What is Jest and what are its key features?
Jest is a JavaScript testing framework developed by Facebook that focuses on simplicity. Key features include: 1) Zero config setup for most JavaScript projects, 2) Snapshot testing, 3) Built-in code coverage reports, 4) Isolated test execution, 5) Interactive mode for test development, 6) Powerful mocking system, 7) Support for async testing.
How do you set up Jest in a project?
Jest setup involves: 1) Installing Jest using npm/yarn: 'npm install --save-dev jest', 2) Adding test script to package.json: { 'scripts': { 'test': 'jest' } }, 3) Creating test files with .test.js or .spec.js extensions, 4) Configuring Jest through jest.config.js if needed, 5) Setting up any required environment configurations.
What is the basic structure of a Jest test?
A Jest test consists of: 1) describe blocks for grouping related tests, 2) it or test blocks for individual test cases, 3) expect statements for assertions. Example:
describe('MyFunction', () => {
it('should return correct value', () => {
expect(myFunction()).toBe(true);
});
});
What are Jest matchers and how are they used?
Matchers are methods that let you test values in different ways. Common matchers include: 1) toBe() for exact equality, 2) toEqual() for deep equality, 3) toContain() for arrays/iterables, 4) toBeTruthy()/toBeFalsy() for boolean checks, 5) toMatch() for regex. Used with expect(): expect(value).matcher()
How do you handle asynchronous testing in Jest?
Async testing can be handled through: 1) Returning promises: return promise.then(), 2) Async/await: async () => { await result }, 3) Done callback: (done) => { process.then(done) }, 4) Resolves/rejects matchers: expect(promise).resolves.toBe(). Always ensure async operations complete before test ends.
What are Jest hooks and when should you use them?
Jest provides lifecycle hooks: 1) beforeAll() - runs once before all tests, 2) beforeEach() - runs before each test, 3) afterEach() - runs after each test, 4) afterAll() - runs once after all tests. Used for setup/cleanup operations. Example: setting up database connections, cleaning test data.
How does Jest handle mocking?
Jest provides multiple mocking approaches: 1) jest.fn() for function mocking, 2) jest.mock() for module mocking, 3) jest.spyOn() for monitoring function calls, 4) Manual mocks using __mocks__ directory, 5) Automatic mocking of node_modules. Mocks help isolate code for testing.
What is snapshot testing in Jest?
Snapshot testing: 1) Captures component/data structure output, 2) Saves as reference file, 3) Compares against future changes, 4) Helps detect unintended changes. Example: expect(component).toMatchSnapshot(). Useful for UI components and serializable data.
How do you handle test isolation in Jest?
Test isolation involves: 1) Using beforeEach/afterEach for setup/cleanup, 2) Avoiding shared state between tests, 3) Mocking external dependencies, 4) Using describe blocks for context separation, 5) Resetting mocks between tests using jest.clearAllMocks().
What is code coverage and how is it configured in Jest?
Code coverage measures how much code is tested. Jest configuration: 1) Add --coverage flag to test command, 2) Configure coverage settings in jest.config.js, 3) Set coverage thresholds, 4) Specify files to include/exclude, 5) Generate coverage reports in different formats.
How do you implement test suites with different configurations?
Different configurations through: 1) Multiple jest.config.js files, 2) Using --config flag, 3) Environment-specific configs, 4) Test setup files, 5) Custom test environments. Example: separating unit and integration test configs.
What are custom matchers and how do you create them?
Custom matchers: 1) Created using expect.extend(), 2) Define matcher function with pass/message, 3) Can access expect context, 4) Support async matchers, 5) Can be shared across tests. Example: expect.extend({ toBeWithinRange(received, floor, ceiling) { ... } }).
How do you handle environment variables in Jest tests?
Environment variables handled through: 1) process.env in tests, 2) .env files with jest-environment, 3) setupFiles configuration, 4) CLI arguments, 5) Custom environment setup. Consider security and isolation of test environments.
What are the best practices for organizing Jest tests?
Organization best practices: 1) Group related tests in describe blocks, 2) Use clear test descriptions, 3) Follow naming conventions (.test.js/.spec.js), 4) Organize test files alongside source code, 5) Separate unit and integration tests.
How do you handle test timeouts in Jest?
Timeout handling: 1) Global timeout in jest.config.js, 2) Individual test timeouts using jest.setTimeout(), 3) Timeout option in test blocks, 4) Async test timeout handling, 5) Custom timeout messages. Default timeout is 5 seconds.
What are Jest's CLI options and how are they used?
Common CLI options: 1) --watch for watch mode, 2) --coverage for coverage reports, 3) --verbose for detailed output, 4) --runInBand for sequential execution, 5) --testNamePattern for filtering tests. Can be configured in package.json scripts.
How do you implement test fixtures in Jest?
Test fixtures implementation: 1) Using beforeEach for setup, 2) Shared test data files, 3) Factory functions for test data, 4) Fixture cleanup in afterEach, 5) Module-level fixture definitions. Helps maintain consistent test data.
What are Jest's mock functions capabilities?
Mock functions provide: 1) Call tracking, 2) Return value specification, 3) Implementation replacement, 4) Behavior verification, 5) Async mock support. Example: const mock = jest.fn().mockReturnValue(value).
How do you handle test retries and flaky tests?
Test retry handling: 1) Configure retry attempts, 2) Implement retry logic, 3) Handle async retry scenarios, 4) Log retry attempts, 5) Analyze flaky test patterns. Use jest-retry for automated retries.
What are test contexts and how are they used?
Test contexts provide: 1) Shared state within describe blocks, 2) Setup/teardown management, 3) Data sharing between tests, 4) Context-specific configurations, 5) Isolated test environments. Used through beforeAll/beforeEach hooks.
How do you implement advanced mocking patterns?
Advanced mocking includes: 1) Partial module mocking, 2) Mock implementation factories, 3) Complex return value sequences, 4) Mock instance methods, 5) Mock timers and events. Example: jest.spyOn() with complex implementations.
What are the strategies for testing complex async flows?
Complex async testing: 1) Multiple promise chains, 2) Parallel async operations, 3) Error handling scenarios, 4) Timeout management, 5) Race condition testing. Use async/await with proper error handling.
How do you implement custom test environments?
Custom environments: 1) Extending Jest's environment, 2) Implementing global setup/teardown, 3) Custom DOM implementation, 4) Environment-specific mocks, 5) Shared environment state. Used for specialized testing needs.
What are advanced snapshot testing patterns?
