# Testing Methodologies Standards for Readability
This document outlines the testing methodologies standards for the Readability project. It provides guidelines for writing effective unit, integration, and end-to-end tests, ensuring the reliability, maintainability, and performance of Readability applications. This document is intended to be used by developers and as a context for AI coding assistants.
## 1. General Testing Principles
### 1.1 Write Testable Code
**Do This:** Design code with testability in mind from the beginning. Use dependency injection, modularity, and clear separation of concerns.
**Don't Do This:** Write monolithic, tightly coupled code that is difficult to isolate and test.
**Why:** Testable code is easier to understand, maintain, and debug. It allows for better isolation of issues, making it simpler to pinpoint the root cause of bugs.
**Example:**
"""python
# Bad: Tightly coupled code
class DataProcessor:
def __init__(self):
self.db_connection = DatabaseConnection() # Hardcoded dependency
def process_data(self, data):
self.db_connection.insert(data)
# ... more processing logic ...
# Good: Dependency Injection
class DataProcessor:
def __init__(self, db_connection):
self.db_connection = db_connection
def process_data(self, data):
self.db_connection.insert(data)
# ... more processing logic ...
class DatabaseConnection:
def insert(self, data):
print(f"Inserting {data} into the database") # Mock implementation
# Example Usage in test:
mock_db = DatabaseConnection() #can mock methods here
processor = DataProcessor(mock_db)
processor.process_data("test_data")
"""
### 1.2 Test Early and Often
**Do This:** Integrate testing into your development workflow. Write tests before or alongside the code being developed (TDD/BDD).
**Don't Do This:** Defer testing until the end of the development cycle.
**Why:** Early testing helps identify bugs sooner, reducing the cost and effort required to fix them. It also promotes better design and clearer understanding of requirements.
### 1.3 Aim for High Code Coverage
**Do This:** Ensure that your tests cover a large portion of your codebase. Use code coverage tools to identify areas that are not adequately tested.
**Don't Do This:** Neglect code coverage, assuming that testing a few key areas is sufficient.
**Why:** High code coverage increases confidence in the correctness of your code. However, coverage should not be the only metric – the quality and effectiveness of the tests are just as important. Focus on covering edge cases, boundary conditions, and complex logic.
### 1.4 Write Clear and Concise Tests
**Do This:** Tests should be easily understandable, well-organized, and focused on a specific aspect of the code. Use descriptive names for test functions and variables.
**Don't Do This:** Write complex, convoluted tests that are difficult to understand or maintain. Avoid long, multi-purpose test functions.
**Why:** Clear tests are easier to debug and maintain. They also serve as documentation for the code being tested.
### 1.5 Follow the Arrange-Act-Assert (AAA) Pattern
**Do This:** Structure your tests according to the Arrange-Act-Assert pattern.
**Don't Do This:** Mix the arrange, act, and assert steps, or omit any of these steps.
**Why:** The AAA pattern provides a clear structure for tests, making them easier to read and maintain. It ensures that each test is focused and well-defined.
* **Arrange:** Set up the test environment, including creating objects, initializing variables, and mocking dependencies.
* **Act:** Execute the code under test.
* **Assert:** Verify the expected outcome.
**Example:**
"""python
import unittest
class StringFormatter:
def capitalize(self, text):
return text.capitalize()
class TestStringFormatter(unittest.TestCase):
def test_capitalize_empty_string(self):
# Arrange
formatter = StringFormatter()
input_string = ""
# Act
result = formatter.capitalize(input_string)
# Assert
self.assertEqual(result, "")
def test_capitalize_single_word(self):
# Arrange
formatter = StringFormatter()
input_string = "hello"
# Act
result = formatter.capitalize(input_string)
# Assert
self.assertEqual(result, "Hello")
"""
## 2. Unit Testing
### 2.1 Focus on Individual Units
**Do This:** Unit tests should focus on testing individual functions, classes, or modules in isolation. Use mocks and stubs to isolate the unit under test from its dependencies.
**Don't Do This:** Write unit tests that depend on external resources, databases, or other services.
**Why:** Unit testing helps identify defects in specific components, making it easier to pinpoint the source of errors. It also allows for faster test execution.
### 2.2 Utilize Mocking and Stubbing
**Do This:** Use mocking and stubbing to replace external dependencies with controlled test doubles. This allows you to isolate the unit under test and simulate various scenarios.
**Don't Do This:** Avoid mocking or stubbing when testing units that interact with external dependencies.
**Why:** Mocking and stubbing provide a deterministic test environment by eliminating the variability introduced by external dependencies. This makes tests more reliable and easier to reproduce.
**Example (Python with "unittest.mock"):**
"""python
import unittest
from unittest.mock import patch
class ExternalService:
def get_data(self):
# Imagine this fetches data from an external source.
raise NotImplementedError
class DataProcessor:
def __init__(self, service):
self.service = service
def process_data(self):
data = self.service.get_data()
return data.upper() # Example processing
class TestDataProcessor(unittest.TestCase):
@patch('your_module.ExternalService') # Assumes ExternalService is defined in your_module.py
def test_process_data(self, MockExternalService):
# Arrange
mock_service = MockExternalService.return_value
mock_service.get_data.return_value = "test data"
processor = DataProcessor(mock_service)
# Act
result = processor.process_data()
# Assert
self.assertEqual(result, "TEST DATA")
mock_service.get_data.assert_called_once()
"""
### 2.3 Test Edge Cases and Boundary Conditions
**Do This:** Thoroughly test edge cases, boundary conditions, and error handling to ensure that the code behaves correctly under unexpected circumstances.
**Don't Do This:** Focus only on happy path scenarios, neglecting to test error handling or boundary conditions.
**Why:** Edge cases and boundary conditions are often the source of bugs. Testing these scenarios helps prevent unexpected behavior in production.
### 2.4 Write Assertions That Provide Meaningful Messages
**Do This:** Write descriptive assertion messages that provide specific information about the failure.
**Don't Do This:** Use generic assertion messages that do not provide enough context for debugging.
**Why:** Meaningful assertion messages make it easier to understand the nature of a test failure and to pinpoint the root cause of the problem.
## 3. Integration Testing
### 3.1 Focus on Interactions Between Components
**Do This:** Integration tests should focus on verifying the interactions between different components or modules within the system.. Mimic real-world workflows, rather than purely functional interactions between classes.
**Don't Do This:** Overlap the scopes between unit and integration tests. Don't test the isolated functionalities, but instead aim for flows that involves several components.
**Why:** Integration testing helps identify issues that arise when different parts of the system are integrated. It ensures that components work together correctly.
### 3.2 Use Real Dependencies Where Appropriate
**Do This:** Use real dependencies (e.g., databases, message queues) in integration tests when it is practical and feasible. Consider using test containers or in-memory databases for faster and more reliable testing.
**Don't Do This:** Mock all dependencies in integration tests. If all dependencies are mocked, it acts more like a unit tests set, reducing the value of the tests.
**Why:** Using real dependencies in integration tests provides a more realistic testing environment. Testing against real-world data stores catches issues with data models, serialization, and database interactions.
### 3.3 Test Data Integrity
**Do This:** Verify that data is correctly passed between components and that data integrity is maintained throughout the integration.
**Don't Do This:** Neglect to validate the consistency and accuracy of data within data stores.
**Why:** Integration tests are critical for ensuring that data is not corrupted or lost as it moves between different components. Data integrity is essential for the proper functioning of the system.
**Example (Testing API endpoint integration):**
"""python
import unittest
import requests
import json
class TestAPIIntegration(unittest.TestCase):
BASE_URL = "http://localhost:8000" # Replace with your API base URL
def test_create_and_retrieve_resource(self):
# Arrange
resource_data = {"name": "Test Resource", "value": 123}
create_url = f"{self.BASE_URL}/resources"
get_url = f"{self.BASE_URL}/resources/1" # Assumes ID 1 will be created
# Act - Create
create_response = requests.post(create_url, json=resource_data)
self.assertEqual(create_response.status_code, 201) # Check creation status
# Act - Retrieve
get_response = requests.get(get_url)
self.assertEqual(get_response.status_code, 200) # Check success
# Assert
retrieved_data = get_response.json()
self.assertEqual(retrieved_data["name"], resource_data["name"])
self.assertEqual(retrieved_data["value"], resource_data["value"])
def test_error_handling(self):
# Arrange
invalid_data = {"invalid_key": True}
url = f"{self.BASE_URL}/resources"
# Act
response = requests.post(url, json=invalid_data)
# Assert
self.assertEqual(response.status_code, 400) # Ensure correct error code
"""
### 3.4 Address Asynchronous and Event-Driven Systems Carefully
**Do This:** Acknowledge the complexities of testing integrations involving async processes or event-driven architectures by building explicit waits or retries into the test suite.
