Support React 19

[meritmalling]

Updating @flatfile/react for React 19 Support

Overview

This document outlines the steps required to update the @flatfile/react package to support React 19 while maintaining backwards compatibility where possible.

Current State

• Current React support: ^16.0.0 || ^17.0.0 || ^18.0.0
• Build system: Rollup + TypeScript
• Testing: Jest with React Testing Library

Required Changes

1. Package.json Updates

{
  "peerDependencies": {
    "react": "^16.0.0 || ^17.0.0 || ^18.0.0 || ^19.0.0",
    "react-dom": "^16.0.0 || ^17.0.0 || ^18.0.0 || ^19.0.0"
  },
  "devDependencies": {
    "@types/react": ">=16.9.0 <20.0.0",
    "@types/react-dom": ">=16.9.0 <20.0.0"
  }
}

2. TypeScript Configuration

• Review and update tsconfig.json if needed for React 19 JSX transformations
• Ensure JSX runtime compatibility

3. Testing Updates

• Update testing-library/react to latest version
• Review and update test configurations for React 19 compatibility

4. Code Review Areas

Key areas to review for React 19 compatibility:

1. useEffect and useLayoutEffect usage in:

   • FlatfileProvider.tsx
   • useFlatfile.ts
   • Other hooks

2. Event handling in:

   • EmbeddedIFrameWrapper
   • Space components
   • Event listeners

3. React.FC usage and component types

4. Test to determine others

[Sjohnson-OR]

@flatfile/listener type conflicts when using plugins with @flatfile/react

We're upgrading to React 19 and encountering TypeScript errors due to @flatfile/listener being bundled in multiple places:

Even though all are version 1.1.2, TypeScript sees them as incompatible types because they're from different paths. This causes errors like:

Using yarn resolutions to force a single version doesn't fully resolve the issue since @flatfile/embedded-utils bundles its own copy.

Current workaround: We're using // @ts-nocheck at the file level.

Suggestion: Could @flatfile/embedded-utils and @flatfile/react use @flatfile/listener as a peer dependency instead of bundling it?