Advanced snapshots: 1) Custom serializers, 2) Dynamic snapshot matching, 3) Inline snapshots, 4) Snapshot migrations, 5) Conditional snapshot updates. Used for complex component testing.
How do you implement performance testing in Jest?
Performance testing: 1) Execution time measurements, 2) Memory usage tracking, 3) Performance benchmarks, 4) Resource utilization tests, 5) Performance regression detection. Use custom metrics and assertions.
What is jest.fn() and how is it used?
jest.fn() creates a mock function that allows: 1) Tracking calls and arguments, 2) Setting return values using mockReturnValue(), 3) Implementing custom behavior using mockImplementation(), 4) Clearing/resetting mock data, 5) Verifying call conditions. Example: const mock = jest.fn().mockReturnValue('result');
How do you use jest.spyOn()?
jest.spyOn() is used to: 1) Monitor method calls on objects, 2) Preserve original implementation while tracking calls, 3) Temporarily mock method behavior, 4) Restore original implementation using mockRestore(), 5) Access call history and mock functionality. Example: jest.spyOn(object, 'method')
What is the difference between jest.fn() and jest.spyOn()?
Key differences: 1) jest.fn() creates new mock functions while spyOn monitors existing ones, 2) spyOn can restore original implementation, jest.fn() cannot, 3) spyOn requires an object and method, jest.fn() is standalone, 4) spyOn preserves original method by default, 5) jest.fn() starts as empty function.
How do you mock modules in Jest?
Module mocking uses: 1) jest.mock() for automatic mocking, 2) Manual mocks in __mocks__ directory, 3) mockImplementation() for custom behavior, 4) requireActual() for partial mocking, 5) hoisting of jest.mock() calls. Example: jest.mock('./module', () => ({ method: jest.fn() }));
What are mock return values and how are they set?
Mock return values can be set using: 1) mockReturnValue() for fixed values, 2) mockReturnValueOnce() for single calls, 3) mockImplementation() for custom logic, 4) mockResolvedValue() for promises, 5) mockRejectedValue() for promise rejections. Example: mock.mockReturnValue('result');
How do you verify mock calls?
Mock calls verified using: 1) toHaveBeenCalled() for call checking, 2) toHaveBeenCalledWith() for argument checking, 3) toHaveBeenCalledTimes() for call count, 4) mock.calls array for detailed inspection, 5) mock.results for return values. Example: expect(mock).toHaveBeenCalledWith(arg);
What is mock.mockClear() and when should it be used?
mockClear(): 1) Resets call history of mock function, 2) Used between tests to ensure isolation, 3) Doesn't reset implementation or return values, 4) Often used in beforeEach, 5) Helps prevent test interdependence. Example: beforeEach(() => { mock.mockClear(); });
How do you mock async functions?
Async mocking involves: 1) mockResolvedValue() for successful promises, 2) mockRejectedValue() for failed promises, 3) mockImplementation() with async functions, 4) Chain .then handlers for complex cases, 5) Await mock function calls in tests. Example: mock.mockResolvedValue('result');
What are manual mocks and how are they created?
Manual mocks: 1) Created in __mocks__ directory, 2) Match module name and structure, 3) Exported as module.exports, 4) Can include complex implementations, 5) Automatically used when module is required. Used for consistent mock implementations across tests.
How do you mock ES6 classes in Jest?
ES6 class mocking: 1) Use jest.mock() for class, 2) Mock constructor and methods, 3) Implement instance methods with mockImplementation, 4) Mock static methods directly, 5) Handle inheritance if needed. Example: jest.mock('./MyClass', () => { return jest.fn().mockImplementation(() => { return {method: jest.fn()}; }); });
How do you implement partial module mocking?
Partial mocking involves: 1) Using jest.mock() with partial implementations, 2) requireActual() for original methods, 3) Mixing real and mocked exports, 4) Careful management of module state, 5) Clear documentation of mixed implementation. Example: jest.mock('./module', () => ({ ...jest.requireActual('./module'), specificMethod: jest.fn() }));
What are mock implementations and how are they used?
Mock implementations: 1) Set using mockImplementation(), 2) Define custom behavior, 3) Can access call arguments, 4) Support async operations, 5) Can be changed between tests. Example: mock.mockImplementation((arg) => arg * 2);
How do you mock timers in Jest?
Timer mocking uses: 1) jest.useFakeTimers(), 2) jest.advanceTimersByTime(), 3) jest.runAllTimers(), 4) jest.runOnlyPendingTimers(), 5) jest.clearAllTimers(). Helps test setTimeout, setInterval, etc. Example: jest.useFakeTimers(); jest.advanceTimersByTime(1000);
What are the strategies for mocking HTTP requests?
HTTP request mocking: 1) Mock fetch/axios globally, 2) Use jest.mock() for HTTP clients, 3) Implement custom response handling, 4) Mock different response scenarios, 5) Handle async behavior properly. Consider using libraries like jest-fetch-mock.
How do you handle complex mock return sequences?
Complex sequences using: 1) mockReturnValueOnce() chain, 2) mockImplementation with state, 3) Array of return values, 4) Conditional return logic, 5) Mock result queues. Example: mock.mockReturnValueOnce(1).mockReturnValueOnce(2).mockReturnValue(3);
What are mocked modules limitations?
Limitations include: 1) Hoisting requirements, 2) ES6 module constraints, 3) Dynamic import challenges, 4) Circular dependency issues, 5) Reset complexities. Understanding helps avoid common pitfalls and design better tests.
How do you mock native JavaScript objects?
Native object mocking: 1) Use jest.spyOn on prototype, 2) Mock specific methods, 3) Restore original behavior, 4) Handle inheritance chain, 5) Consider side effects. Example: jest.spyOn(console, 'log').mockImplementation();
What are mock contexts and how are they used?
Mock contexts provide: 1) Custom this binding, 2) Shared state between calls, 3) Instance method simulation, 4) Constructor behavior, 5) Method chaining support. Used for complex object mocking scenarios.
How do you handle mock cleanup and restoration?
Mock cleanup involves: 1) Using mockReset(), 2) mockRestore() for spies, 3) Cleanup in afterEach, 4) Handling partial restorations, 5) Managing global mocks. Ensures test isolation and prevents side effects.
What are mock factories and how are they implemented?
Mock factories: 1) Create reusable mock configurations, 2) Generate consistent test doubles, 3) Support parameterization, 4) Enable mock composition, 5) Facilitate maintenance. Example: const createMock = (config) => jest.fn().mockImplementation(config);
How do you implement advanced module mocking patterns?
