore npm/function-bind@1.1.2. You can also ignore all packages with @SocketSecurity ignore-all. To ignore an alert for all future pull requests, use Socket's Dashboard to change the triage state of this alert.
Warn		Potential code anomaly (AI signal): npm node-gyp is 100.0% likely to have a medium risk anomaly Notes: The code is a legitimate Windows registry query and filesystem readability utility, with no inherent malware or backdoors. Primary security concerns are data exposure through verbose logging and the potential misuse of reg.exe with untrusted inputs. Mitigations include restricting input sources, redacting sensitive outputs in logs, and ensuring callers handle registry data securely. Overall security risk is moderate due to sensitive operations and logging exposure, but no active malicious behavior detected. Confidence: 1.00 Severity: 0.60 From: ? → npm/@lavamoat/allow-scripts@3.4.3 → npm/ts-jest@29.4.11 → npm/@vercel/ncc@0.36.1 → npm/jest@29.7.0 → npm/node-gyp@12.4.0 ℹ Read more on: This package | This alert | What is an AI-detected potential code anomaly? Next steps: Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at support@socket.dev. Suggestion: An AI system found a low-risk anomaly in this package. It may still be fine to use, but you should check that it is safe before proceeding. Mark the package as acceptable risk. To ignore this alert only in this pull request, reply with the comment @SocketSecurity ignore npm/node-gyp@12.4.0. You can also ignore all packages with @SocketSecurity ignore-all. To ignore an alert for all future pull requests, use Socket's Dashboard to change the triage state of this alert.
Warn		Potential code anomaly (AI signal): npm resolve is 100.0% likely to have a medium risk anomaly Notes: This manifest uses a non-registry, relative-path dependency ('resolve': '../../../') which is a significant supply-chain risk because it allows arbitrary local code to be pulled in and executed without registry protections. Combined with the 'lerna bootstrap' postinstall script (which can trigger other lifecycle scripts across the monorepo), this setup increases the chance of untrusted code execution and other malicious behavior. Inspect the target of the relative path, all bootstrap-linked packages, and any lifecycle scripts before running npm install in an untrusted environment. Confidence: 1.00 Severity: 0.60 From: ? → npm/@lavamoat/allow-scripts@3.4.3 → npm/eslint-plugin-node@11.1.0 → npm/jest@29.7.0 → npm/eslint-plugin-import@2.23.3 → npm/resolve@1.22.10 ℹ Read more on: This package | This alert | What is an AI-detected potential code anomaly? Next steps: Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at support@socket.dev. Suggestion: An AI system found a low-risk anomaly in this package. It may still be fine to use, but you should check that it is safe before proceeding. Mark the package as acceptable risk. To ignore this alert only in this pull request, reply with the comment @SocketSecurity ignore npm/resolve@1.22.10. You can also ignore all packages with @SocketSecurity ignore-all. To ignore an alert for all future pull requests, use Socket's Dashboard to change the triage state of this alert.
Warn		Potential code anomaly (AI signal): npm signal-exit is 100.0% likely to have a medium risk anomaly Notes: The code represents a legitimate signal-exit instrumentation module intended to provide robust exit handling and lifecycle hooks. It does not introduce executable malware or data exfiltration in this fragment. However, it significantly alters process termination behavior and could cause compatibility issues or subtle bugs if used alongside other exit-handling code in extensions. Overall, this is a non-malicious yet potentially risky integration point that should be reviewed for compatibility with other modules in the extension. Confidence: 1.00 Severity: 0.60 From: ? → npm/@lavamoat/allow-scripts@3.4.3 → npm/signal-exit@4.1.0 ℹ Read more on: This package | This alert | What is an AI-detected potential code anomaly? Next steps: Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at support@socket.dev. Suggestion: An AI system found a low-risk anomaly in this package. It may still be fine to use, but you should check that it is safe before proceeding. Mark the package as acceptable risk. To ignore this alert only in this pull request, reply with the comment @SocketSecurity ignore npm/signal-exit@4.1.0. You can also ignore all packages with @SocketSecurity ignore-all. To ignore an alert for all future pull requests, use Socket's Dashboard to change the triage state of this alert.
Warn		Potential code anomaly (AI signal): npm tar is 100.0% likely to have a medium risk anomaly Notes: This module acts as a standard tar extraction wrapper using synchronous and asynchronous code paths. There is no evident malicious activity within this fragment. Security risk hinges on the behavior of the Unpack/UnpackSync implementation and how tar entries are written to disk (e.g., path traversal). No hardcoded secrets or network calls are present here. Recommend ensuring tar extraction handles path traversal and destination path sanitization in Unpack, and consider validating opt.file presence and type before streaming. Confidence: 1.00 Severity: 0.60 From: ? → npm/@lavamoat/allow-scripts@3.4.3 → npm/ts-jest@29.4.11 → npm/@vercel/ncc@0.36.1 → npm/jest@29.7.0 → npm/tar@7.5.16 ℹ Read more on: This package | This alert | What is an AI-detected potential code anomaly? Next steps: Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at support@socket.dev. Suggestion: An AI system found a low-risk anomaly in this package. It may still be fine to use, but you should check that it is safe before proceeding. Mark the package as acceptable risk. To ignore this alert only in this pull request, reply with the comment @SocketSecurity ignore npm/tar@7.5.16. You can also ignore all packages with @SocketSecurity ignore-all. To ignore an alert for all future pull requests, use Socket's Dashboard to change the triage state of this alert.

Ignoring alerts on:

• read-cmd-shim@4.0.0
• undici@6.26.0
• glob@13.0.6
• write-file-atomic@5.0.1
• npm-normalize-package-bin@3.0.1
• lru-cache@11.5.1

View full report

[Mrtenz]

@SocketSecurity ignore npm/glob@13.0.6
@SocketSecurity ignore npm/lru-cache@11.5.1

False positive.

@SocketSecurity ignore npm/undici@6.26.0

Network access expected.

@SocketSecurity ignore npm/npm-normalize-package-bin@3.0.1
@SocketSecurity ignore npm/read-cmd-shim@4.0.0
@SocketSecurity ignore npm/write-file-atomic@5.0.1

New author is ok.