**Don't Do This:** Assume synchronous behavior for the entire integration testing suit.
**Why:** Asynchronous tests often suffer from timing related issues, making the results unreliable.
## 4. End-to-End (E2E) Testing
### 4.1 Simulate Real User Scenarios
**Do This:** End-to-end tests should simulate real user scenarios, covering the entire application workflow from start to finish.
**Don't Do This:** Break E2E workflows into smaller, isolated components.
**Why:** End-to-end testing verifies that the entire system works correctly from the user's perspective. This is crucial for ensuring that the application meets the user's needs.
### 4.2 Test Against Realistic Environments
**Do This:** Run end-to-end tests against environments that closely resemble production. Use real or near-real data.
**Don't Do This:** Run E2E against drastically different, basic environments that do not mirror prod settings.
**Why:** Testing against realistic environments increases confidence that the application will perform as expected in production.
### 4.3 Automate UI Interactions
**Do This:** Use automation frameworks (e.g., Selenium, Cypress, Playwright) to automate user interface interactions in end-to-end tests.
**Don't Do This:** Perform end-to-end tests manually.
**Why:** Automated UI testing is more efficient and reliable than manual testing. It allows for faster test execution and better coverage of the application's functionality.
**Example (Playwright):**
"""python
from playwright.sync_api import sync_playwright
import unittest
class E2ETests(unittest.TestCase):
def setUp(self):
self.playwright = sync_playwright().start()
self.browser = self.playwright.chromium.launch() # or firefox, webkit
self.context = self.browser.new_context()
self.page = self.context.new_page()
self.page.goto("http://localhost:3000") # Replace with app URL
def tearDown(self):
self.page.close()
self.context.close()
self.browser.close()
self.playwright.stop()
def test_login_flow(self):
# Arrange (Assuming a simple login form)
self.page.fill("input[name='username']", "testuser")
self.page.fill("input[name='password']", "testpassword")
# Act
self.page.click("button[type='submit']") # Assumes submit button
# Assert (Check for successful login - e.g., redirect)
self.page.wait_for_url("http://localhost:3000/dashboard", timeout=5000) # Adjust URL/timeout
self.assertEqual(self.page.url, "http://localhost:3000/dashboard")
def test_form_submission(self):
# Arrange
self.page.fill("input[name='name']", "John Doe")
self.page.select_option("select[name='age']", "30")
# Act
with self.page.expect_response("**/submit-form"): # Wait for submission
self.page.click("text=Submit")
# Assert
# Example assertions - adapt to your specific needs
self.assertEqual(self.page.inner_text("div#success-message"), "Form submitted successfully!")
"""
### 4.4 Include UI and API testing.
**Do This:** Make a balance between UI-driven tests and API-driven tests. If a given feature is best tested through API calls, prefer it.
**Don't Do This:** Think only of UI actions whenever doing E2E
**Why:** API E2E runs faster and are more stable.
## 5. Performance Testing
### 5.1 Identify Performance Bottlenecks
**Do This:** Performance tests should identify performance bottlenecks and areas for optimization.
**Don't Do This:** Neglect performance during the development process.
**Why:** Performance testing helps ensure that the application can handle the expected load and provide a good user experience.
### 5.2 Use Load Testing Tools
**Do This:** Use load testing tools (e.g., JMeter, Gatling, Locust) to simulate realistic user traffic and measure application performance under load.
**Don't Do This:** Rely on anecdotal experience or basic spot checks.
**Why:** Load testing helps identify performance issues that may not be apparent under normal usage conditions.
### 5.3 Establish Performance Baselines
**Do This:** Establish performance baselines and track performance metrics over time.
**Don't Do This:** Only perform testing on specific, major modifications. Establish a periodic performance measurement.
**Why:** Tracking performance metrics helps identify performance regressions and ensure that the application continues to meet performance requirements.
## 6. Security Testing
### 6.1 Perform Regular Security Audits
**Do This:** Perform regular security audits (e.g., using automated vulnerability scanners) to identify and address potential security vulnerabilities.
**Don't Do This:** View security as an afterthought.
**Why:** Security testing helps protect the application and its users from security threats.
### 6.2 Test for Common Vulnerabilities
**Do This:** Test for common vulnerabilities such as SQL injection, cross-site scripting (XSS), and cross-site request forgery (CSRF).
**Don't Do This:** Neglect to test the various dimensions of potential threats.
**Why:** Addressing common vulnerabilities helps prevent security breaches and protect sensitive data.
### 6.3 Follow Secure Coding Practices
**Do This:** Adhere to secure coding practices to minimize the risk of introducing security vulnerabilities.
**Don't Do This:** Ignore patterns that favors security.
**Why:** Secure coding practices are essential for building secure applications.
## 7. Continuous Integration and Continuous Deployment (CI/CD)
### 7.1 Integrate Testing into the CI/CD Pipeline
**Do This:** Integrate all types of testing (unit, integration, end-to-end, performance, security) into the CI/CD pipeline.
**Don't Do This:** Keep testing aside of the deployment workflow.
**Why:** CI/CD automates the testing and deployment process, ensuring that changes are thoroughly tested before being released to production.
### 7.2 Automate Test Execution
**Do This:** Automate the execution of all tests as part of the CI/CD pipeline.
**Don't Do This:** Allow manual steps during automated builds.
**Why:** Automated test execution reduces the risk of human error and ensures that tests are run consistently.
### 7.3 Monitor Test Results
**Do This:** Monitor test results and quickly address any failures.
**Don't Do This:** Ignore frequent warnings and failures in the CI/CD suite.
**Why:** Monitoring test results helps ensure that the application remains stable and that new changes do not introduce regressions.
## 8. Advanced Testing Techniques
### 8.1 Property-Based Testing
**Do This:** Consider property-based testing to generate a wide range of inputs and verify that certain properties hold true for the code under test.
**Don't Do This:** Limit the scope of the tests to isolated and deterministic input.
**Why:** Property-based testing can uncover edge cases and boundary conditions that may not be caught by traditional example-based testing.
(Check libraries such as Hypothesis, jqwik, fast-check)
### 8.2 Mutation Testing
**Do This:** Use mutation testing tools to assess the effectiveness of the tests. Mutation testing involves introducing small changes (mutations) to the code and verifying that the tests catch these changes.
**Don't Do This:** Assume that high coverage correlates directly with the quality of testing.
**Why:** Mutation testing provides a metric for the strength of the test suite beyond coverage metrics.
danielsogl
Created Mar 6, 2025
This guide explains how to effectively use .clinerules
with Cline, the AI-powered coding assistant.
The .clinerules
file is a powerful configuration file that helps Cline understand your project's requirements, coding standards, and constraints. When placed in your project's root directory, it automatically guides Cline's behavior and ensures consistency across your codebase.
Place the .clinerules
file in your project's root directory. Cline automatically detects and follows these rules for all files within the project.