Advanced patterns include: 1) Dynamic mock generation, 2) Mock inheritance chains, 3) Conditional mock behavior, 4) Mock composition, 5) State-dependent mocking. Used for complex module interactions.
What are strategies for mocking complex async patterns?
Complex async mocking: 1) Chain multiple async operations, 2) Handle race conditions, 3) Mock streaming interfaces, 4) Simulate timeouts, 5) Test error scenarios. Example: mock.mockImplementation(async () => { /* complex async logic */ });
How do you implement stateful mocks?
Stateful mocks require: 1) Internal state management, 2) State-dependent behavior, 3) State reset mechanisms, 4) State verification, 5) Thread-safe state handling. Used for complex behavioral simulation.
What are mock orchestration patterns?
Orchestration patterns: 1) Coordinate multiple mocks, 2) Manage mock interactions, 3) Synchronize mock behavior, 4) Handle mock dependencies, 5) Implement mock workflows. Used for system-level testing.
What is the expect function in Jest and how is it used?
expect is Jest's assertion function that: 1) Takes a value to test, 2) Returns an expectation object, 3) Chains with matchers (toBe, toEqual, etc.), 4) Supports async assertions, 5) Can be extended with custom matchers. Example: expect(value).toBe(expected);
What is the difference between toBe() and toEqual()?
Key differences: 1) toBe() uses Object.is for strict equality, 2) toEqual() performs deep equality comparison, 3) toBe() is for primitives and object references, 4) toEqual() is for object/array content comparison, 5) toEqual() recursively checks nested structures.
What are the common matchers for truthiness testing?
Truthiness matchers include: 1) toBeTruthy() - checks if value is truthy, 2) toBeFalsy() - checks if value is falsy, 3) toBeNull() - checks for null, 4) toBeUndefined() - checks for undefined, 5) toBeDefined() - checks if value is not undefined.
How do you test for numeric comparisons?
Numeric matchers include: 1) toBeGreaterThan(), 2) toBeLessThan(), 3) toBeGreaterThanOrEqual(), 4) toBeLessThanOrEqual(), 5) toBeCloseTo() for floating point. Example: expect(value).toBeGreaterThan(3);
What matchers are available for string testing?
String matchers include: 1) toMatch() for regex patterns, 2) toContain() for substring checks, 3) toHaveLength() for string length, 4) toEqual() for exact matches, 5) toString() for string conversion checks. Example: expect(string).toMatch(/pattern/);
How do you test arrays and iterables?
Array matchers include: 1) toContain() for item presence, 2) toHaveLength() for array length, 3) toEqual() for deep equality, 4) arrayContaining() for partial matches, 5) toContainEqual() for object matching in arrays.
What matchers are used for object testing?
Object matchers include: 1) toEqual() for deep equality, 2) toMatchObject() for partial matching, 3) toHaveProperty() for property checks, 4) objectContaining() for subset matching, 5) toBeInstanceOf() for type checking.
How do you test for exceptions and errors?
Exception testing uses: 1) toThrow() for any error, 2) toThrowError() with specific error, 3) expect(() => {}).toThrow() syntax, 4) Error message matching, 5) Error type checking. Example: expect(() => fn()).toThrow('error message');
What is the not modifier and how is it used?
The not modifier: 1) Inverts matcher expectation, 2) Used as .not before matchers, 3) Works with all matchers, 4) Maintains proper error messages, 5) Useful for negative assertions. Example: expect(value).not.toBe(3);
How do you test promise resolutions?
Promise testing uses: 1) resolves matcher for success, 2) rejects matcher for failures, 3) Async/await syntax, 4) Return promises in tests, 5) Chain additional matchers. Example: expect(promise).resolves.toBe(value);
How do you create custom matchers?
Custom matchers created using: 1) expect.extend(), 2) Matcher function with pass/message, 3) this.isNot for negation, 4) Async matcher support, 5) Custom error messages. Example: expect.extend({ customMatcher(received, expected) { return { pass: condition, message: () => message }; } });
What are asymmetric matchers?
Asymmetric matchers: 1) Allow partial matching, 2) Include expect.any(), expect.arrayContaining(), 3) Used in object/array comparisons, 4) Support custom implementations, 5) Useful for flexible assertions. Example: expect({ prop: 'value' }).toEqual(expect.objectContaining({ prop: expect.any(String) }));
How do you test snapshot matches?
Snapshot testing uses: 1) toMatchSnapshot() matcher, 2) toMatchInlineSnapshot(), 3) Serializer customization, 4) Dynamic snapshot content, 5) Snapshot update flow. Example: expect(component).toMatchSnapshot();
What are the best practices for assertion messages?
Message best practices: 1) Clear failure descriptions, 2) Context-specific details, 3) Expected vs actual values, 4) Custom matcher messages, 5) Error hint inclusion. Helps with test debugging and maintenance.
How do you handle DOM-specific assertions?
DOM assertions use: 1) toBeInTheDocument(), 2) toHaveTextContent(), 3) toHaveAttribute(), 4) toBeVisible(), 5) toBeDisabled(). Often used with @testing-library/jest-dom matchers.
What are the strategies for testing partial matches?
Partial matching uses: 1) objectContaining(), 2) arrayContaining(), 3) stringContaining(), 4) stringMatching(), 5) Custom matchers for specific cases. Example: expect(object).toEqual(expect.objectContaining({ key: value }));
How do you handle complex object comparisons?
Complex comparisons use: 1) Deep equality checks, 2) Custom matchers, 3) Partial matching, 4) Property path assertions, 5) Nested object validation. Consider performance and maintainability.
What are assertion timeouts and how are they handled?
Timeout handling includes: 1) Setting timeout duration, 2) Async assertion timing, 3) Custom timeout messages, 4) Retry mechanisms, 5) Polling assertions. Important for async testing scenarios.
How do you test for function calls and arguments?
Function call testing uses: 1) toHaveBeenCalled(), 2) toHaveBeenCalledWith(), 3) toHaveBeenCalledTimes(), 4) toHaveBeenLastCalledWith(), 5) Call argument inspection. Used with mock functions and spies.
What are compound assertions and how are they used?
Compound assertions: 1) Chain multiple expectations, 2) Combine matchers logically, 3) Use and/or operators, 4) Group related assertions, 5) Complex condition testing. Example: expect(value).toBeDefined().and.toBeTruthy();
How do you implement advanced custom matchers?
Advanced matchers include: 1) Complex matching logic, 2) Custom error formatting, 3) Assertion composition, 4) Async matcher support, 5) Context-aware matching. Used for specialized testing needs.
