feat(react): upgrade to React 19 and replace reactstrap with react-bo…

[sreeshanth-soma]

Motivation

React 19 removes findDOMNode, which reactstrap depends on internally through react-transition-group. This causes runtime crashes in generated applications whenever modals, dropdowns, collapses, or tooltips are rendered.

Rather than polyfilling findDOMNode back onto ReactDOM (the approach in #32473), this PR follows the maintainer consensus from @mshima, @mraible, and @DanielFran to replace reactstrap with react-bootstrap. react-bootstrap has native React 19 support, no dependency on deprecated APIs, and uses the same Bootstrap 5 CSS, so generated applications remain visually identical.

@DanielFran also noted the @neolution-ch/reactstrap fork as an alternative. react-bootstrap was chosen over it because it is a first-party project with a larger community and does not depend on deprecated React internals, making it the more sustainable long-term choice.

Changes

Dependencies

Package	Previous	Updated
react / react-dom	18.3.1	19.1.0
@types/react	18.3.12	19.1.6
@types/react-dom	18.3.1	19.1.6
reactstrap	9.2.3	removed
react-bootstrap	—	2.10.9

npm overrides were added for react-jhipster and react-redux-loading-bar to resolve their React 18 peer dependency declarations until they publish compatible releases.

React 19 breaking changes

• Replaced JSX.Element with React.JSX.Element in typings.d.ts.ejs, error-boundary-routes.spec.tsx.ejs, and private-route.spec.tsx.ejs (global JSX namespace removed in v19).
• Added non-null assertion to document.getElementById('root')! in index.tsx.ejs (stricter createRoot null handling).

Template migration

All 33 template files were migrated from reactstrap to react-bootstrap. The API differences handled include:

• Prop renames: color to variant on Button and Alert, color to bg on Badge, tag to as for polymorphic rendering, isOpen to show/in, toggle to onHide.
• Component replacements: NavbarToggler to NavbarToggle, UncontrolledDropdown to Dropdown, UncontrolledTooltip to OverlayTrigger + Tooltip, Input to FormControl.
• Modal changes: ModalHeader toggle={fn} to ModalHeader closeButton (close handler inherited from parent Modal's onHide), removed modalTransition/backdropTransition props.

Testing

• npm run ejslint passes with zero errors.
• Zero reactstrap references remain across all .ts, .json, and .ejs files in generators/react/.

Closes #28130

[sreeshanth-soma]

@mshima could you please approve the workflows so the checks can run

[mshima]

react-jhipster has a dependency on reactstrap, needs to be dropped or updated.

[sreeshanth-soma]

@mshima thank you for the suggestion. I checked the react-jhipster source and saw that JhiPagination, the Metrics components, and ValidatedForm still import from reactstrap.

Before we can merge this generator PR, those components in react-jhipster will need to be migrated to react-bootstrap (or drop the dependency).

Since getting this PR merged is blocking my work on the React 19 upgrade, I would be happy to open a PR on the react-jhipster repo to migrate those remaining components to react-bootstrap. Would you be open to a PR for that?

[mshima]

@sreeshanth-soma sure go ahead.

[sreeshanth-soma]

Hello @mshima, I have opened a PR on react-jhipster to replace reactstrap with react-bootstrap: jhipster/react-jhipster#104
Once published, I will bump the version here so CI can pass.

[sreeshanth-soma]

Hello @mshima
All checks are passing now. Ready for review whenever you get a chance. Thanks for the help with the typings and overrides fixes!

[mshima]

The menu needs adjusts:

reactstrap:

react-bootstrap:

[mshima]

@qmonmert can you take a look?
I've used the following command to test.

npx github:sreeshanth-soma/generator-jhipster#feat/react-19-react-bootstrap --defaults --client-framework react --dev-database-type h2Disk

[mraible]

I can hold the beta.4 release for this PR if you like.

[mshima]

IMO this is the way forward.
Merging.

[mshima]

@sreeshanth-soma thanks and great work.

[sreeshanth-soma]

Thank you @mshima! Really enjoyed working through this one, learned a lot in the process and appreciate all the guidance along the way.

[qmonmert]

Yes great work @sreeshanth-soma 👍

[sreeshanth-soma]

Yes great work @sreeshanth-soma 👍

Thank you @qmonmert!

[sreeshanth-soma]

Opencollective

@mshima claiming the bounty for this pr.
Thank you

[jdubois]

Approved. Than you @sreeshanth-soma !

[sreeshanth-soma]

Approved. Than you @sreeshanth-soma !

@jdubois thank you!

[mshima]

@sreeshanth-soma CI is failling on windows: https://github.com/hipster-labs/jhipster-daily-builds/actions/workflows/windows.yaml
At first sight doesn't look related but the timeline matches. Any idea?

[sreeshanth-soma]

@mshima yeah it's related, "react-jhipster": "github:jhipster/react-jhipster#main" breaks on windows because npm runs the prepare script on git deps, and the cleanup script does rimraf lib/*. The * is illegal in windows paths so rimraf throws EINVAL .

Quickest fix would be changing lib/* to just lib in react-jhipster's cleanup script, or publishing a new version to npm so we dont need the git URL at all.

Let me know if you would like me to open a PR on react-jhipster for the cleanup script fix, happy to do it.

[mshima]

@sreeshanth-soma would be great