sapegin/jest-cheat-sheet
Jest Cheat Sheet
Ce projet est un guide de référence complet et une antisèche pour le framework de test Jest. Il fournit une documentation technique et des exemples de syntaxe pour écrire des tests unitaires JavaScript, en se concentrant sur les assertions, les stratégies de mocking et la configuration des suites de tests.
La ressource détaille des méthodes spécifiques pour l'isolation des dépendances et le mocking, incluant l'utilisation de timers fictifs, de substitutions au niveau des modules et la vérification des appels de fonction. Elle couvre également des workflows spécialisés comme le snapshot testing pour détecter les régressions via des comparaisons de sorties sérialisées.
Le guide aborde en outre les patterns de tests asynchrones, les tests pilotés par les données via injection paramétrée, et l'organisation des suites de tests via des procédures de setup et teardown de cycle de vie. Il inclut des instructions pour valider les valeurs de données, vérifier la gestion des exceptions et filtrer l'exécution des tests.
Features
- Testing Framework Cheat Sheets - Serves as a comprehensive reference and cheat sheet for writing and running test suites with Jest.
- Cheat Sheets - Acts as a concise reference guide for Jest assertions, mocking, and test suite configuration.
- Asynchronous Logic Validation - Guides users on verifying promises and asynchronous patterns to ensure assertions execute correctly.
- Dependency Mocking - Provides detailed strategies for isolating code by substituting real modules and functions with mocks.
- Fake Timers - Provides techniques for replacing native clocks with fake timers to execute delayed logic synchronously.
- Asynchronous Test Handling - Offers a comprehensive guide to verifying promises and time-based logic using asynchronous test patterns.
- Dependency Mocking - Provides detailed examples of substituting real module dependencies with programmable mock implementations.
- Timer Mocks - Shows how to control native timer functions to write synchronous tests for time-dependent logic.
- Value Equality Assertions - Offers a reference for validating data values using strict equality, numeric ranges, and string patterns.
- Exception Assertions - Provides syntax for asserting that functions throw specific errors or match expected exception messages.
- Unit Testing - Provides a collection of syntax examples and best practices for writing isolated unit tests in JavaScript.
- Method Interception Spies - Details how to use spies to track object method calls, getters, and setters without altering original behavior.
- Test Suite Organization - Details the organization of test suites using grouping and lifecycle setup and teardown procedures.
- Call-Stack Interceptors - Details how to capture method invocations and arguments using spy functions to verify behavior.
- Data-Driven Testing - Demonstrates how to use parameterized injection to execute a single test template against multiple input sets.
- Function Call Tracking - Shows how to track function invocations, count calls, and inspect arguments passed to mocks.
- Mock State Resetting - Details how to clear internal call history and restore original function implementations between tests.
- Test Parameterization - Demonstrates how to run the same test logic against multiple data sets using parameterized injection.
- Mock Behavior Configuration - Explains how to define return values and sequential responses for mock functions to simulate dependency outcomes.
- Module Registry Resets - Explains how to flush the cached module registry to prevent state leakage between tests.
- Snapshot Testing - Guides the use of serialized output baselines to detect unexpected changes in components or data.
- Snapshot Diffing - Provides instructions for comparing serialized output snapshots to detect regressions via string diffing.
- Mocking and Assertion References - Provides a technical resource for implementing fake timers, module mocks, and data validation.
- Asynchronous Assertions - Provides guidance on using assertions designed to handle the asynchronous lifecycle and prevent tests from finishing prematurely.
- Test Execution Filtering - Explains how to isolate or exclude specific tests from a run to focus on particular features.
- Front End Development - Quick reference for Jest testing framework syntax.
