feat: React 19

package.json

@@ -17,8 +17,7 @@
   "repository": "https://github.com/pmndrs/its-fine",
   "license": "MIT",
   "files": [
-    "dist/*",
-    "src/*"
+    "dist/*"
   ],
   "type": "module",
   "types": "./dist/index.d.ts",
@@ -27,23 +26,22 @@
   "react-native": "./dist/index.js",
   "sideEffects": false,
   "devDependencies": {
-    "@types/node": "^18.7.15",
-    "@types/react": "^18.0.17",
-    "@types/react-test-renderer": "^18.0.0",
-    "react": "^18.2.0",
-    "react-nil": "^1.2.0",
-    "react-test-renderer": "^18.2.0",
-    "rimraf": "^3.0.2",
-    "suspend-react": "^0.0.8",
-    "typescript": "^4.7.4",
-    "vite": "^3.1.0",
-    "vitest": "^0.23.1"
+    "@types/node": "^22.13.4",
+    "@types/react": "^19.0.0",
+    "@types/react-test-renderer": "^19.0.0",
+    "react": "^19.0.0",
+    "react-nil": "^2.0.0",
+    "react-test-renderer": "^19.0.0",
+    "rimraf": "^6.0.1",
+    "typescript": "^5.7.3",
+    "vite": "^6.1.0",
+    "vitest": "^3.0.6"
   },
   "dependencies": {
-    "@types/react-reconciler": "^0.28.0"
+    "@types/react-reconciler": "^0.28.9"
   },
   "peerDependencies": {
-    "react": ">=18.0"
+    "react": "^19.0.0"
   },
   "scripts": {
     "build": "rimraf dist && vite build && tsc",

tests/index.test.tsx → src/index.test.tsx

@@ -1,6 +1,6 @@
 import * as React from 'react'
 import { describe, expect, it } from 'vitest'
-import { type NilNode, type HostContainer, act, render, createPortal } from 'react-nil'
+import { type NilNode, type HostContainer, render, createPortal } from 'react-nil'
 import { create } from 'react-test-renderer'
 import {
   type Fiber,
@@ -11,7 +11,14 @@ import {
   useNearestParent,
   useContextBridge,
   FiberProvider,
-} from '../src'
+} from './index'
+
+declare global {
+  var IS_REACT_ACT_ENVIRONMENT: boolean
+}
+
+// Let React know that we'll be testing effectful components
+global.IS_REACT_ACT_ENVIRONMENT = true
 
 interface ReactProps {
   key?: React.Key
@@ -25,7 +32,7 @@ interface PrimitiveProps {
 
 type Primitive = NilNode<PrimitiveProps>
 
-declare global {
+declare module 'react' {
   namespace JSX {
     interface IntrinsicElements {
       primitive: ReactProps & PrimitiveProps
@@ -41,6 +48,8 @@ class ClassComponent extends React.Component<{ children?: React.ReactNode }> {
   }
 }
 
+const act = React.act
+
 describe('useFiber', () => {
   it('throws when used outside of a FiberProvider', async () => {
     let threw = false

src/index.tsx

@@ -10,10 +10,10 @@ import type ReactReconciler from 'react-reconciler'
  *
  * @see https://github.com/facebook/react/issues/14927
  */
-const useIsomorphicLayoutEffect =
-  typeof window !== 'undefined' && (window.document?.createElement || window.navigator?.product === 'ReactNative')
-    ? React.useLayoutEffect
-    : React.useEffect
+const useIsomorphicLayoutEffect = /* @__PURE__ */ (() =>
+  typeof window !== 'undefined' && (window.document?.createElement || window.navigator?.product === 'ReactNative'))()
+  ? React.useLayoutEffect
+  : React.useEffect
 
 /**
  * Represents a react-internal Fiber node.
@@ -75,18 +75,7 @@ function wrapContext<T>(context: React.Context<T>): React.Context<T> {
   }
 }
 
-const error = console.error
-console.error = function () {
-  const message = [...arguments].join('')
-  if (message?.startsWith('Warning:') && message.includes('useContext')) {
-    console.error = error
-    return
-  }
-
-  return error.apply(this, arguments as any)
-}
-
-const FiberContext = wrapContext(React.createContext<Fiber>(null!))
+const FiberContext = /* @__PURE__ */ wrapContext(/* @__PURE__ */ React.createContext<Fiber>(null!))
 