What are the strategies for testing complex async patterns?
Complex async testing: 1) Multiple promise chains, 2) Race condition testing, 3) Timeout handling, 4) Error case coverage, 5) State verification. Requires careful timing management.
How do you implement state-based assertions?
State assertions include: 1) Complex state verification, 2) State transition testing, 3) Conditional assertions, 4) State history validation, 5) Side effect checking. Used for stateful component testing.
What are advanced snapshot patterns?
Advanced snapshots: 1) Dynamic content handling, 2) Serializer customization, 3) Snapshot transformations, 4) Conditional snapshots, 5) Snapshot maintenance strategies. Used for complex component testing.
How do you implement performance assertions?
Performance assertions: 1) Execution time checks, 2) Resource usage validation, 3) Performance threshold testing, 4) Benchmark comparisons, 5) Performance regression detection. Used for performance testing.
What are the patterns for testing complex data structures?
Complex data testing: 1) Graph structure validation, 2) Tree traversal assertions, 3) Collection relationship testing, 4) Data integrity checks, 5) Structure transformation verification. Used for complex data scenarios.
How do you initialize Jest in a new project?
Jest initialization involves: 1) Installing Jest: npm install --save-dev jest, 2) Adding test script to package.json: { 'scripts': { 'test': 'jest' } }, 3) Creating jest.config.js (optional), 4) Setting up test directories, 5) Configuring environment if needed.
What is jest.config.js and what are its key options?
jest.config.js is the main configuration file that includes: 1) testEnvironment setting, 2) moduleFileExtensions, 3) setupFilesAfterEnv for setup files, 4) testMatch for test file patterns, 5) coverageThreshold settings, 6) transform configurations for preprocessors.
How do you configure test environments in Jest?
Test environment configuration includes: 1) Setting testEnvironment in config (jsdom/node), 2) Creating custom environments, 3) Configuring environment variables, 4) Setting up global mocks, 5) Handling environment-specific setup.
What are transform configurations in Jest?
Transform configs handle: 1) File preprocessing before tests, 2) Babel integration for modern JavaScript, 3) TypeScript transformation, 4) Custom transformers for specific files, 5) Cache configuration for transforms.
How do you configure test file patterns?
Test pattern configuration uses: 1) testMatch for glob patterns, 2) testRegex for regex patterns, 3) testPathIgnorePatterns for exclusions, 4) File naming conventions (.test.js, .spec.js), 5) Directory organization patterns.
What is setupFilesAfterEnv and how is it used?
setupFilesAfterEnv: 1) Runs setup code after test framework initialization, 2) Configures global test setup, 3) Adds custom matchers, 4) Sets up test environment, 5) Configures global mocks. Example: ['./jest.setup.js']
How do you configure code coverage in Jest?
Coverage configuration includes: 1) collectCoverage flag, 2) coverageDirectory setting, 3) coverageThreshold requirements, 4) collectCoverageFrom patterns, 5) coverageReporters options for report formats.
What are module name mappings and how are they configured?
Module mappings use: 1) moduleNameMapper in config, 2) Alias definitions, 3) Regular expression patterns, 4) Identity-obj-proxy for style imports, 5) Custom module resolvers. Helps with import resolution and mocking.
How do you configure test timeouts?
Timeout configuration includes: 1) Global testTimeout setting, 2) Individual test timeouts, 3) Async operation timeouts, 4) Setup/teardown timeouts, 5) Custom timeout messages. Default is usually 5000ms.
What are globals in Jest configuration?
Globals configuration: 1) Define global variables, 2) Set up global mocks, 3) Configure global setup/teardown, 4) Define global matchers, 5) Set up global test utilities. Available throughout test suite.
How do you configure Jest for TypeScript?
TypeScript configuration includes: 1) Installing ts-jest, 2) Configuring transform with ts-jest, 3) Setting up tsconfig.json, 4) Configuring type checking, 5) Handling TypeScript paths and aliases.
What are the strategies for configuring test environments for different platforms?
Platform configuration involves: 1) Environment-specific configs, 2) Conditional setup logic, 3) Platform-specific mocks, 4) Environment detection, 5) Platform-specific test runners.
How do you configure custom reporters?
Reporter configuration includes: 1) Custom reporter implementation, 2) Reporter options setup, 3) Multiple reporter configuration, 4) Output formatting, 5) Integration with CI/CD systems.
What are the approaches for configuring test data management?
Test data configuration: 1) Fixture setup locations, 2) Data loading strategies, 3) Cleanup mechanisms, 4) Data isolation approaches, 5) Shared test data management.
How do you configure snapshot testing?
Snapshot configuration: 1) snapshotSerializers setup, 2) Snapshot directory location, 3) Update and retention policies, 4) Custom serializers, 5) Snapshot format options.
What are strategies for configuring test parallelization?
Parallelization config includes: 1) maxWorkers setting, 2) Worker pool configuration, 3) Test file distribution, 4) Resource allocation, 5) Parallel run coordination.
How do you configure custom matchers?
Custom matcher configuration: 1) Matcher implementation, 2) Global matcher registration, 3) TypeScript definitions, 4) Matcher error messages, 5) Matcher documentation.
What are the approaches for configuring test filtering?
Test filtering config: 1) testNamePattern settings, 2) Test file patterns, 3) Tag-based filtering, 4) Run group configuration, 5) Conditional test execution.
How do you configure test retry behavior?
Retry configuration: 1) jest-retry setup, 2) Retry attempts settings, 3) Retry delay configuration, 4) Failure conditions, 5) Retry reporting options.
What are patterns for configuring test isolation?
Isolation configuration: 1) Test environment isolation, 2) State reset mechanisms, 3) Module isolation, 4) Database isolation, 5) Resource cleanup strategies.
How do you implement advanced test environment configurations?
Advanced environment config: 1) Custom environment implementation, 2) Environment chains, 3) Dynamic environment setup, 4) Environment state management, 5) Environment cleanup strategies.
What are strategies for configuring complex test suites?
Complex suite configuration: 1) Multi-project setup, 2) Shared configurations, 3) Dynamic config generation, 4) Configuration inheritance, 5) Project-specific overrides.
How do you implement custom test runners?
Custom runner implementation: 1) Runner API implementation, 2) Test execution flow, 3) Result reporting, 4) Resource management, 5) Integration with Jest infrastructure.
What are approaches for configuring test monitoring?
Monitoring configuration: 1) Metric collection setup, 2) Performance monitoring, 3) Resource tracking, 4) Alert configuration, 5) Monitoring integration points.
