[Snyk] Security upgrade diff from 7.0.0 to 8.0.3

[rubenfiszel]

Snyk has created this PR to fix 1 vulnerabilities in the npm dependencies of this project.

Snyk changed the following file(s):

• frontend/package.json
• frontend/package-lock.json

Vulnerabilities that will be fixed with an upgrade:

	Issue
	Regular Expression Denial of Service (ReDoS) SNYK-JS-DIFF-14917201

---

Important

• Check the changes in this PR to ensure they won't cause issues with your project.
• Max score is 1000. Note that the real score may have changed since the PR was raised.
• This PR was automatically created by Snyk using the credentials of a real user.

---

Note: You are seeing this because you or someone else with access to this repository has authorized Snyk to open fix PRs.

For more information:
🧐 View latest project report
📜 Customise PR templates
🛠 Adjust project settings
📚 Read about Snyk's upgrade logic

---

Learn how to fix vulnerabilities with free interactive lessons:

🦉 Regular Expression Denial of Service (ReDoS)

[cloudflare-workers-and-pages]

Deploying windmill with    Cloudflare Pages

Latest commit:	6d51274
Status:	✅  Deploy successful!
Preview URL:	https://fd7b837e.windmill.pages.dev
Branch Preview URL:	https://snyk-fix-fa709d7dc47ea0296b1.windmill.pages.dev

View logs

[claude]

Claude finished @rubenfiszel's task in 1m 17s —— View job

---

PR Review: Security Upgrade for diff Package

• Analyze the PR changes
• Review security implications
• Check for breaking changes
• Provide feedback

---

Summary

This PR upgrades the diff npm package from version 7.0.0 to 8.0.3 to fix a Regular Expression Denial of Service (ReDoS) vulnerability (SNYK-JS-DIFF-14917201).

Changes Review

Files Changed:

• frontend/package.json - Updated diff dependency from ^7.0.0 to ^8.0.3
• frontend/package-lock.json - Updated lockfile to reflect the new version (8.0.3)

Usage Analysis

The diff package is used in 3 files in the copilot/chat feature:

File	Import	Usage
frontend/src/lib/components/copilot/chat/monaco-adapter.ts:1	diffLines	Compares code changes in the AI chat editor
frontend/src/lib/components/copilot/chat/context.ts:4	type Change	Type import only
frontend/src/lib/components/copilot/chat/ContextManager.svelte.ts:4	diffLines	Creates diff context for saved/deployed versions

Security Assessment

✅ Vulnerability Fixed: The ReDoS vulnerability allowed attackers to cause denial of service through carefully crafted input strings that trigger exponential backtracking in regex patterns.

✅ Impact Scope: The diff package is used in the AI copilot chat feature for comparing code changes. While user input could potentially reach this code path, fixing this vulnerability is important for defense in depth.

Breaking Changes Assessment

⚠️ Major Version Upgrade: This is a major version upgrade (7.x → 8.x), which typically indicates breaking changes.

However, reviewing the codebase usage:

• diffLines function: This function signature has remained stable across versions
• Change type: The type interface for diff results is also stable

The codebase only uses:

1. diffLines(oldStr, newStr) - Standard usage
2. Change type with properties added, removed, count, value

These are core APIs that have remained consistent. The major version bump was likely due to internal changes, TypeScript improvements, or other API changes that don't affect this codebase's usage.

Recommendation

✅ LGTM - Approve this PR

This security fix should be merged:

1. Fixes a real ReDoS vulnerability
2. The specific APIs used (diffLines and Change type) are stable
3. Low risk of breaking changes for the actual usage in this codebase
4. The @types/diff package (v7.0.1) in devDependencies may need updating to v8.x if type errors occur during build, but this typically provides backwards compatibility

Suggested Follow-up

Consider running the frontend build/tests to verify compatibility:

cd frontend && npm install && npm run check

---

Testing Instructions

To verify the AI copilot diff functionality still works correctly after this upgrade:

Navigate to the Script Editor in the Windmill app, open the AI Copilot chat panel (Cmd/Ctrl+K), and have the AI make a code change. The diff preview showing additions (green) and deletions (red) should display correctly. Also test comparing the current code with a previously deployed version by clicking on the diff context option if available.