From 269bd40a953a5339ad47c643f9b9dbce88ab878d Mon Sep 17 00:00:00 2001
From: "Sebastian \"Sebbie\" Silbermann" <sebastian.silbermann@vercel.com>
Date: Wed, 26 Aug 2026 19:24:58 +0200
Subject: [PATCH] [test] Remove the custom `toThrow` override for legacy V8
 error messages (#37384)

The custom `toThrow` override in `scripts/jest/matchers/toThrow.js`
wrapped the built-in matcher to rewrite the pre-Node-17 V8 error message
format ("Cannot read property 'x' of undefined") into the modern one
("Cannot read properties of undefined (reading 'x')"), so the test suite
could run on Node 12 to 16.

On the Node versions this repo runs on (20 per `.nvmrc`, 24 in CI), V8
only ever produces the modern format, so the override is a passthrough.

Mostly removing this because the custom matcher deep-imports
`expect/build/toThrowMatchers`, which no longer resolves on Jest 30
because each Jest package is now bundled into a single file, so this
removal unblocks the Jest 30 upgrade stacked on top.

Co-authored-by: Claude Code (kimi-k3[1m]) <noreply@anthropic.com>
---
 .../__tests__/ReactServerRendering-test.js    | 16 +++---
 .../ReactHooksWithNoopRenderer-test.js        |  2 +-
 scripts/jest/matchers/toThrow.js              | 50 -------------------
 scripts/jest/setupTests.js                    |  1 -
 .../spec-equivalence-reporter/setupTests.js   |  1 -
 5 files changed, 9 insertions(+), 61 deletions(-)
 delete mode 100644 scripts/jest/matchers/toThrow.js

diff --git a/packages/react-dom/src/__tests__/ReactServerRendering-test.js b/packages/react-dom/src/__tests__/ReactServerRendering-test.js
index c071d3ff47b5..4a78a17117af 100644
--- a/packages/react-dom/src/__tests__/ReactServerRendering-test.js
+++ b/packages/react-dom/src/__tests__/ReactServerRendering-test.js
@@ -147,7 +147,7 @@ describe('ReactDOMServer', () => {
     it('should throw with silly args', () => {
       expect(
         ReactDOMServer.renderToString.bind(ReactDOMServer, {x: 123}),
-      ).toThrowError(
+      ).toThrow(
         'Objects are not valid as a React child (found: object with keys {x})',
       );
     });
@@ -155,7 +155,7 @@ describe('ReactDOMServer', () => {
     it('should throw prop mapping error for an <iframe /> with invalid props', () => {
       expect(() => {
         ReactDOMServer.renderToString(<iframe style="border:none;" />);
-      }).toThrowError(
+      }).toThrow(
         'The `style` prop expects a mapping from style properties to values, not ' +
           "a string. For example, style={{marginRight: spacing + 'em'}} when using JSX.",
       );
@@ -290,7 +290,7 @@ describe('ReactDOMServer', () => {
     it('should throw with silly args', () => {
       expect(
         ReactDOMServer.renderToStaticMarkup.bind(ReactDOMServer, {x: 123}),
-      ).toThrowError(
+      ).toThrow(
         'Objects are not valid as a React child (found: object with keys {x})',
       );
     });
@@ -715,7 +715,7 @@ describe('ReactDOMServer', () => {
             <span key={2} />
           </Wrapper>,
         );
-      }).toThrowError(/Cannot assign to read only property.*/);
+      }).toThrow(/Cannot assign to read only property.*/);
     } else {
       expect(
         ReactDOMServer.renderToStaticMarkup(
@@ -966,7 +966,7 @@ describe('ReactDOMServer', () => {
 
     expect(() => {
       ReactDOMServer.renderToString(<Foo />);
-    }).toThrow("Cannot read property 'world' of undefined");
+    }).toThrow("Cannot read properties of undefined (reading 'world')");
   });
 
   it('should warn when class contextType is undefined', () => {
@@ -981,7 +981,7 @@ describe('ReactDOMServer', () => {
 
     expect(() => {
       ReactDOMServer.renderToString(<Foo />);
-    }).toThrow("Cannot read property 'world' of undefined");
+    }).toThrow("Cannot read properties of undefined (reading 'world')");
     assertConsoleErrorDev([
       'Foo defines an invalid contextType. ' +
         'contextType should point to the Context object returned by React.createContext(). ' +
@@ -1007,7 +1007,7 @@ describe('ReactDOMServer', () => {
 