 /**
  * A react-internal {@link Fiber} provider. This component binds React children to the React Fiber tree. Call its-fine hooks within this.
@@ -153,10 +142,10 @@ export function useContainer<T = any>(): T | undefined {
  */
 export function useNearestChild<T = any>(
   /** An optional element type to filter to. */
-  type?: keyof JSX.IntrinsicElements,
-): React.MutableRefObject<T | undefined> {
+  type?: keyof React.JSX.IntrinsicElements,
+): React.RefObject<T | undefined> {
   const fiber = useFiber()
-  const childRef = React.useRef<T>()
+  const childRef = React.useRef<T>(undefined)
 
   useIsomorphicLayoutEffect(() => {
     childRef.current = traverseFiber<T>(
@@ -176,10 +165,10 @@ export function useNearestChild<T = any>(
  */
 export function useNearestParent<T = any>(
   /** An optional element type to filter to. */
-  type?: keyof JSX.IntrinsicElements,
-): React.MutableRefObject<T | undefined> {
+  type?: keyof React.JSX.IntrinsicElements,
+): React.RefObject<T | undefined> {
   const fiber = useFiber()
-  const parentRef = React.useRef<T>()
+  const parentRef = React.useRef<T>(undefined)
 
   useIsomorphicLayoutEffect(() => {
     parentRef.current = traverseFiber<T>(
@@ -196,6 +185,11 @@ export type ContextMap = Map<React.Context<any>, any> & {
   get<T>(context: React.Context<T>): T | undefined
 }
 
+const REACT_CONTEXT_TYPE = Symbol.for('react.context')
+
+const isContext = <T,>(type: unknown): type is React.Context<T> =>
+  type !== null && typeof type === 'object' && '$$typeof' in type && type.$$typeof === REACT_CONTEXT_TYPE
+
 /**
  * Returns a map of all contexts and their values.
  */
@@ -207,13 +201,9 @@ export function useContextMap(): ContextMap {
   contextMap.clear()
   let node = fiber
   while (node) {
-    if (node.type && typeof node.type === 'object') {
-      // https://github.com/facebook/react/pull/28226
-      const enableRenderableContext = node.type._context === undefined && node.type.Provider === node.type
-      const context = enableRenderableContext ? node.type : node.type._context
-      if (context && context !== FiberContext && !contextMap.has(context)) {
-        contextMap.set(context, React.useContext(wrapContext(context)))
-      }
+    const context = node.type
+    if (isContext(context) && context !== FiberContext && !contextMap.has(context)) {
+      contextMap.set(context, React.use(wrapContext(context)))
     }
 
     node = node.return!

tsconfig.json

@@ -4,7 +4,7 @@
     "target": "es6",
     "module": "ESNext",
     "lib": ["ESNext", "dom"],
-    "moduleResolution": "node",
+    "moduleResolution": "bundler",
     "esModuleInterop": true,
     "jsx": "react",
     "pretty": true,
@@ -13,5 +13,6 @@
     "emitDeclarationOnly": true,
     "forceConsistentCasingInFileNames": true
   },
-  "include": ["src/**/*"]
+  "include": ["src/**/*"],
+  "exclude": ["src/**/*.test.*"]
 }

vite.config.ts

@@ -1,14 +1,8 @@
-/// <reference types="vitest" />
-import * as path from 'path'
+import * as path from 'node:path'
 import { defineConfig } from 'vite'
 
 export default defineConfig({
-  test: {
-    dir: 'tests',
-    setupFiles: 'tests/setupTests.ts',
-  },
   build: {
-    minify: false,
     sourcemap: true,
     target: 'es2018',
     lib: {
@@ -18,11 +12,6 @@ export default defineConfig({
     },
     rollupOptions: {
       external: (id: string) => !id.startsWith('.') && !path.isAbsolute(id),
-      treeshake: false,
-      output: {
-        preserveModules: true,
-        sourcemapExcludeSources: true,
-      },
     },
   },
 })