feat(jest-snapshot): Support Error.cause in snapshots

CHANGELOG.md

@@ -7,6 +7,7 @@
 - `[jest-environment-jsdom]` [**BREAKING**] Upgrade JSDOM to v22 ([#13825](https://github.com/jestjs/jest/pull/13825))
 - `[@jest/fake-timers]` [**BREAKING**] Upgrade `@sinonjs/fake-timers` to v11 ([#14544](https://github.com/jestjs/jest/pull/14544))
 - `[@jest/schemas]` Upgrade `@sinclair/typebox` to v0.31 ([#14072](https://github.com/jestjs/jest/pull/14072))
+- `[jest-snapshot]` [**BREAKING**] Add support for [Error causes](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/cause) in snapshots ([#13965](https://github.com/facebook/jest/pull/13965))
 - `[pretty-format]` [**BREAKING**] Do not render empty string children (`''`) in React plugin ([#14470](https://github.com/facebook/jest/pull/14470))
 
 ### Fixes

e2e/__tests__/__snapshots__/toThrowErrorMatchingInlineSnapshot.test.ts.snap

@@ -18,6 +18,50 @@ exports[`updates existing snapshot: updated snapshot 1`] = `
 "
 `;
 
+exports[`works fine when function throws error with cause: initial write with cause 1`] = `
+"test('works fine when function throws error', () => {
+  function ErrorWithCause(message, cause) {
+    const err = new Error(message, {cause});
+    if (err.cause !== cause) {
+      // cause does not exist in old versions of node
+      err.cause = cause;
+    }
+    return err;
+  }
+  expect(() => {
+    throw ErrorWithCause(
+      'apple',
+      ErrorWithCause('banana', ErrorWithCause('orange')),
+    );
+  }).toThrowErrorMatchingInlineSnapshot(\`
+    "apple
+    Cause: banana
+    Cause: orange"
+  \`);
+});
+"
+`;
+
+exports[`works fine when function throws error with string cause: initial write with cause 1`] = `
+"test('works fine when function throws error', () => {
+  function ErrorWithCause(message, cause) {
+    const err = new Error(message, {cause});
+    if (err.cause !== cause) {
+      // cause does not exist in old versions of node
+      err.cause = cause;
+    }
+    return err;
+  }
+  expect(() => {
+    throw ErrorWithCause('apple', 'here is a cause');
+  }).toThrowErrorMatchingInlineSnapshot(\`
+    "apple
+    Cause: here is a cause"
+  \`);
+});
+"
+`;
+
 exports[`works fine when function throws error: initial write 1`] = `
 "test('works fine when function throws error', () => {
   expect(() => {

e2e/__tests__/toThrowErrorMatchingInlineSnapshot.test.ts

@@ -43,6 +43,69 @@ test('works fine when function throws error', () => {
   }
 });
 
+test('works fine when function throws error with cause', () => {
+  const filename = 'works-fine-when-function-throws-error-with-cause.test.js';
+  const template = makeTemplate(`
+    test('works fine when function throws error', () => {
+      function ErrorWithCause(message, cause) {
+        const err = new Error(message, {cause});
+        if (err.cause !== cause) {
+          // cause does not exist in old versions of node
+          err.cause = cause;
+        }
+        return err;
+      }
+      expect(() => {
+        throw ErrorWithCause('apple',
+          ErrorWithCause('banana',
+            ErrorWithCause('orange')
+          )
+        );
+      })
+        .toThrowErrorMatchingInlineSnapshot();
+    });
+  `);
+
+  {
+    writeFiles(TESTS_DIR, {[filename]: template()});
+    const {stderr, exitCode} = runJest(DIR, ['-w=1', '--ci=false', filename]);
+    const fileAfter = readFile(filename);
+    expect(stderr).toMatch('1 snapshot written from 1 test suite.');
+    expect(fileAfter).toMatchSnapshot('initial write with cause');
+    expect(exitCode).toBe(0);
+  }
+});
+
+test('works fine when function throws error with string cause', () => {
+  const filename =
+    'works-fine-when-function-throws-error-with-string-cause.test.js';
+  const template = makeTemplate(`
+    test('works fine when function throws error', () => {
+      function ErrorWithCause(message, cause) {
+        const err = new Error(message, {cause});
+        if (err.cause !== cause) {
+          // cause does not exist in old versions of node
+          err.cause = cause;
+        }
+        return err;
+      }
+      expect(() => {
+        throw ErrorWithCause('apple', 'here is a cause');
+      })
+        .toThrowErrorMatchingInlineSnapshot();
+    });
+  `);
+
+  {
+    writeFiles(TESTS_DIR, {[filename]: template()});
+    const {stderr, exitCode} = runJest(DIR, ['-w=1', '--ci=false', filename]);
+    const fileAfter = readFile(filename);
+    expect(stderr).toMatch('1 snapshot written from 1 test suite.');
+    expect(fileAfter).toMatchSnapshot('initial write with cause');
+    expect(exitCode).toBe(0);
+  }
+});
+
 test('updates existing snapshot', () => {
   const filename = 'updates-existing-snapshot.test.js';
   const template = makeTemplate(`

packages/jest-snapshot/src/index.ts

@@ -5,6 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+import {types} from 'util';
 import * as fs from 'graceful-fs';
 import type {Config} from '@jest/types';
 import type {MatcherFunctionWithContext} from 'expect';
@@ -518,12 +519,25 @@ const _toThrowErrorMatchingSnapshot = (
     );
   }
 
+  let message = error.message;
+  while ('cause' in error) {
+    error = error.cause;
+    if (types.isNativeError(error) || error instanceof Error) {
+      message += `\nCause: ${error.message}`;
+    } else {
+      if (typeof error === 'string') {
+        message += `\nCause: ${error}`;
+      }
+      break;
+    }
+  }
+
   return _toMatchSnapshot({
     context,
     hint,
     inlineSnapshot,
     isInline,
     matcherName,
-    received: error.message,
+    received: message,
   });
 };