fix: render Streamdown on React 18 via useContext

package.json

@@ -77,8 +77,8 @@
     "vitest": "^4.1.10"
   },
   "peerDependencies": {
-    "react": "^19.0.0",
-    "react-dom": "^19.0.0"
+    "react": ">=18.0.0",
+    "react-dom": ">=18.0.0"
   },
   "engines": {
     "node": ">=22.0.0"

src/profiler/StreamdownProfilerProvider.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { createContext, memo, type PropsWithChildren, use } from 'react';
+import { createContext, memo, type PropsWithChildren, useContext } from 'react';
 
 import { type StreamdownProfiler } from './profiler';
 
@@ -12,12 +12,14 @@ export interface StreamdownProfilerProviderProps {
 
 export const StreamdownProfilerProvider = memo<PropsWithChildren<StreamdownProfilerProviderProps>>(
   ({ children, profiler = null }) => {
-    return <StreamdownProfilerContext value={profiler}>{children}</StreamdownProfilerContext>;
+    return (
+      <StreamdownProfilerContext.Provider value={profiler}>{children}</StreamdownProfilerContext.Provider>
+    );
   },
 );
 
 StreamdownProfilerProvider.displayName = 'StreamdownProfilerProvider';
 
 export const useStreamdownProfiler = () => {
-  return use(StreamdownProfilerContext);
+  return useContext(StreamdownProfilerContext);
 };

src/profiler/profiler.test.ts

@@ -1,6 +1,9 @@
+import { createElement, type ReactNode } from 'react';
+import { renderHook } from '@testing-library/react';
 import { describe, expect, it, vi } from 'vitest';
 
 import { createStreamdownProfiler } from './profiler';
+import { StreamdownProfilerProvider, useStreamdownProfiler } from './StreamdownProfilerProvider';
 
 describe('createStreamdownProfiler', () => {
   it('aggregates render and animation samples into a snapshot', () => {
@@ -166,3 +169,16 @@ describe('createStreamdownProfiler', () => {
     }
   });
 });
+
+describe('useStreamdownProfiler', () => {
+  it('reads the profiler through useContext so React 18 can render Streamdown', () => {
+    const profiler = createStreamdownProfiler({ label: 'react-18', notifyIntervalMs: 0 });
+    const { result } = renderHook(() => useStreamdownProfiler(), {
+      wrapper: ({ children }: { children: ReactNode }) =>
+        createElement(StreamdownProfilerProvider, { profiler }, children),
+    });
+
+    expect(result.current).toBe(profiler);
+    expect(result.current?.getSnapshot().label).toBe('react-18');
+  });
+});