React 19 Compatibility: Resolve Connect(SettingsForm) defaultProps warning

[coder-karen]

Issue

With React 19, defaultProps will continue to be supported for class components (ref) and have been removed from function components in our codebase.

However a console warning exists on the Jetpack Settings page:

Warning: Connect(SettingsForm): Support for defaultProps will be removed from memo components in a future major release. Use JavaScript default parameters instead

The full stack trace, though hard to parse, indicates the issue is with the react-redux connect function and how we are using it.

react-dom.development.js:86 Warning: Connect(SettingsForm): Support for defaultProps will be removed from memo components in a future major release. Use JavaScript default parameters instead.
    at ConnectFunction (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:9281:68)
    at div
    at div
    at ThemeProvider (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:18910:3)
    at Settings (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:66197:1)
    at C (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:11976:37)
    at ConnectFunction (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:9281:68)
    at div
    at div
    at div
    at Main (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:54936:5)
    at C (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:11976:37)
    at http://localhost/wp-includes/js/dist/data.js?ver=6f178ef23ef546c51cae:4489:25
    at ConnectFunction (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:9281:68)
    at Route (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:11719:29)
    at Switch (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:11921:29)
    at Router (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:11338:30)
    at HashRouter (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:10812:35)
    at Provider (http://localhost/wp-content/plugins/jetpack/_inc/build/admin.js?ver=69be9abf13d65df6e8c0:8992:20)
    at div

The issue appears to be with the children passed into the ThemeProvider component in the Settings class - /projects/plugins/jetpack/_inc/client/settings/index.jsx - these all have a 'type' of Symbol(react.memo) when children is logged into the console.

Solution

On more investigation, it appears as though the issue is the SearchableModules component passed into ThemeProvider via Settings - SearchableModules uses defaultProps. None of the others do (and the 'type' mentioned above was a red flag).

Parent issue: #37951