How do you configure advanced code coverage analysis?
Advanced coverage config: 1) Custom coverage reporters, 2) Coverage analysis tools, 3) Branch coverage requirements, 4) Coverage enforcement rules, 5) Coverage trend analysis.
What are patterns for configuring test data factories?
Factory configuration: 1) Factory implementation patterns, 2) Data generation strategies, 3) Factory composition, 4) State management, 5) Factory cleanup mechanisms.
How do you implement custom test schedulers?
Scheduler implementation: 1) Test execution ordering, 2) Resource allocation, 3) Priority management, 4) Dependency resolution, 5) Schedule optimization.
What are strategies for configuring test infrastructure?
Infrastructure configuration: 1) CI/CD integration, 2) Resource provisioning, 3) Environment management, 4) Scaling strategies, 5) Infrastructure monitoring.
How do you configure advanced mocking systems?
Advanced mocking config: 1) Custom mock factories, 2) Mock state management, 3) Mock verification systems, 4) Mock cleanup strategies, 5) Mock interaction recording.
What is React Testing Library and how does it work with Jest?
React Testing Library: 1) Works with Jest as test runner, 2) Provides utilities for testing React components, 3) Focuses on testing behavior over implementation, 4) Encourages accessibility-first testing, 5) Uses queries to find elements. Example: render(<Component />); expect(screen.getByText('text')).toBeInTheDocument();
How do you test component rendering?
Component rendering tests: 1) Use render function from Testing Library, 2) Query rendered elements, 3) Assert on element presence, 4) Check component content, 5) Verify proper props rendering. Example: const { getByText } = render(<Component prop={value} />);
What are the different types of queries in React Testing Library?
Query types include: 1) getBy* for elements that should be present, 2) queryBy* for elements that might not exist, 3) findBy* for async elements, 4) getAllBy*, queryAllBy*, findAllBy* for multiple elements, 5) Role-based, text-based, and label-based queries.
How do you test user events in React components?
User event testing: 1) Import userEvent from @testing-library/user-event, 2) Simulate user interactions, 3) Assert on resulting changes, 4) Handle async events, 5) Test form interactions. Example: await userEvent.click(button); expect(result).toBeVisible();
What is the role of jest-dom and its custom matchers?
jest-dom provides: 1) DOM-specific matchers, 2) toBeInTheDocument(), 3) toHaveClass(), 4) toBeVisible(), 5) toHaveValue() and other UI-specific assertions. Enhances Jest for DOM testing.
How do you test component props?
Props testing includes: 1) Rendering with different prop values, 2) Testing prop type validation, 3) Verifying prop updates, 4) Testing default props, 5) Testing required props. Example: render(<Component testProp='value' />);
What is the proper way to test forms in React?
Form testing involves: 1) Input change simulation, 2) Form submission testing, 3) Validation testing, 4) Error message verification, 5) Form state testing. Use userEvent for input interactions.
How do you test React hooks?
Hook testing requires: 1) @testing-library/react-hooks, 2) renderHook utility, 3) Testing state updates, 4) Testing hook effects, 5) Testing custom hook logic. Example: const { result } = renderHook(() => useCustomHook());
What is the importance of accessibility testing in React?
Accessibility testing includes: 1) Role-based queries, 2) ARIA attribute testing, 3) Keyboard navigation testing, 4) Screen reader compatibility, 5) Color contrast verification. Ensures inclusive user experience.
How do you test component state changes?
State testing involves: 1) Triggering state updates, 2) Verifying state changes, 3) Testing state-dependent rendering, 4) Testing state transitions, 5) Async state updates. Focus on behavior over implementation.
How do you test async component behavior?
Async testing includes: 1) Using findBy* queries, 2) Waiting for element changes, 3) Testing loading states, 4) Error state testing, 5) Data fetching verification. Example: await findByText('loaded content');
What are strategies for testing context providers?
Context testing involves: 1) Wrapping components in providers, 2) Testing context updates, 3) Testing consumer behavior, 4) Multiple context interaction, 5) Context state changes.
How do you test component integration with Redux?
Redux integration testing: 1) Providing store wrapper, 2) Testing connected components, 3) Dispatching actions, 4) Testing state updates, 5) Testing selectors. Use proper store setup.
What are approaches for testing routing in React?
Router testing includes: 1) MemoryRouter setup, 2) Route rendering verification, 3) Navigation testing, 4) Route parameter testing, 5) Route protection testing. Consider router context.
How do you test custom hooks with dependencies?
Dependencies testing: 1) Mocking external hooks, 2) Testing dependency interactions, 3) Testing error cases, 4) Testing cleanup, 5) Testing hook composition. Use proper isolation.
What are patterns for testing error boundaries?
Error boundary testing: 1) Error simulation, 2) Fallback rendering, 3) Error recovery, 4) Props passing through boundaries, 5) Nested error boundaries. Test error handling.
How do you test component performance?
Performance testing: 1) Render timing measurement, 2) Re-render optimization verification, 3) Memory leak detection, 4) React profiler integration, 5) Performance regression testing.
What are strategies for testing component composition?
Composition testing: 1) Testing component hierarchies, 2) Props drilling verification, 3) Component interaction testing, 4) Render prop testing, 5) HOC testing. Test component relationships.
How do you test component side effects?
Side effect testing: 1) useEffect testing, 2) Cleanup verification, 3) External interaction testing, 4) Timing dependencies, 5) Side effect ordering. Consider effect dependencies.
What are patterns for testing component lifecycles?
Lifecycle testing: 1) Mount behavior testing, 2) Update verification, 3) Unmount cleanup testing, 4) State persistence, 5) Effect timing. Test component phases.
How do you implement advanced component testing patterns?
Advanced patterns: 1) Component test factories, 2) Reusable test utilities, 3) Custom render methods, 4) Test composition, 5) Shared test behaviors. Improve test maintainability.
What are strategies for testing complex UI interactions?
Complex UI testing: 1) Multi-step interaction flows, 2) Conditional rendering paths, 3) State machine testing, 4) Animation testing, 5) Gesture handling. Test user scenarios.
How do you test component integration with microservices?
Microservice integration: 1) Service communication testing, 2) API interaction verification, 3) Error handling, 4) State synchronization, 5) Service dependency management.
What are approaches for testing component scaling?
Scaling testing: 1) Large data set handling, 2) Performance with many components, 3) Memory optimization, 4) Render optimization, 5) Resource management. Test scalability limits.
How do you implement visual regression testing?
