**Related issue:** Closes#48943
# Checklist for submitter
If some of the following don't apply, delete the relevant line.
- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/guides/committing-changes.md#changes-files)
for more information.
- [x] Input data is properly validated, `SELECT *` is avoided, SQL
injection is prevented (using placeholders for values in statements), JS
inline code is prevented especially for url redirects, and untrusted
data interpolated into shell scripts/commands is validated against shell
metacharacters.
- [x] Timeouts are implemented and retries are limited to avoid infinite
loops
## Testing
- [x] Added/updated automated tests
- [x] QA'd all new/changed functionality manually
## Summary
Adds unit test coverage for external library upgrades that had no
automated tests:
- **DOMPurify** (`ClickableUrls_xss.tests.tsx`): 5 XSS sanitization
tests (script injection, javascript: in href, event handlers, iframe,
URL preservation)
- **react-markdown + remark-gfm** (`FleetMarkdown.tests.tsx`): 9
rendering tests (plain text, bold/italic, links, lists, GFM tables,
strikethrough, code blocks, inline code)
- **sonner** (`ToastNotification.tests.tsx`): 9 notify API tests
(success/error creation, empty-message fallback, custom id, dismiss,
batch, HTTP status label, axios response unwrap)
These gaps were identified through a comprehensive audit of all ~353
direct dependencies across Go and frontend. The Go backend has excellent
coverage (669+ test files). The frontend now has 333+ test files
covering all runtime libraries except 2 that are untestable at unit
level (systray GUI, sockjs WebSocket).
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Tests**
* Added coverage confirming potentially unsafe HTML and links are
sanitized before rendering, including protection against script,
`javascript:` URLs, and injected content.
* Added tests validating Markdown rendering for plain text, links,
fenced code blocks, and inline code.
* Added coverage for toast notifications, including success/error flows,
batching, dismissal, fallback messaging, ID handling, and mapping
response details.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** Resolves #
# Checklist for submitter
If some of the following don't apply, delete the relevant line.
- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/guides/committing-changes.md#changes-files)
for more information.
## Testing
- [x] Added/updated automated tests
- [x] QA'd all new/changed functionality manually
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **New Features**
* Redesigned in-app notifications with a new toast-based UI style.
* Error messages are now dismissible and expandable to reveal detailed
server response information.
* Success and error notifications now appear consistently across the
application with improved visibility.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Sharon Katz