Add test illustrating how much better testing errors in React 19 is

Author: eps1lon

package.json

@@ -58,7 +58,7 @@
     "kcd-scripts": "^13.0.0",
     "npm-run-all": "^4.1.5",
     "react": "^18.3.1",
-    "react-dom": "^18.3.0",
+    "react-dom": "^18.3.1",
     "rimraf": "^3.0.2",
     "typescript": "^4.1.2"
   },

src/__tests__/error-handlers.js

@@ -1,3 +1,5 @@
+/* eslint-disable jest/no-if */
+/* eslint-disable jest/no-conditional-in-test */
 /* eslint-disable jest/no-conditional-expect */
 import * as React from 'react'
 import {render, renderHook} from '../'
@@ -6,6 +8,28 @@ const isReact19 = React.version.startsWith('19.')
 
 const testGateReact19 = isReact19 ? test : test.skip
 
+test('render errors', () => {
+  function Thrower() {
+    throw new Error('Boom!')
+  }
+
+  if (isReact19) {
+    expect(() => {
+      render(<Thrower />)
+    }).toThrow('Boom!')
+  } else {
+    expect(() => {
+      expect(() => {
+        render(<Thrower />)
+      }).toThrow('Boom!')
+    }).toErrorDev([
+      'Error: Uncaught [Error: Boom!]',
+      // React retries on error
+      'Error: Uncaught [Error: Boom!]',
+    ])
+  }
+})
+
 test('onUncaughtError is not supported in render', () => {
   function Thrower() {
     throw new Error('Boom!')

tests/toWarnDev.js

@@ -115,7 +115,7 @@ const createMatcherFor = (consoleMethod, matcherName) =>
         // doesn't match the number of arguments.
         // We'll fail the test if it happens.
         let argIndex = 0
-        format.replace(/%s/g, () => argIndex++)
+        String(format).replace(/%s/g, () => argIndex++)
         if (argIndex !== args.length) {
           lastWarningWithMismatchingFormat = {
             format,