Visual testing: 1) Screenshot comparison, 2) Layout verification, 3) Style regression testing, 4) Component visual states, 5) Responsive design testing. Use visual testing tools.
What are patterns for testing component security?
Security testing: 1) XSS prevention, 2) Data sanitization, 3) Authentication flows, 4) Authorization checks, 5) Secure props handling. Test security measures.
How do you test advanced state management patterns?
Advanced state testing: 1) Complex state machines, 2) State orchestration, 3) State synchronization, 4) Persistence testing, 5) State recovery scenarios. Test state complexity.
What are strategies for testing component monitoring?
Monitoring testing: 1) Performance metrics, 2) Error tracking, 3) Usage analytics, 4) Resource monitoring, 5) Health checks. Test monitoring integration.
How do you implement component stress testing?
Stress testing: 1) Load testing components, 2) Resource limits testing, 3) Concurrent operation handling, 4) Error recovery under stress, 5) Performance degradation testing.
What is integration testing and how does it differ from unit testing?
Integration testing: 1) Tests interactions between components/modules, 2) Verifies combined functionality, 3) Tests real dependencies (vs mocked in unit tests), 4) Focuses on component communication, 5) Tests larger parts of the application together. More comprehensive but slower than unit tests.
How do you set up integration tests in Jest?
Setup includes: 1) Configuring test environment, 2) Setting up test databases/services, 3) Creating test fixtures, 4) Configuring global setup/teardown, 5) Setting appropriate timeouts. Example: setupFilesAfterEnv for global setup.
What are common integration test patterns?
Common patterns: 1) Component interaction testing, 2) API integration testing, 3) Database integration testing, 4) Service integration testing, 5) End-to-end flows. Focus on testing interfaces between parts.
How do you handle test data in integration tests?
Test data handling: 1) Setup test databases, 2) Create seed data, 3) Manage test data isolation, 4) Clean up after tests, 5) Use realistic test data. Important for meaningful integration tests.
What is the role of mocking in integration tests?
Mocking in integration tests: 1) Mock external services selectively, 2) Keep core integrations real, 3) Mock non-essential dependencies, 4) Use realistic mock data, 5) Balance between isolation and realism.
How do you test API integrations?
API integration testing: 1) Test real API endpoints, 2) Verify request/response handling, 3) Test error scenarios, 4) Check authentication/authorization, 5) Test API versioning. Use actual HTTP calls.
What are best practices for database integration testing?
Database testing practices: 1) Use test database instance, 2) Reset database state between tests, 3) Test transactions and rollbacks, 4) Verify data integrity, 5) Test database migrations.
How do you handle test isolation in integration tests?
Test isolation involves: 1) Independent test databases, 2) Cleaning up test data, 3) Resetting state between tests, 4) Isolating external services, 5) Managing shared resources. Prevents test interference.
What are strategies for testing service interactions?
Service testing strategies: 1) Test service communication, 2) Verify service contracts, 3) Test service dependencies, 4) Check error handling, 5) Test service state management.
How do you handle asynchronous operations in integration tests?
Async handling: 1) Use async/await syntax, 2) Set appropriate timeouts, 3) Handle promise chains, 4) Test concurrent operations, 5) Verify async state changes. Important for realistic testing.
How do you test component communication patterns?
Component communication testing: 1) Test props passing, 2) Verify event handling, 3) Test context updates, 4) Check state propagation, 5) Test component lifecycles. Focus on interaction points.
What are approaches for testing microservice interactions?
Microservice testing: 1) Test service discovery, 2) Verify service communication, 3) Test failure scenarios, 4) Check service dependencies, 5) Test service scaling. Consider distributed nature.
How do you test data flow between components?
Data flow testing: 1) Verify data passing, 2) Test state updates, 3) Check data transformations, 4) Test data validation, 5) Verify data consistency. Focus on data integrity.
What are strategies for testing external service integrations?
External service testing: 1) Test API contracts, 2) Handle authentication, 3) Test error scenarios, 4) Verify data formats, 5) Test service availability. Consider service stability.
How do you test error handling across components?
Error handling testing: 1) Test error propagation, 2) Verify error recovery, 3) Test error boundaries, 4) Check error logging, 5) Test error state management. Important for reliability.
What are approaches for testing authentication flows?
Authentication testing: 1) Test login flows, 2) Verify token handling, 3) Test permission checks, 4) Check session management, 5) Test authentication errors. Critical for security.
How do you test state management integrations?
State management testing: 1) Test store interactions, 2) Verify state updates, 3) Test state synchronization, 4) Check state persistence, 5) Test state cleanup. Focus on data flow.
What are patterns for testing cache integrations?
Cache testing: 1) Test cache operations, 2) Verify cache invalidation, 3) Test cache consistency, 4) Check cache performance, 5) Test cache failures. Important for performance.
How do you test message queue integrations?
Queue testing: 1) Test message publishing, 2) Verify message consumption, 3) Test queue operations, 4) Check message ordering, 5) Test queue errors. Focus on reliability.
What are strategies for testing file system operations?
File system testing: 1) Test file operations, 2) Verify file permissions, 3) Test file streams, 4) Check file cleanup, 5) Test file locks. Consider system interactions.
How do you implement complex integration scenarios?
Complex integration: 1) Test multi-step flows, 2) Verify system interactions, 3) Test state transitions, 4) Check data consistency, 5) Test recovery scenarios. Focus on system behavior.
What are approaches for testing distributed systems?
Distributed testing: 1) Test network partitions, 2) Verify consensus protocols, 3) Test leader election, 4) Check data replication, 5) Test system recovery. Consider CAP theorem.
How do you test real-time system integrations?
Real-time testing: 1) Test WebSocket connections, 2) Verify event streaming, 3) Test pub/sub patterns, 4) Check message ordering, 5) Test connection recovery. Focus on timing.
What are strategies for testing system scalability?
Scalability testing: 1) Test load distribution, 2) Verify system capacity, 3) Test resource scaling, 4) Check performance degradation, 5) Test bottlenecks. Important for growth.
How do you test data consistency in distributed systems?
Consistency testing: 1) Test eventual consistency, 2) Verify data synchronization, 3) Test conflict resolution, 4) Check consistency models, 5) Test partition tolerance. Critical for reliability.
What are patterns for testing system resilience?
Resilience testing: 1) Test failure scenarios, 2) Verify system recovery, 3) Test circuit breakers, 4) Check fallback mechanisms, 5) Test degraded operations. Focus on reliability.
How do you test system monitoring integrations?