# Project Overview project: name: 'Your Project Name' description: 'Brief project description' stack: - technology: 'Framework/Language' version: 'X.Y.Z' - technology: 'Database' version: 'X.Y.Z'
# Code Standards standards: style: - 'Use consistent indentation (2 spaces)' - 'Follow language-specific naming conventions' documentation: - 'Include JSDoc comments for all functions' - 'Maintain up-to-date README files' testing: - 'Write unit tests for all new features' - 'Maintain minimum 80% code coverage'
# Security Guidelines security: authentication: - 'Implement proper token validation' - 'Use environment variables for secrets' dataProtection: - 'Sanitize all user inputs' - 'Implement proper error handling'
Be Specific
Maintain Organization
Regular Updates
# Common Patterns Example patterns: components: - pattern: 'Use functional components by default' - pattern: 'Implement error boundaries for component trees' stateManagement: - pattern: 'Use React Query for server state' - pattern: 'Implement proper loading states'
Commit the Rules
.clinerules
in version controlTeam Collaboration
Rules Not Being Applied
Conflicting Rules
Performance Considerations
# Basic .clinerules Example project: name: 'Web Application' type: 'Next.js Frontend' standards: - 'Use TypeScript for all new code' - 'Follow React best practices' - 'Implement proper error handling' testing: unit: - 'Jest for unit tests' - 'React Testing Library for components' e2e: - 'Cypress for end-to-end testing' documentation: required: - 'README.md in each major directory' - 'JSDoc comments for public APIs' - 'Changelog updates for all changes'
# Advanced .clinerules Example project: name: 'Enterprise Application' compliance: - 'GDPR requirements' - 'WCAG 2.1 AA accessibility' architecture: patterns: - 'Clean Architecture principles' - 'Domain-Driven Design concepts' security: requirements: - 'OAuth 2.0 authentication' - 'Rate limiting on all APIs' - 'Input validation with Zod'
# API Integration Standards for Readability This document outlines the coding standards for integrating Readability with backend services and external APIs. Adhering to these standards will ensure maintainable, performant, and secure code. ## 1. Architectural Patterns for API Integration ### 1.1 Separation of Concerns (SoC) **Standard:** Isolate API integration logic from the core Readability components. **Do This:** * Create dedicated modules or services responsible for API communication. * Use interfaces or abstract classes to define the interaction contracts between Readability and the API integration layer. **Don't Do This:** * Embed API calls directly within UI components or core business logic. * Mix API logic with data transformation or presentation logic. **Why:** SoC enhances maintainability, testability, and reusability. Changes to the API or Readability core will have minimal impact on other parts of the application. **Example:** """python # api_service.py import requests import json from typing import Dict, Any class ApiService: def __init__(self, base_url: str): self.base_url = base_url def get_data(self, endpoint: str, params: Dict[str, Any] = None) -> Dict[str, Any]: """ Fetches data from the API endpoint. """ url = f"{self.base_url}/{endpoint}" try: response = requests.get(url, params=params) response
# Core Architecture Standards for Readability This document outlines the core architecture standards for Readability projects. It provides guidelines for structuring and organizing code to ensure maintainability, scalability, and performance. These standards are designed to work with automated coding assistants such as GitHub Copilot and Cursor. ## 1. Fundamental Architectural Pattern: Modular Monolith ### Standard * **Do This:** Embrace a modular monolith architecture. The Readability application should be structured as a single deployable unit, logically divided into independent modules. * **Don't Do This:** Avoid strict microservices from the start unless demonstrably required by scalability needs. Avoid a tightly coupled monolithic application. ### Explanation A modular monolith offers a balanced approach, providing the benefits of a single codebase (easier deployment, simplified testing) while maintaining logical separation of concerns (improved maintainability, independent development). This pattern allows for future migration to microservices if needed, without premature complexity. ### Code Example (Conceptual) """python # readability/ # ├── core/ # Shared kernel and utilities # ├── article_extraction/ # Module: Article extraction logic # ├── summarization/ # Module: Summarization algorithms # ├── user_management/ # Module: User account management # ├── api/ # API layer exposing functionalities # └── main.py # Entry point, configuration, setup """ ### Anti-Patterns * **Spaghetti Code:** Code that's highly interconnected and difficult to understand. * **God Class:** A single class that handles too many responsibilities. * **Premature Optimization:** Optimizing code before identifying actual performance bottlenecks. ## 2. Project Structure and Organization ### Standard * **Do This:** Organize the project into meaningful modules or packages based on domain or functionality. Enforce clear boundaries between modules through well-defined interfaces/APIs. * **Don't Do This:** Avoid circular dependencies between modules. Avoid scattering related functionality across the project. ### Explanation A well-organized project structure improves code navigation, reduces complexity, and makes it easier for developers to understand and contribute. Clear module boundaries prevent accidental coupling. ### Code Example (Python - Package Structure) """python # readability/ # ├── core/ # │ ├── __init__.py # │ ├── utils.py # General utility functions # │ ├── models.py # Base data models # ├── article_extraction/ # │ ├── __init__.py # │ ├── extractor.py # Core extraction logic # │ ├── parsers.py # HTML parsing implementations # │ ├── schemas.py # Data validation and serialization # │ └── ... # ├── summarization/ # │ ├── __init__.py # │ ├── summarizer.py # Main summarization class # │ ├── algorithms/ # Different summarization algorithms # │ │ ├── lsa.py # │ │ └── ... # │ └── ... # └── ... """ ### Anti-Patterns * **Flat Structure:** Placing all files in a single directory. * **Feature Envy:** A module excessively accesses data or methods of another module. ## 3. Dependency Injection and Inversion of Control ### Standard * **Do This:** Use dependency injection (DI) to manage dependencies between modules. Prefer constructor injection where possible. Utilize an Inversion of Control (IoC) container for complex dependency graphs, if appropriate (e.g. "Flask-DI" for Flask projects). * **Don't Do This:** Avoid hardcoding dependencies within modules. Avoid using global state to share dependencies. ### Explanation DI promotes loose coupling, making modules more testable and reusable. It allows for easy swapping of implementations without modifying the dependent modules. IoC containers manage complex object graphs efficiently. ### Code Example (Python - Constructor Injection) """python # article_extraction/extractor.py class ArticleExtractor: def __init__(self, html_parser): # Dependency injected via constructor self.html_parser = html_parser def extract_content(self, url): html = self.html_parser.fetch_html(url) # ... extract content from HTML using the injected parser return content # core/utils.py class RequestsHTMLParser: def fetch_html(self, url): import requests response = requests.get(url) return response.text # main.py (Example using Flask-DI) from flask import Flask from flask_di import Di from article_extraction.extractor import ArticleExtractor from core.utils import RequestsHTMLParser app = Flask(__name__) di = Di(app) def configure(binder): binder.bind(ArticleExtractor, to=ArticleExtractor(RequestsHTMLParser())) # Binding with app.app_context(): extractor: ArticleExtractor = di.get(ArticleExtractor) #Resolving Dependency """ ### Anti-Patterns * **Service Locator:** Modules explicitly ask a service locator for dependencies, which reduces testability. * **Singleton Abuse:** Using singletons to provide dependencies, which makes it difficult to mock dependencies in tests. ## 4. API Design and Communication ### Standard * **Do This:** Design clear, well-defined APIs for module communication. Use appropriate data serialization formats (e.g., JSON, Protocol Buffers) and API styles (e.g., REST, GraphQL). * **Don't Do This:** Expose internal data structures through APIs. Avoid overly chatty APIs. ### Explanation Well-designed APIs ensure loose coupling between modules and allow for independent evolution. Using appropriate data formats and API styles improves interoperability and performance. ### Code Example (Python - REST API with Flask) """python # api/routes.py from flask import Flask, request, jsonify from article_extraction.extractor import ArticleExtractor from core.utils import RequestsHTMLParser app = Flask(__name__) extractor = ArticleExtractor(RequestsHTMLParser()) @app.route('/extract', methods=['POST']) def extract_article(): url = request.json.get('url') if not url: return jsonify({'error': 'URL is required'}), 400 try: content = extractor.extract_content(url) return jsonify({'content': content}), 200 except Exception as e: return jsonify({'error': str(e)}), 500 if __name__ == '__main__': app.run(debug=True) """ ### Anti-Patterns * **Leaky Abstraction:** The API exposes implementation details. * **Remote Procedure Call (RPC) Abuse:** Using RPC-style APIs for everything, leading to tight coupling. ## 5. Data Management and Persistence ### Standard * **Do This:** Abstract data access logic using a Repository pattern. Use an ORM (e.g., SQLAlchemy) or ODM (e.g., MongoEngine) for database interaction. Define clear data models and schemas. * **Don't Do This:** Directly embed SQL queries within application logic. Expose database implementation details to other modules. ### Explanation The Repository pattern separates data access logic from the business logic, making the application more maintainable and testable. ORMs and ODMs simplify database interactions and provide object-oriented data access. Clear data models ensure data consistency and integrity. ### Code Example (Python - Repository Pattern with SQLAlchemy) """python # core/models.py from sqlalchemy import Column, Integer, String from sqlalchemy.ext.declarative import declarative_base from sqlalchemy.orm import sessionmaker Base = declarative_base() class Article(Base): __tablename__ = 'articles' id = Column(Integer, primary_key=True) url = Column(String) content = Column(String) def __repr__(self): return f"<Article(url='{self.url}', content='{self.content[:50]}...')