     expect(() => {
       ReactDOMServer.renderToString(<Foo />);
-    }).toThrow("Cannot read property 'hello' of undefined");
+    }).toThrow("Cannot read properties of undefined (reading 'hello')");
     assertConsoleErrorDev([
       'Foo defines an invalid contextType. ' +
         'contextType should point to the Context object returned by React.createContext(). ' +
@@ -1026,7 +1026,7 @@ describe('ReactDOMServer', () => {
 
     expect(() => {
       ReactDOMServer.renderToString(<Foo />);
-    }).toThrow("Cannot read property 'world' of undefined");
+    }).toThrow("Cannot read properties of undefined (reading 'world')");
     assertConsoleErrorDev([
       'Foo defines an invalid contextType. ' +
         'contextType should point to the Context object returned by React.createContext(). ' +
diff --git a/packages/react-reconciler/src/__tests__/ReactHooksWithNoopRenderer-test.js b/packages/react-reconciler/src/__tests__/ReactHooksWithNoopRenderer-test.js
index f48a78de4afb..425b3aade7e1 100644
--- a/packages/react-reconciler/src/__tests__/ReactHooksWithNoopRenderer-test.js
+++ b/packages/react-reconciler/src/__tests__/ReactHooksWithNoopRenderer-test.js
@@ -234,7 +234,7 @@ describe('ReactHooksWithNoopRenderer', () => {
 
   it('throws when called outside the render phase', async () => {
     expect(() => useState(0)).toThrow(
-      "Cannot read property 'useState' of null",
+      "Cannot read properties of null (reading 'useState')",
     );
     assertConsoleErrorDev([
       'Invalid hook call. Hooks can only be called inside of the body of a function component. This could happen for' +
diff --git a/scripts/jest/matchers/toThrow.js b/scripts/jest/matchers/toThrow.js
deleted file mode 100644
index 204a2fc713ca..000000000000
--- a/scripts/jest/matchers/toThrow.js
+++ /dev/null
@@ -1,50 +0,0 @@
-'use strict';
-
-// V8 uses a different message format when reading properties of null or undefined.
-// Older versions use e.g. "Cannot read property 'world' of undefined"
-// Newer versions use e.g. "Cannot read properties of undefined (reading 'world')"
-// This file overrides the built-in toThrow() matches to handle both cases,
-// enabling the React project to support Node 12-16 without forking tests.
-
-const toThrowMatchers = require('expect/build/toThrowMatchers').default;
-const builtInToThrow = toThrowMatchers.toThrow;
-
-// Detect the newer stack format:
-let newErrorFormat = false;
-try {
-  null.test();
-} catch (error) {
-  if (error.message.includes('Cannot read properties of null')) {
-    newErrorFormat = true;
-  }
-}
-
-// Detect the message pattern we need to rename:
-const regex = /Cannot read property '([^']+)' of (.+)/;
-
-// Massage strings (written in the older format) to match the newer format
-// if tests are currently running on Node 16+
-function normalizeErrorMessage(message) {
-  if (newErrorFormat) {
-    const match = message.match(regex);
-    if (match) {
-      return `Cannot read properties of ${match[2]} (reading '${match[1]}')`;
-    }
-  }
-
-  return message;
-}
-
-function toThrow(value, expectedValue) {
-  if (typeof expectedValue === 'string') {
-    expectedValue = normalizeErrorMessage(expectedValue);
-  } else if (expectedValue instanceof Error) {
-    expectedValue.message = normalizeErrorMessage(expectedValue.message);
-  }
-
-  return builtInToThrow.call(this, value, expectedValue);
-}
-
-module.exports = {
-  toThrow,
-};
diff --git a/scripts/jest/setupTests.js b/scripts/jest/setupTests.js
index 28586d94b593..48e1a51f9436 100644
--- a/scripts/jest/setupTests.js
+++ b/scripts/jest/setupTests.js
@@ -47,7 +47,6 @@ if (process.env.REACT_CLASS_EQUIVALENCE_TEST) {
 
   expect.extend({
     ...require('./matchers/reactTestMatchers'),
-    ...require('./matchers/toThrow'),
   });
 
   // We have a Babel transform that inserts guards against infinite loops.
diff --git a/scripts/jest/spec-equivalence-reporter/setupTests.js b/scripts/jest/spec-equivalence-reporter/setupTests.js
index a561fb4b4d1d..e02839788325 100644
--- a/scripts/jest/spec-equivalence-reporter/setupTests.js
+++ b/scripts/jest/spec-equivalence-reporter/setupTests.js
@@ -60,5 +60,4 @@ afterEach(assertConsoleLogsCleared);
 
 expect.extend({
   ...require('../matchers/reactTestMatchers'),
-  ...require('../matchers/toThrow'),
 });