Monitoring testing: 1) Test metric collection, 2) Verify alerting systems, 3) Test logging integration, 4) Check monitoring accuracy, 5) Test monitoring scalability. Important for operations.
What are approaches for testing system security?
Security testing: 1) Test security protocols, 2) Verify access controls, 3) Test encryption, 4) Check security boundaries, 5) Test security monitoring. Critical for protection.
How do you test system compliance requirements?
Compliance testing: 1) Test regulatory requirements, 2) Verify audit trails, 3) Test data protection, 4) Check policy enforcement, 5) Test compliance reporting. Important for regulations.
How do you measure test execution time in Jest?
Measuring execution time: 1) Use jest.useFakeTimers(), 2) Use console.time/timeEnd, 3) Implement custom timing decorators, 4) Use performance.now(), 5) Configure Jest's verbose timing option. Example: const start = performance.now(); /* test */ const duration = performance.now() - start;
What is Jest's test timeout and how does it relate to performance?
Test timeout configuration: 1) Set global timeout in config, 2) Set individual test timeouts, 3) Balance timeout vs expected performance, 4) Handle slow tests appropriately, 5) Monitor timeout failures for performance issues.
How can you identify slow tests in Jest?
Identifying slow tests: 1) Use --verbose flag, 2) Implement custom timing reporters, 3) Monitor test execution times, 4) Set timing thresholds, 5) Use test profiling tools. Helps optimize test suite performance.
What are the basic performance metrics to track in Jest tests?
Basic metrics include: 1) Test execution time, 2) Setup/teardown time, 3) Memory usage, 4) Number of assertions, 5) Test suite duration. Important for establishing baselines.
How do you handle performance testing of async operations?
Async performance testing: 1) Measure async operation duration, 2) Track concurrent operations, 3) Monitor resource usage, 4) Test throughput capabilities, 5) Handle timeouts appropriately.
What is the impact of test parallelization on performance?
Parallelization impacts: 1) Reduced total execution time, 2) Increased resource usage, 3) Potential test interference, 4) Worker process management, 5) Load balancing considerations.
How do you measure memory usage in Jest tests?
Memory measurement: 1) Use process.memoryUsage(), 2) Track heap snapshots, 3) Monitor garbage collection, 4) Measure memory leaks, 5) Implement memory thresholds.
What are common performance bottlenecks in Jest tests?
Common bottlenecks: 1) Large test setups, 2) Excessive mocking, 3) Unnecessary test repetition, 4) Poor test isolation, 5) Inefficient assertions. Identify and optimize these areas.
How do you optimize test setup and teardown?
Optimization strategies: 1) Use beforeAll when possible, 2) Minimize per-test setup, 3) Implement efficient cleanup, 4) Share setup where appropriate, 5) Cache test resources.
What role does caching play in test performance?
Caching impacts: 1) Test result caching, 2) Module caching, 3) Transform caching, 4) Resource caching, 5) Cache invalidation strategies. Proper caching improves performance.
How do you implement performance benchmarks?
Benchmark implementation: 1) Define performance baselines, 2) Create benchmark suites, 3) Measure key metrics, 4) Compare against standards, 5) Track performance trends.
What are strategies for testing component rendering performance?
Rendering performance: 1) Measure render times, 2) Track re-renders, 3) Monitor DOM updates, 4) Test large datasets, 5) Profile component lifecycle.
How do you test resource-intensive operations?
Resource testing: 1) Monitor CPU usage, 2) Track memory consumption, 3) Measure I/O operations, 4) Test concurrent processing, 5) Implement resource limits.
What are approaches for testing network performance?
Network testing: 1) Measure request latency, 2) Test concurrent requests, 3) Simulate network conditions, 4) Monitor bandwidth usage, 5) Test connection pooling.
How do you profile Jest test execution?
Test profiling: 1) Use Node.js profiler, 2) Implement custom profilers, 3) Track execution paths, 4) Measure function calls, 5) Analyze bottlenecks.
What are patterns for testing data processing performance?
Data processing: 1) Test large datasets, 2) Measure processing speed, 3) Monitor memory usage, 4) Test batch processing, 5) Benchmark algorithms.
How do you test memory leaks?
Memory leak testing: 1) Track object retention, 2) Monitor heap growth, 3) Test long-running operations, 4) Implement cleanup verification, 5) Use memory profiling tools.
What are strategies for testing cache performance?
Cache performance: 1) Measure hit rates, 2) Test cache efficiency, 3) Monitor cache size, 4) Test eviction policies, 5) Benchmark cache operations.
How do you test database performance?
Database testing: 1) Measure query performance, 2) Test connection pooling, 3) Monitor transaction speed, 4) Test concurrent access, 5) Benchmark CRUD operations.
What are approaches for testing file I/O performance?
I/O performance: 1) Measure read/write speeds, 2) Test concurrent operations, 3) Monitor file system usage, 4) Test streaming performance, 5) Benchmark file operations.
How do you implement advanced performance monitoring?
Advanced monitoring: 1) Custom metric collection, 2) Performance dashboards, 3) Trend analysis, 4) Alert systems, 5) Performance regression detection.
What are strategies for testing distributed system performance?
Distributed testing: 1) Test network latency, 2) Measure data consistency, 3) Monitor system throughput, 4) Test scalability, 5) Benchmark distributed operations.
How do you test real-time system performance?
Real-time testing: 1) Measure response times, 2) Test event processing, 3) Monitor message latency, 4) Test concurrent users, 5) Benchmark real-time operations.
What are patterns for testing microservice performance?
Microservice testing: 1) Test service communication, 2) Measure service latency, 3) Monitor resource usage, 4) Test service scaling, 5) Benchmark service operations.
How do you test system scalability?
Scalability testing: 1) Measure load handling, 2) Test resource scaling, 3) Monitor performance degradation, 4) Test concurrent operations, 5) Benchmark scaling operations.
What are approaches for testing system resilience?
Resilience testing: 1) Test failure recovery, 2) Measure degraded performance, 3) Test circuit breakers, 4) Monitor system stability, 5) Benchmark recovery operations.
How do you implement performance regression testing?
Regression testing: 1) Track performance metrics, 2) Compare against baselines, 3) Detect performance degradation, 4) Monitor trends, 5) Implement automated checks.
What are strategies for testing system optimization?
Optimization testing: 1) Identify bottlenecks, 2) Measure improvement impact, 3) Test optimization strategies, 4) Monitor resource efficiency, 5) Benchmark optimizations.
How do you test performance under load?