>" # data/article_repository.py using repository pattern from sqlalchemy import create_engine from sqlalchemy.orm import sessionmaker from core.models import Article, Base class ArticleRepository: def __init__(self, db_url='sqlite:///:memory:'): self.engine = create_engine(db_url) Base.metadata.create_all(self.engine) self.Session = sessionmaker(bind=self.engine) def get_article(self, url): with self.Session() as session: return session.query(Article).filter_by(url=url).first() def add_article(self, url, content): with self.Session() as session: article = Article(url=url, content=content) session.add(article) session.commit() def delete_article(self, url): with self.Session() as session: article = session.query(Article).filter_by(url=url).first() if article: session.delete(article) session.commit() """ ### Anti-Patterns * **Active Record:** Data models directly handle persistence logic, leading to tight coupling. * **Database as API:** Exposing the database directly to client applications. ## 6. Error Handling and Logging ### Standard * **Do This:** Implement comprehensive error handling using exceptions. Log errors and warnings using a logging framework (e.g., "logging" in Python). Use structured logging (e.g. JSON formatted logs). Implement centralized exception handling. * **Don't Do This:** Ignore exceptions. Print error messages to the console without logging. Expose sensitive information in error messages. ### Explanation Robust error handling and logging are crucial for debugging, monitoring, and maintaining the application. Structured logging facilitates analysis and troubleshooting. ### Code Example (Python - Error Handling and Logging) """python import logging import json # Configure logging logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s') def extract_article_info(url): """ Extracts information from a given URL and logs any errors encountered. """ try: # Simulate fetching the HTML content (replace with actual extraction logic) # For example: html_content = fetch_html(url) logging.info(json.dumps({'event': 'article_extraction_started', 'url': url})) # Simulate an error condition raise ValueError("Simulated error during article extraction") article_content = "Dummy article content" logging.info(json.dumps({'event':'article_extraction_success', 'url': url})) # Log extraction success return article_content except ValueError as ve: logging.error(json.dumps({'event': 'article_extraction_failed', 'url': url, 'error': str(ve)}), exc_info=True) return None # Or raise the exception depending on the use case except Exception as e: # Catch-all for any other unexpected errors logging.exception(json.dumps({'event': 'unexpected_error_during_extraction', 'url': url, 'error': str(e)})) #Using logging.exception to capture traceback return None """ ### Anti-Patterns * **Catch-All Exception Handling:** Catching all exceptions without handling them properly. * **Silent Failure:** The application continues to run without reporting an error. ## 7. Concurrency and Parallelism ### Standard * **Do This:** Use appropriate concurrency models (e.g., threads, asyncio) for I/O-bound and CPU-bound tasks. Use thread pools or process pools to manage concurrency. Handle race conditions and deadlocks carefully. * **Don't Do This:** Use global state in concurrent code without proper synchronization. Create too many threads or processes, leading to resource exhaustion. ### Explanation Concurrency and parallelism can significantly improve application performance, but they also introduce complexities. Choosing the right concurrency model and handling synchronization issues are crucial. ### Code Example (Python - Asyncio for Concurrent Web Requests) """python import asyncio import aiohttp async def fetch_url(session, url): try: async with session.get(url
# Component Design Standards for Readability This document outlines the component design standards for Readability, focusing on creating reusable, maintainable, and performant components within the Readability framework. These standards are designed to promote consistency across the codebase and ensure that all components adhere to best practices. ## 1. Component Architecture Principles ### 1.1. Single Responsibility Principle (SRP) * **Standard:** Each component should have one, and only one, reason to change. A component should encapsulate a specific functionality or logic. * **Why:** This principle ensures that components are modular and easier to understand, test, and maintain. It reduces the risk of unintended side effects when modifications are made. * **Do This:** Break down complex functionalities into smaller, independent components. Ensure that each component is responsible for a well-defined task. * **Don't Do This:** Create monolithic components that handle multiple unrelated tasks. Avoid components with high coupling and low cohesion. **Example:** """python # Good: Separate components for data fetching and UI rendering class DataFetcher: def fetch_data(self, url): # Fetch data from URL pass class DataRenderer: def render_data(self, data): # Render data in the UI pass # Bad: Single component handling both data fetching and rendering class DataComponent: def fetch_and_render(self, url): # Fetch data from URL # Render data in the UI pass """ ### 1.2. Open/Closed Principle (OCP) * **Standard:** Components should be open for extension but closed for modification. You should be able to add new functionality without altering the source code of existing components. * **Why:** This principle promotes stability and reduces the risk of introducing bugs when adding new features. It encourages the use of abstraction and polymorphism. * **Do This:** Use interfaces, abstract classes, or higher-order functions to allow for extension without modification. * **Don't Do This:** Directly modify existing component code to add new features. Avoid tightly coupled designs that require changes across multiple components. **Example:** """python # Good: Using interface for extension from abc import ABC, abstractmethod class ReportGenerator(ABC): @abstractmethod def generate_report(self, data): pass class PDFReportGenerator(ReportGenerator): def generate_report(self, data): # Generate PDF report pass class CSVReportGenerator(ReportGenerator): def generate_report(self, data): # Generate CSV report pass # Bad: Modifying existing class to add new report format class ReportGenerator: def generate_report(self, data, format): if format == "pdf": # Generate PDF report pass elif format == "csv": # Generate CSV report pass """ ### 1.3. Liskov Substitution Principle (LSP) * **Standard:** Subtypes must be substitutable for their base types without altering the correctness of the program. * **Why:** Ensures that inheritance maintains the expected behavior of base classes. This is especially important for maintaining the integrity of polymorphic code. * **Do This:** Ensure that derived classes fulfill the contract of their base classes. Avoid implementing methods that throw exceptions in derived classes if the base class does not specify that behavior. * **Don't Do This:** Create derived classes that violate the behavior of their base classes. Avoid forcing users to write type-checking code to handle different subtypes. **Example:** """python # Good: Subtype maintains base type behavior class Rectangle: def __init__(self, width, height): self.width = width self.height = height def set_width(self, width): self.width = width def set_height(self, height): self.height = height class Square(Rectangle): def __init__(self, size): super().__init__(size, size) def set_width(self, width): self.width = width self.height = width def set_height(self, height): self.width = height self.height = height # Bad: Subtype violates base type behavior class Dog: def bark(self): print("Woof!") class RobotDog(Dog): def bark(self): raise NotImplementedError("Robot dogs cannot bark.") """ ### 1.4. Interface Segregation Principle (ISP) * **Standard:** Clients should not be forced to depend on methods they do not use. * **Why:** Reduce unnecessary dependencies and promote loose coupling. Makes components easier to change and reuse. * **Do This:** Break down large interfaces into smaller, more specific interfaces tailored to the needs of different clients. * **Don't Do This:** Create large "fat" interfaces that force clients to implement methods they don't need. **Example:** """python # Good: Segregated interfaces from abc import ABC, abstractmethod class Document(ABC): @abstractmethod def open(self): pass @abstractmethod def close(self): pass class Printable(ABC): @abstractmethod def print_document(self): pass class Scanner(ABC): @abstractmethod def scan_document(self): pass class SimpleDocument(Document): def open(self): pass def close(self): pass class MultiFunctionPrinter(Document, Printable, Scanner): def open(self): pass def close(self): pass def print_document(self): pass def scan_document(self): pass # Bad: Single, monolithic interface class Machine(ABC): @abstractmethod def print_document(self, document): pass @abstractmethod def fax_document(self, document): pass @abstractmethod def scan_document(self, document): pass class OldFashionMachine(Machine): # must implement unrelated actions def print_document(self, document): pass # This method is not relevant but must be implemented def fax_document(self, document): pass def scan_document(self, document): pass """ ### 1.5. Dependency Inversion Principle (DIP) * **Standard:** High-level modules should not depend on low-level modules. Both should depend on abstractions. Abstractions should not depend on details. Details should depend on abstractions. * **Why:** Reduce coupling between components. Allows for easier testing, maintenance, and flexibility in changing implementations. * **Do This:** Use