• ✅ Starting dependency impact analysis... completed successfully (5 steps)

🔧 @testing-library/jest-dom: The '/extend-expect' entry point was removed in v6.0.0. The import 'import '@testing-library/jest-dom/extend-expect';' in app/javascript/mastodon/test_setup.js will fail with a module not found error. This must be changed to 'import '@testing-library/jest-dom';' to work with v6.x.

Status: 🔧 Fixed - Automatically resolved

🔧 Automated Fix Applied

Fixed via 1 ticket(s): Update @testing-library/jest-dom import path in test setup

The codebase directly imports '@testing-library/jest-dom/extend-expect' which was removed in v6.0.0. This will cause a runtime module not found error that breaks all tests.

Validations (3)

1. Found direct usage of 'import '@testing-library/jest-dom/extend-expect';' on line 1 which will fail with v6.x as this entry point was removed

2. Jest config points to setupFilesAfterEnv: ['/app/javascript/mastodon/test_setup.js'] which loads the problematic import

3. Confirmed widespread community reports that '/extend-expect' entry point was removed in v6.0.0, causing 'Cannot find module' errors across many projects

Citations (2)

mastodon/app/javascript/mastodon/test_setup.js

Line 1 in a7e5146

import '@testing-library/jest-dom/extend-expect';

This import will fail with v6.x because the '/extend-expect' entry point was removed. Fix by changing to 'import '@testing-library/jest-dom';'

Additional Citations:

Summary: Community reports confirming the removal of '/extend-expect' entry point in v6.0.0 causes module not found errors

https://stackoverflow.com/questions/77328459/cannot-find-module-testing-library-jest-dom-extend-expect-from-jest-setup-js

Cannot find module '@testing-library/jest-dom/extend-expect' from 'jest.setup.js'

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🔧 @testing-library/jest-dom: Removed the extend-expect script entry point - import '@testing-library/jest-dom/extend-expect' no longer works

Status: 🔧 Fixed - Automatically resolved

🔧 Automated Fix Applied

Fixed via 1 ticket(s): Update @testing-library/jest-dom import path in test setup

This describes the same breaking change as the first item. The codebase imports the removed '@testing-library/jest-dom/extend-expect' path.

Validations (2)

1. Found the problematic import in app/javascript/mastodon/test_setup.js line 1

2. This is a duplicate description of the same underlying issue - the removal of the extend-expect entry point

Citations (1)

mastodon/app/javascript/mastodon/test_setup.js

Line 1 in a7e5146

import '@testing-library/jest-dom/extend-expect';

This import uses the removed extend-expect entry point and will fail with v6.x

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✓ @testing-library/jest-dom: Jest setup configuration must change from setupFilesAfterEnv: ['@testing-library/jest-dom/extend-expect'] to setupFilesAfterEnv: ['@testing-library/jest-dom']

Status: ✓ Safe - No impact detected

The Jest configuration does not directly reference '@testing-library/jest-dom/extend-expect'. It uses a setup file pattern which is the recommended approach. The actual breaking change is in the setup file content, not the Jest configuration structure.

Validations (3)

1. The Jest config uses setupFilesAfterEnv: ['/app/javascript/mastodon/test_setup.js'] which points to a setup file, not directly to the library

2. The setup file app/javascript/mastodon/test_setup.js contains the problematic import that would need fixing

3. No direct usage of '@testing-library/jest-dom/extend-expect' in Jest config - the config points to a setup file instead

Citations (1)

mastodon/jest.config.js

Line 13 in a7e5146

setupFilesAfterEnv: ['<rootDir>/app/javascript/mastodon/test_setup.js'],

Jest config uses proper setup file pattern, not direct library import path, so no configuration change needed

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✓ @testing-library/jest-dom: TypeScript configuration changes required - types configuration pattern that worked in v5 may require updates in v6

Status: ✓ Safe - No impact detected

The project's TypeScript configuration does not explicitly configure @testing-library/jest-dom types, so it won't be affected by the TypeScript configuration changes in v6. The basic tsconfig.json setup should continue working.

Validations (3)

1. The tsconfig.json does not include '@testing-library/jest-dom' in the types array, only basic compiler options are set

2. No explicit types configuration for jest-dom found in tsconfig.json

3. Found community reports of TypeScript configuration problems with v6, particularly with types array configuration

Citations (2)

mastodon/tsconfig.json

Line 2 in a7e5146

"compilerOptions": {

TypeScript config uses basic setup without explicit jest-dom types configuration, so v6 TypeScript changes won't impact this project

Additional Citations:

Summary: Evidence of TypeScript configuration issues in v6, but this project doesn't use the problematic pattern

testing-library/jest-dom#559

"types": ["jest", "@testing-library/jest-dom"] not working after v6 upgrade

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✓ @testing-library/jest-dom: Some matchers have been deprecated in favor of more comprehensive alternatives (e.g., prefer toHaveAccessibleErrorMessage over deprecated alternatives)

Status: ✓ Safe - No impact detected

The codebase does not use any jest-dom custom matchers in its test files. Tests rely on standard Jest matchers like toMatchSnapshot() and toEqual(), so deprecated matcher changes won't affect this project.

Validations (3)

1. Found 10 test files but none use jest-dom custom matchers - tests use basic Jest assertions like toMatchSnapshot() and toEqual()

2. No matches found for common jest-dom matchers like toBeInTheDocument, toHaveClass, toHaveAccessibleErrorMessage, etc.

3. Confirmed that some matchers have been deprecated in favor of toHaveAccessibleErrorMessage and other comprehensive alternatives

Citations (2)

mastodon/app/javascript/mastodon/components/__tests__/button-test.jsx

Line 27 in a7e5146

expect(handler.mock.calls.length).toEqual(1);

Tests use standard Jest matchers rather than jest-dom custom matchers, so deprecated matcher changes don't impact this codebase

Additional Citations:

Summary: Documentation confirming deprecated matchers exist in v6, but this project doesn't use them

https://testing-library.com/docs/ecosystem-jest-dom/

This custom matcher is deprecated. Prefer toHaveAccessibleErrorMessage instead

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