Load testing: 1) Simulate user load, 2) Measure system response, 3) Monitor resource usage, 4) Test concurrent users, 5) Benchmark load handling.
What are patterns for testing system capacity?
Capacity testing: 1) Measure maximum load, 2) Test resource limits, 3) Monitor system boundaries, 4) Test scaling limits, 5) Benchmark capacity handling.
What are the key principles of writing good Jest tests?
Key principles include: 1) Test isolation - each test should be independent, 2) Clear test descriptions, 3) Single assertion per test when possible, 4) Proper setup and cleanup, 5) Following the Arrange-Act-Assert pattern, 6) Testing behavior not implementation, 7) Maintaining test readability.
What is the AAA (Arrange-Act-Assert) pattern and why is it important?
AAA pattern involves: 1) Arrange - setup test data and conditions, 2) Act - perform the action being tested, 3) Assert - verify the expected outcome. Important for: test clarity, maintainability, and proper organization of test logic.
How should test files be organized?
Test organization best practices: 1) Keep tests close to source files, 2) Use consistent naming conventions (.test.js, .spec.js), 3) Group related tests in describe blocks, 4) Organize by feature or component, 5) Maintain clear file structure.
What makes a good test description?
Good test descriptions: 1) Clearly state what's being tested, 2) Describe expected behavior, 3) Use consistent terminology, 4) Follow 'it should...' pattern, 5) Are specific and unambiguous. Helps with test documentation and maintenance.
How should test data be managed?
Test data management: 1) Use fixtures for consistent data, 2) Implement factory functions, 3) Clean up test data after use, 4) Keep test data minimal and focused, 5) Avoid sharing mutable test data between tests.
What are the best practices for using mocks?
Mock best practices: 1) Only mock what's necessary, 2) Keep mocks simple, 3) Clean up mocks after tests, 4) Use meaningful mock implementations, 5) Avoid mocking everything. Mocks should be minimal and focused.
How should assertions be structured?
Assertion best practices: 1) Use specific assertions, 2) Keep assertions focused, 3) Use meaningful error messages, 4) Avoid multiple assertions when possible, 5) Test one concept per test case.
What are the guidelines for test hooks usage?
Hook guidelines: 1) Use beforeAll for one-time setup, 2) Use beforeEach for per-test setup, 3) Clean up resources in afterEach/afterAll, 4) Keep hooks focused and minimal, 5) Avoid complex logic in hooks.
How should error cases be tested?
Error testing practices: 1) Test expected error conditions, 2) Verify error messages and types, 3) Test error handling behavior, 4) Use proper error assertions, 5) Consider edge cases and invalid inputs.
What are best practices for test maintenance?
Maintenance practices: 1) Regular test cleanup, 2) Update tests with code changes, 3) Remove obsolete tests, 4) Maintain test documentation, 5) Refactor tests when needed. Keep tests current and valuable.
How should async tests be structured?
Async test structure: 1) Use async/await consistently, 2) Handle promises properly, 3) Set appropriate timeouts, 4) Test both success and failure cases, 5) Verify async state changes.
What are the patterns for testing complex components?
Complex component patterns: 1) Break down into smaller test cases, 2) Test component integration, 3) Verify state management, 4) Test edge cases, 5) Maintain test isolation.
How should integration tests be organized?
Integration test organization: 1) Group related scenarios, 2) Test component interactions, 3) Verify system integration, 4) Maintain clear test boundaries, 5) Focus on integration points.
What are best practices for snapshot testing?
Snapshot practices: 1) Keep snapshots focused, 2) Review snapshot changes carefully, 3) Update snapshots intentionally, 4) Maintain snapshot readability, 5) Use inline snapshots when appropriate.
How should test coverage be managed?
Coverage management: 1) Set realistic coverage goals, 2) Focus on critical paths, 3) Don't chase 100% blindly, 4) Monitor coverage trends, 5) Use coverage reports effectively.
What are patterns for testing hooks?
Hook testing patterns: 1) Test hook behavior, 2) Verify state changes, 3) Test effect cleanup, 4) Check dependency updates, 5) Test error cases. Use @testing-library/react-hooks.
How should test performance be optimized?
Performance optimization: 1) Minimize test setup, 2) Use efficient assertions, 3) Optimize mock usage, 4) Implement proper test isolation, 5) Use test parallelization effectively.
What are best practices for testing utilities?
Utility testing practices: 1) Test pure functions thoroughly, 2) Cover edge cases, 3) Test input validation, 4) Verify error handling, 5) Maintain function independence.
How should test doubles be managed?
Test double management: 1) Use appropriate double types, 2) Maintain double fidelity, 3) Clean up doubles after use, 4) Document double behavior, 5) Verify double interactions.
What are patterns for testing state management?
State management patterns: 1) Test state transitions, 2) Verify state updates, 3) Test state synchronization, 4) Check state persistence, 5) Test state cleanup.
How should advanced component interactions be tested?
Advanced interaction testing: 1) Test complex user flows, 2) Verify component communication, 3) Test state propagation, 4) Check event handling, 5) Test integration points.
What are patterns for testing microservices?
Microservice testing patterns: 1) Test service boundaries, 2) Verify service communication, 3) Test service isolation, 4) Check service resilience, 5) Test service scaling.
How should complex async workflows be tested?
Async workflow testing: 1) Test workflow steps, 2) Verify state transitions, 3) Test error recovery, 4) Check workflow completion, 5) Test concurrent workflows.
What are best practices for testing distributed systems?
Distributed system practices: 1) Test network partitions, 2) Verify data consistency, 3) Test system recovery, 4) Check system coordination, 5) Test scaling behavior.
How should performance-critical code be tested?
Performance testing practices: 1) Benchmark critical operations, 2) Test resource usage, 3) Verify optimization effectiveness, 4) Test scaling limits, 5) Monitor performance regression.
What are patterns for testing security features?
Security testing patterns: 1) Test authentication flows, 2) Verify authorization rules, 3) Test data protection, 4) Check security boundaries, 5) Test security policies.
How should large test suites be managed?
Large suite management: 1) Organize tests effectively, 2) Implement test categorization, 3) Maintain test independence, 4) Optimize test execution, 5) Monitor test health.
What are best practices for testing data pipelines?
Data pipeline practices: 1) Test data transformations, 2) Verify data integrity, 3) Test pipeline stages, 4) Check error handling, 5) Test pipeline recovery.
How should system integration tests be structured?
System integration structure: 1) Define integration boundaries, 2) Test system interactions, 3) Verify end-to-end flows, 4) Test system resilience, 5) Check system recovery.
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