interfaces or abstract classes to define dependencies between components. Inject dependencies into components rather than creating them internally. * **Don't Do This:** Allow high-level modules to directly depend on low-level modules. Avoid hardcoding dependencies within components. **Example:** """python # Good: Using dependency injection through an interface from abc import ABC, abstractmethod class Switchable(ABC): @abstractmethod def turn_on(self): pass @abstractmethod def turn_off(self): pass class LightBulb(Switchable): def turn_on(self): print("LightBulb: ON") def turn_off(self): print("LightBulb: OFF") class ElectricPowerSwitch: def __init__(self, client: Switchable): self.client = client self.on = False def press(self): if self.on: self.client.turn_off() self.on = False else: self.client.turn_on() self.on = True # Bad: High-level module depends directly on low-level module. class LightBulb: def turn_on(self): print("LightBulb: ON") def turn_off(self): print("LightBulb: OFF") class ElectricPowerSwitch: def __init__(self, bulb: LightBulb): self.bulb = bulb self.on = False def press(self): if self.on: self.bulb.turn_off() self.on = False else: self.bulb.turn_on() self.on = True """ ## 2. Component Structure and Organization ### 2.1. Directory Structure * **Standard:** Organize components into logical directories based on their functionality or domain. Group related components together. * **Why:** Improves code discoverability and maintainability. Makes it easier to navigate and understand the codebase. * **Do This:** Create descriptive directory names that reflect the purpose of the components within them. Use a consistent directory structure across the project. * **Don't Do This:** Place all components in a single directory. Use ambiguous or non-descriptive directory names. **Example:** (Illustrative directory structure for a hypothetical Readability plugin) """ readability_plugin/ ├── core/ # Core components related to the central functionality │ ├── __init__.py │ ├── text_analyzer.py # Analyze text complexity │ ├── readability_scorer.py # Calculate the score. │ └── ... ├── ui/ # User interface components │ ├── __init__.py │ ├── settings_panel.py │ ├── display_panel.py │ └── ... ├── data/ # Data storage and processing │ ├── __init__.py │ ├── model.py # Data models of information │ ├── data_persistence.py # Load/Save function │ └── ... ├── tests/ # Automated tests │ ├── __init__.py │ ├── test_text_analyzer.py │ └── ... ├── README.md └── setup.py """ ### 2.2. Component Naming * **Standard:** Use descriptive and consistent names for components. Follow a naming convention that reflects the component's purpose and type. * **Why:** Improves code readability and maintainability. Makes it easier to understand the role of each component. * **Standard (Python):** Use CamelCase for Classes. Use snake_case for function names. **Example:** """python # Good class TextAnalyzer: # Class name descriptive and in CamelCase def calculate_flesch_reading_ease(self, text): # snake_case for function # Bad class TA: def calc(self, input): ... """ ### 2.3. Component Size * **Standard:** Keep components small and focused. Avoid creating large, complex components that are difficult to understand and maintain. * **Why:** Improves code readability and maintainability. Makes it easier to test and reuse components. * **Do This:** Break down large components into smaller, more manageable pieces. Limit the number of lines of code in a single component. * **Don't Do This:** Create monolithic components with hundreds or thousands of lines of code. ## 3. Component Implementation Details ### 3.1. Immutability * **Standard:** Favor immutable data structures and components. If a component's state is fixed after creation, it is easier to reason about and test. * **Why:** Simplifies debugging and testing. Reduces the risk of unexpected side effects. Improves concurrency. * **Do This:** Use immutable data structures (e.g., tuples, frozensets). Create components that do not modify their internal state after initialization. **Example:** """python # Good: Using immutable tuple def calculate_stats(data): # data should be kept immutable average = sum(data) / len(data) minimum = min(data) maximum = max(data) return (average, minimum, maximum) # Returning a tuple # Bad: Mutating data directly def update_data(data): data[0] = 100 # Mutating the input """ ### 3.2. Error Handling * **Standard:** Implement robust error handling within components. Catch exceptions and handle them gracefully. Provide meaningful error messages. * **Why:** Prevents unexpected crashes and provides helpful information for debugging. Improves the robustness of the application. * **Do This:** Use try-except blocks to catch exceptions. Raise custom exceptions with descriptive error messages. **Example:** """python def read_file(filename): try: with open(filename, 'r') as f: content = f.read() return content except FileNotFoundError: raise ValueError(f"File not found: {filename}") except IOError: raise IOError(f"Could not read file: {filename}") """ ### 3.3. Logging * **Standard:** Use logging to record important events and errors within components. Provide sufficient context to diagnose issues. Make sure log configuration is abstracted via central configuration file * **Why:** Aids in debugging and monitoring the application. Provides valuable insights into component behavior. * **Do This:** Use a logging framework to record events. Include relevant information such as timestamps, component names, and error messages. "logging.basicConfig(filename='example.log', encoding='utf-8', level=logging.DEBUG)" should only be called from a central configuration point. **Example:** """python import logging # Create a logger logger = logging.getLogger(__name__) logger.setLevel(logging.DEBUG) # Create handlers stream_handler = logging.StreamHandler() # Output to console formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s') stream_handler.setFormatter(formatter) logger.addHandler(stream_handler) def process_data(data): try: result = 10 / len(data) logger.debug(f"Processed data: {result}") return result except ZeroDivisionError: logger.error("Cannot divide by zero", exc_info=True) # Include exception info return None """ ### 3.4. Testing * **Standard:** Write unit tests for all components. Ensure that each component is thoroughly tested in isolation. Apply Test Driven Design (TDD) where tests are defined upfront * **Why:** Validates the correctness of components. Prevents regressions and ensures that components continue to function as expected after modifications. * **Do This:** Use a unit testing framework. Write tests for all possible scenarios, including edge cases and error conditions. **Example:** """python # example_component.py def add(x, y): return x + y # test_example_component.py import unittest from example_component import add class TestExampleComponent(unittest.TestCase): def test_add_positive_numbers(self): self.assertEqual(add(2, 3), 5) def test_add_negative_numbers(self): self.assertEqual(add(-2, -3), -5) def test_add_mixed_numbers(self): self.assertEqual(add(2, -3), -1) """ ### 3.5. Documentation * **Standard:** Document all components with clear and concise descriptions. Explain the purpose, inputs, outputs, and any dependencies of each component. * **Why:** Improves code understanding and maintainability. Makes it easier for other developers to use and contribute to the codebase. * **Do This:** Use docstrings to document components. Provide examples of how to use components. * **Standard (Python):** Follow PEP 257 for docstring conventions. **Example:** """python def calculate_reading_time(text, words_per_minute=200): """ Calculates the estimated reading time for a given text. Args: text (str): The text to analyze. words_per_minute (int): The average reading speed in words per minute. Default is 200. Returns: float: The estimated reading time in minutes. Example: >>> calculate_reading_time("This is a short sentence.") 0.025 """ word_count = len(text.split()) return word_count / words_per_minute """ ### 3.6. Performance Optimization * **Standard:** Optimize components for performance. Minimize unnecessary computations and allocations. * **Why:** Improves the responsiveness and efficiency of the application. Reduces resource consumption. * **Do This:** Use efficient algorithms and data structures. Avoid unnecessary loops and function calls. Profile components to identify performance bottlenecks. * **Don't Do This:** Premature optimization. Optimize only when necessary and based on profiling results. **Example:** """python # Avoid string concatenation in loops def build_string(items): result = "" # Inefficient for item in items: result += str(item) return result def build_string(items): return "".join(map(str,items)) # Efficient """ ### 3.7 Security Considerations * **Standard:** Build components with security in mind. Sanitize inputs and outputs. Avoid vulnerabilities such as SQL injection and cross-site scripting (XSS). * **Why:** Protects the application and its users from malicious attacks. Ensures data integrity and confidentiality. * **Do This:** Use secure coding practices. Follow security guidelines and recommendations. Perform security reviews and penetration testing. * **Don't Do This:** Trust user inputs. Store sensitive data in plain text. **Example:** """python import html import bleach def sanitize_input(user_input): # Escape HTML entities to prevent XSS escaped_input = html.escape(user_input) # Use bleach to allow only specific tags and attributes allowed_tags = ['p', 'a', 'b', 'i', 'strong', 'em'] allowed_attributes = {'a': ['href', 'title']} sanitized_input = bleach.clean(escaped_input, tags=allowed_tags, attributes=allowed_attributes) return sanitized_input # Usage Example: user_supplied_html = "<script>alert('XSS Attack!')