Add support for React 19

[cacabo]

Environment

• Package version(s): "@blueprintjs/core": "^5.11.0"
• Browser and OS versions: n/a

Feature request

I want to leverage React 19 in my app which uses Blueprint in order to benefit from the React compiler, other performance improvements, and the new hooks.

Blueprint currently requires:

npm error peer react@"^16.8 || 17 || 18" from @blueprintjs/[email protected]

I can use the beta compiler runtime until Blueprint can upgrade:

// package.json
{
    // ...
    "dependencies": {
        "react": "^18.3.1",
        "react-compiler-runtime": "^19.0.0-beta-63b359f-20241101",
        // ...
    }
}

Examples

[bofa]

I would love react 19 support to be able to leverage the improved custom elements integration.

[smeng9]

Currently there are still a lot of use cases of ReactDOM.render in the codebase which react 19 dropped support of. All of these need to be migrated to use createRoot

[bradchristensen]

Currently there are still a lot of use cases of ReactDOM.render in the codebase which react 19 dropped support of. All of these need to be migrated to use createRoot

I just had a quick scan through the repository and it looks like all the references to ReactDOM.render are either in tests/documentation, or they can be replaced on your app side if you provide a domRenderer prop to the relevant component. So I don't think this is a blocker, but it would be nice if Blueprint could either update to use the updated createRoot method by default, or provide an automatic backwards-compatible implementation.