</script><p>This is some text with a <a href='http://example.com'>link</a></p>" safe_html = sanitize_input(user_supplied_html) print(safe_html) # Output: <p>This is some text with a <a href='http://example.com'>link</a></p> """ ### 3.8. Code Reviews * **Standard:** Always conduct thorough code reviews for all component changes. * **Why:** Catches errors and ensures standards adherence early in the development cycle. Promotes knowledge sharing among team members. * **Do This:** Use a code review tool. Provide constructive feedback. Focus on code quality, maintainability, and security. Document review discussions. ## 4. Readability-Specific Considerations ### 4.1. Linguistic Analysis Components * **Standard**: Separate the components for each type of analysis and its level needed for readability * **Why**: Readability needs to be scalable from the analysis. **Example**: """python # Good class SentenceAnalyzer: def get_words(sentence): pass def get_length(self, sentence): pass class TextAnalyzer: def get_sentences(text): pass def get_average_words(text): pass # Bad class Analyzer: def get_words_from_sentence(sentence): pass def get_sentences_from_text(text): pass def get_average_words_from_text(text): pass """ ### 4.2. Scoring Components * **Standard**: Clearly define scores and use cases. * **Why**: Readability needs to specify the range of score and what each score means **Example**: """python class FleschKincaid: def getScoreMeaning(score): if (score > 100): return "Easy to read. " # keep it simple, link to documentation for details if (score <= 100 and score >=60): return "Can be read by 6th graders" # keep it simple, link to documentation for details def calculate(text): # specific implementation pass """ ## 5. Modern Approaches and Patterns ### 5.1. Functional Components * **Standard:** Favor functional components where appropriate. This is especially relevant for data transformation or analysis logic where state management is minimal. * **Why:** Functional components are often easier to test, reason about, and compose. They can lead to more concise and maintainable code. * **Do This:** Use pure functions (no side effects), immutability, and higher-order functions. * **Don't Do This:** Force a functional approach when an object-oriented approach would be more natural. **Example:** """python # Functional component for calculating readability score (simplified) def calculate_fog_index(average_words_per_sentence, percentage_complex_words): return 0.4 * (average_words_per_sentence + percentage_complex_words) # Example usage: avg_words = 15.5 complex_words_percent = 10.0 fog_index = calculate_fog_index(avg_words, complex_words_percent) print(f"Fog Index: {fog_index}") """ ### 5.2. Hooks and Composition * **Standard:** Utilize modern composition techniques such as hooks (if applicable or available in the Readability context) to share logic between components. * **Why:** Promotes code reuse and avoids duplication. Leads to more flexible and maintainable components. * **Do This:** Identify common patterns in components and extract them into reusable hooks or functions. **Example:** Demonstrative hooks style: """python # Example hook-like function for reusability def use_fetch_data(url): """ Simulates a hook for fetching data from a URL. In React/similar frameworks, this would be a true hook. """ try: # Simulate fetching data (replace with actual API call) import time time.sleep(1) #Simulate network latency data = f"Data from {url}" # Placeholder return data, None # Return data and no error except Exception as e: return None, str(e) # Return no data and an error message def display_component(url): """Example display component using our hook-like function""" data, error = use_fetch_data(url) if error: return f"Error: {error}" else: return f"Displaying: {data}" # Usage result = display_component("https://example.com/readability_data") print(result) """ By adhering to these component design standards, developers can create a more maintainable, testable, and performant Readability codebase. These standards should be reviewed and updated regularly to reflect the latest best practices and advancements in the field.
# State Management Standards for Readability This document outlines the coding standards for state management in Readability applications. It provides guidelines for structuring state, handling data flow, and ensuring reactivity, while emphasizing maintainability, performance, and security. These standards are designed to be used by developers and AI coding assistants. ## Architecture and General Principles ### Standard 1: Embrace Unidirectional Data Flow * **Do This:** Implement a unidirectional data flow architecture. Changes to the state should originate from actions/events, flow through reducers/updaters, and propagate to the UI. * **Don't Do This:** Avoid directly mutating state values from UI components. This creates unpredictable behavior and makes debugging difficult. * **Why:** Unidirectional data flow ensures predictability and simplifies debugging. It provides a clear audit trail of state changes. """javascript // Example: Actions const READ_ARTICLE = 'READ_ARTICLE'; function readArticle(articleId) { return { type: READ_ARTICLE, payload: articleId }; } // Example: Reducer function articleReducer(state = {}, action) { switch (action.type) { case READ_ARTICLE: return { ...state, currentlyReading: action.payload }; default: return state; } } // Example: Component function ArticleList({ articles, readArticle }) { return ( <ul> {articles.map(article => ( <li key={article.id} onClick={() => readArticle(article.id)}> {article.title} </li> ))} </ul> ); } """ ### Standard 2: Centralize Application State * **Do This:** Use a centralized state container (e.g., using Readability's built-in state management or integrating with external libraries like Zustand or Jotai). * **Don't Do This:** Avoid scattering state across multiple components, especially using prop drilling for deeply nested components. * **Why:** Centralization makes it easier to track and manage state, reduce redundancy, and improve component decoupling. """javascript // Example: Zustand (using Readability compatible syntax) import create from 'zustand' const useStore = create(set => ({ articles: [], currentlyReading: null, fetchArticles: async () => { const response = await fetch('/api/articles'); // Example API endpoint const data = await response.json(); set({ articles: data }); }, setCurrentlyReading: (articleId) => set({ currentlyReading: articleId }) })) function ArticleList() { const { articles, fetchArticles, setCurrentlyReading } = useStore(); useEffect(() => { fetchArticles(); }, [fetchArticles]); return ( <ul> {articles.map(article => ( <li key={article.id} onClick={() => setCurrentlyReading(article.id)}> {article.title} </li> ))} </ul> ); } """ ### Standard 3: Favor Immutability * **Do This:** Treat state as immutable. Use methods that return new objects or arrays instead of modifying existing ones. * **Don't Do This:** Directly mutate state objects or arrays (e.g., using "push", "splice", or direct assignment). * **Why:** Immutability makes it easier to track changes, detect updates, and implement features like time-travel debugging. It is also crucial for performance optimization in Readability's rendering engine. """javascript // Example: Immutable update using spread operator function reducer(state, action) { switch (action.type) { case 'ADD_ARTICLE': return { ...state, articles: [...state.articles, action.payload] }; case 'UPDATE_ARTICLE': return { ...state, articles: state.articles.map(article => article.id === action.payload.id ? { ...article, ...action.payload } : article ) }; default: return state; } } // Example: Immutable update using libraries like Immer import { produce } from "immer" const articleReducer = (state, action) => { return produce(state, draft => { switch (action.type) { case "ADD_ARTICLE": draft.articles.push(action.payload) break case "REMOVE_ARTICLE": draft.articles = draft.articles.filter(article => article.id !== action.payload) break; default: return; //Important for Immer } }) } """ ### Standard 4: Selectors for Data Retrieval * **Do This:** Use selectors to derive data from the global state. Selectors should be pure functions. * **Don't Do This:** Access state directly in components or perform complex data transformations inline. * **Why:** Selectors help encapsulate the structure of the state, improve performance by memoizing derived data, and simplify component logic. """javascript // Example: Selector function const getPublishedArticles = (state) => { return state.articles.filter(article => article.isPublished); }; // Example: Using selector in a component function PublishedArticleList({ articles }) { const publishedArticles = useSelector(getPublishedArticles); // Assuming a useSelector hook return ( <ul> {publishedArticles.map(article => ( <li key={article.id}>{article.title}</li> ))} </ul> ); } """ ### Standard 5: Asynchronous Actions and Side Effects * **Do This:** Manage asynchronous actions (e.g., API calls) using middleware (e.g., Readability's effect handlers, or a library like Redux Thunk or Redux Saga). * **Don't Do This:** Perform asynchronous operations directly in components or reducers. * **Why:** Middleware keeps components and reducers pure and testable, and provides a structured way to handle side effects. """javascript // Example: Readability effect function fetchArticlesEffect(dispatch) { return async () => { try { const response = await fetch('/api/articles'); const data = await response.json(); dispatch({ type: 'FETCH_ARTICLES_SUCCESS', payload: data }); } catch (error) { dispatch({ type: 'FETCH_ARTICLES_ERROR', payload: error }); } }; } // Example: Dispatching the effect function ArticleList({ dispatch, isLoading, error, articles }) { useEffect(() => { dispatch(fetchArticlesEffect); // Assuming dispatch comes from context }, [dispatch]); // ... rendering logic } """ ## Technology-Specific Standards within Readability Readability, depending on the chosen ecosystem (e.g., tight integration with a custom framework or leveraging established JavaScript libraries), might have distinct approaches to state management. The following considerations are crucial : ### Readability Built-in State Management * **Leverage Readability's Context API effectively:** For simple state management needs, Readability's Context API offers a straightforward solution. When using Context, ensure that value updates trigger re-renders only when necessary. """javascript // Example: Using Context API import React, { createContext, useState, useContext } from 'react'; const ArticleContext = createContext(); export function ArticleProvider({ children }) { const [articles, setArticles] = useState([]); const fetchArticles = async () => { const response = await fetch('/api/articles'); const data = await response.json(); setArticles(data); }; const value = { articles, fetchArticles, }; return ( <ArticleContext.Provider value={value}> {children} </ArticleContext.Provider> ); } export function useArticles() { return useContext(ArticleContext); } // Usage in a component: function ArticleList() { const { articles, fetchArticles } = useArticles(); useEffect(() => { fetchArticles(); }, [fetchArticles]); return ( <ul> {articles.map(article => ( <li key={article.id}>{article.title}</li> ))} </ul> ); } """ * **Reducer Hooks for Complex State:** For component-specific state logic involving multiple sub-values with interdependencies or complex update logic, favor "useReducer" over multiple "useState" calls. """javascript // Example: useReducer Hook import React, { useReducer } from 'react'; const initialState = { articles: [], loading: false, error: null, }; function reducer(state, action) { switch (action.type) { case 'FETCH_ARTICLES_START': return { ...state, loading: true, error: null }; case 'FETCH_ARTICLES_SUCCESS': return { ...state, loading: false, articles: action.payload }; case 'FETCH_ARTICLES_ERROR': return { ...state, loading: false, error: action.payload }; default: return state; } } function ArticleList() { const [state, dispatch] = useReducer(reducer, initialState); useEffect(() => { const fetchArticles = async () => { dispatch({ type: 'FETCH_ARTICLES_START' }); try { const response = await fetch('/api/articles'); const data = await response.json(); dispatch({ type: 'FETCH_ARTICLES_SUCCESS', payload: data }); } catch (error) { dispatch({ type: 'FETCH_ARTICLES_ERROR', payload: error }); } }; fetchArticles(); }, []); // ... rendering with state.articles, state.loading, state.error } """ ### Using External State Management Libraries * **Choose the Right Library:** Select a state management library that aligns with the application's complexity and team's expertise. Options include Zustand, Jotai, Redux. * **Zustand and Jotai:** These are often preferable for simpler applications due to their ease of use and smaller bundle size compared to Redux. """javascript //Example with Jotai (using Readability friendly syntax) import { atom, useAtom } from 'jotai' const articlesAtom = atom([]) const ArticleList = () => { const [articles, setArticles] = useAtom(articlesAtom) useEffect(() => { const fetchArticles = async () => { const response = await fetch('/api/articles'); const data = await response.json(); setArticles(data); }; fetchArticles(); }, [setArticles]); return ( <ul> {articles.map(article => ( <li key={article.id}>{article.title}</li> ))} </ul> ); } """ * **Redux (If Needed):** For large, complex applications, Redux might be necessary. Use Redux Toolkit to streamline Redux development """javascript //Example using Redux Toolkit import { configureStore, createSlice } from '@reduxjs/toolkit'; import { useDispatch, useSelector } from 'react-redux'; const articlesSlice = createSlice({ name: 'articles', initialState: { articles: [], loading: false, error: null, }, reducers: { fetchArticlesStart: (state) => { state.loading = true; state.error = null; }, fetchArticlesSuccess: (state, action) => { state.loading = false; state.articles = action.payload; }, fetchArticlesError: (state, action) => { state.loading = false; state.error = action.payload; }, }, }); export const { fetchArticlesStart, fetchArticlesSuccess, fetchArticlesError } = articlesSlice.actions; export const store = configureStore({ reducer: { articles: articlesSlice.reducer, }, }); //Async Thunk Example export const fetchArticles = () => async (dispatch) => { dispatch(fetchArticlesStart()); try { const response = await fetch('/api/articles'); const data = await response.json(); dispatch(fetchArticlesSuccess(data)); } catch (error) { dispatch(fetchArticlesError(error.message)); } }; function ArticleList() { const dispatch = useDispatch(); const { articles, loading, error } = useSelector((state) => state.articles); useEffect(() => { dispatch(fetchArticles()); }, [dispatch]); // ... rendering logic using articles, loading, error } """ * **Middleware for Side Effects (Redux):** When using Redux, leverage middleware like "redux-thunk" or "redux-saga" to handle asynchronous operations and side effects cleanly. * **Selectors (Redux):** Always use selectors to access data from the Redux store. This allows components to remain decoupled from the store's precise state structure. ### Standard 6: Optimistic Updates * **Do This:** Implement optimistic updates to provide a more responsive user experience. Assume the operation will succeed and update the UI immediately, reverting the update only if an error occurs. * **Don't Do This:** Wait for the server response before updating the UI, leading to perceived lag. * **Why:** Optimistic updates make the application feel faster and more interactive. """javascript // Example: Optimistic update with Zustand import create from 'zustand' const useArticleStore = create((set, get) => ({ articles: [], addArticle: async (newArticle) => { // Optimistically update set(state => ({ articles: [...state.articles, { ...newArticle, tempId: Date.now(), isOptimistic: true }] })); try { const response = await fetch('/api/articles', { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(newArticle), }); if (response.ok) { const savedArticle = await response.json(); // Replace temp article with the real one set(state => ({ articles: state.articles.map(article => article.tempId === newArticle.tempId ? savedArticle : article ) })); } else { // Revert on error set(state => ({ articles: state.articles.filter(article => article.tempId !== newArticle.tempId) })); } } catch (error) { // Revert on error set(state => ({ articles: state.articles.filter(article => article.tempId !== newArticle.tempId) })); } }, })) function ArticleForm() { const addArticle = useArticleStore(state => state.addArticle); const handleSubmit = (event) => { event.preventDefault(); const title = event.target.title.value; const content = event.target.content.value; addArticle({ title, content }); }; return ( <form onSubmit={handleSubmit}> <input type="text" name="title" placeholder="Title" /> <textarea name="content" placeholder="Content"></textarea> <button type="submit">Add Article</button> </form> ); } """ ### Standard 7: Local Storage and Persistence * **Do This:** Use local storage or other persistence mechanisms sparingly and carefully, primarily for user preferences or caching data. * **Don't Do This:** Store sensitive information in local storage without proper encryption. Avoid excessively large data storage, as it can impact performance. * **Why:** Local storage can improve the user experience by preserving state across sessions. However, it introduces security risks if not handled properly and can degrade performance if overused. """javascript // Example: Storing user preference in local storage function useThemePreference() { const [theme, setTheme] = useState(() => { return localStorage.getItem('theme') || 'light'; }); useEffect(() => { localStorage.setItem('theme', theme); }, [theme]); return [theme, setTheme]; } function ThemeSwitcher() { const [theme, setTheme] = useThemePreference(); const toggleTheme = () => { setTheme(theme === 'light' ? 'dark' : 'light'); }; return ( <button onClick={toggleTheme}> Switch to {theme === 'light' ? 'Dark' : 'Light'} Theme </button> ); } """ ### Standard 8: Server-Side State Management * **Do This:** When using Readability in server-side rendered or statically generated applications, consider carefully which state needs to be persisted and how it should be managed (e.g., using techniques like rehydration). * **Don't Do This:** Assume client-side state management strategies translate directly to server-side environments. * **Why:** Proper server-side state management impacts initial render performance, SEO, and overall application architecture. """javascript // Example: Rehydrating Zustand state from server (Next.js example) import { useStore } from './store'; // Assuming Zustand store import { useSnapshot } from 'valtio'; //Valtio for simple state sharing function MyApp({ Component, pageProps }) { if (pageProps.initialZustandState) { useStore.setState(pageProps.initialZustandState); } return <Component {...pageProps} />; } export default MyApp; export async function getStaticProps() { // Fetch data from external API const res = await fetch('https://.../articles') const data = await res.json() return { props: { initialZustandState: useStore.getState(), // Pass the store snapshot to the page articles: data }, revalidate: 10, } } //Example Component function ArticleList({articles}) { const store = useSnapshot(useStore); return ( <ul> {store.articles.map(article => ( <li key={article.id}>{article.title}</li> ))} </ul> ); } """ ## Common Anti-Patterns * **Prop Drilling:** Passing props through multiple layers of components that don't need them. Use context or a centralized state management solution instead. * **Global Mutable State:** Relying on global variables or objects directly modified throughout the application. This makes it difficult to track state changes and causes unpredictable behavior. * **Over-reliance on "useState":** Using multiple "useState" hooks in a component with complex state logic. This can lead to verbose and difficult-to-manage code. Consider using "useReducer" or a custom hook instead. * **Ignoring Memoization:** Failing to memoize derived data or component outputs, leading to unnecessary re-renders and performance issues. Utilize "useMemo", "useCallback", and "React.memo" effectively. * **Direct DOM Manipulation:** Directly manipulating the DOM outside of component lifecycles or effect hooks. This bypasses Readability's rendering engine and causes inconsistencies. By adhering to these state management standards, developers can build robust, maintainable, and performant Readability applications. These guidelines promote predictability, simplify debugging, and ensure a consistent and scalable architecture. They also facilitate collaboration and code reuse within development teams.
# Performance Optimization Standards for Readability This document outlines coding standards specifically for performance optimization in Readability projects. Adhering to these standards will ensure application speed, responsiveness, and efficient resource usage, leading to a better user experience. ## 1. Architectural Considerations for Performance ### 1.1. Data Structures and Algorithms **Standard:** Choose appropriate data structures and algorithms based on performance characteristics (time and space complexity) and the specific requirements of the Readability components. * **Do This:** Analyze algorithmic complexity before implementation. Use profilers to identify performance bottlenecks. Select data structures that align with access patterns (e.g., use a hash map for fast lookups). * **Don't Do This:** Blindly use simple data structures like arrays/lists for complex operations without considering their performance implications. Neglect assessing the efficiency of complex algorithms. **Why:** Efficiency in data handling directly translates to faster processing within Readability, minimizing latency and maximizing throughput. Slow operations can impact the perception of readability and negatively impact engagement. **Code Example (Python):** """python # Inefficient (O(n) lookup) my_list = ["apple", "banana", "cherry"] if "banana" in my_list: print("Banana found") # Efficient (O(1) lookup) my_set = {"apple", "banana", "cherry"} if "banana" in my_set: print("Banana found") """ **Anti-Pattern:** Using linear search when a binary search (requires a sorted data structure) or a hash table lookup would be more efficient. ### 1.2. Caching Strategies **Standard:** Implement caching at different levels (e.g., browser, server, database) to reduce redundant computations and data retrieval. * **Do This:** Use browser caching for static assets (CSS, JavaScript, images). Implement server-side caching for frequently accessed data or computed results. Consider using a content delivery network (CDN) for content distribution. Utilize database caching mechanisms (e.g., query caching). * **Don't Do This:** Cache indiscriminately. Improper cache invalidation can lead to stale data. Omit cache expiration policies, allowing caches to grow indefinitely. **Why:** Caching minimizes latency and server load, enhancing responsiveness and scalability of Readability. **Code Example (Server-side caching with Redis using Python and Flask):** """python from flask import Flask, jsonify import redis import time app = Flask(__name__) redis_client = redis.Redis(host='localhost', port=6379, db=0) def get_expensive_data(key): """Simulates an expensive operation (e.g., database query).""" time.sleep(2) # Simulate delay return f"Data for {key} - generated at {time.time()}" @app.route('/data/<key>') def data_endpoint(key): cached_data = redis_client.get(key) if cached_data: print("Data retrieved from cache") return jsonify({"data": cached_data.decode('utf-8')}) #Important to decode from bytes data = get_expensive_data(key) redis_client.setex(key, 60, data) # Cache for 60 seconds print("Data retrieved from source and cached") return jsonify({"data": data}) if __name__ == '__main__': app.run(debug=True) """ **Anti-Pattern:** Neglecting cache invalidation, leading to users seeing outdated information. Setting excessive cache times without a proper invalidation strategy. ### 1.3. Asynchronous Processing and Concurrency **Standard:** Use asynchronous processing and concurrency to handle long-running tasks effectively, preventing blocking operations on the main thread/process. * **Do This:** Leverage asynchronous frameworks like "asyncio" (Python) for I/O-bound operations. Utilize thread pools or process pools for CPU-bound operations. Employ message queues (e.g., RabbitMQ, Kafka) for decoupling tasks. * **Don't Do This:** Block the main thread/process with synchronous operations. Overuse threads/processes, leading to context-switching overhead and resource contention. Ignore potential race conditions and deadlocks when using concurrency. **Why:** Asynchronous processing improves responsiveness, especially in scenarios involving network requests, file processing, or computationally intensive analysis within Readability. **Code Example (Asynchronous processing with "asyncio" in Python):** """python import asyncio import time async def fetch_data(item): """Simulates fetching data (e.g., from a URL).""" print(f"Fetching data for {item}...") await asyncio.sleep(1) # Simulate network latency print(f"Data fetched for {item}") return f"Data: {item} at {time.time()}" async def process_items(items): """Processes a list of items concurrently.""" tasks = [fetch_data(item) for item in items] results = await asyncio.gather(*tasks) # Run tasks concurrently return results async def main(): items = ["Item1", "Item2", "Item3"] results = await process_items(items) for result in results: print(result) if __name__ == "__main__": asyncio.run(main()) """ **Anti-Pattern:** Performing computationally expensive tasks within the main event loop, causing UI freezes. Improperly managing concurrency leading to data corruption. ### 1.4 API Design **Standard**: Design APIs for efficiency, focusing on minimizing data transfer and optimizing server-side processing. Consider GraphQL over REST for greater flexibility in requesting specific data, reducing over-fetching. * **Do This**: Implement pagination for large datasets. Support filtering and sorting at the API level. Use data compression techniques. Rate limit API requests. * **Don't Do This**: Return excessive or unnecessary data in API responses. Make the client perform filtering/sorting when the server can handle it more efficiently. Neglect security considerations when designing APIs. **Why**: Efficient APIs reduce network bandwidth usage and improve server-side processing time directly impacting the perceived speed and efficiency of the Readability platform. **Code Example (Node.js with Express and pagination):** """javascript const express = require('express'); const app = express(); const items = Array.from({length: 100}, (_, i) => "Item ${i+1}"); // create 100 items app.get('/items', (req, res) => { const page = parseInt(req.query.page) || 1; // default to page 1 const limit = parseInt(req.query.limit) || 10; // default to 10 items per page const startIndex = (page - 1) * limit; const endIndex = page * limit; const results = {}; if (endIndex < items.length) { results.next = { page: page + 1, limit: limit }; } if (startIndex > 0) { results.previous = { page: page - 1, limit: limit }; } results.results = items.slice(startIndex, endIndex); res.json(results); }); app.listen(3000, () => console.log('Server started on port 3000')); """ **Anti-Pattern**: Returning full datasets when only a subset is needed. Making redundant API calls. Omitting error handling. ## 2. Code-Level Optimization ### 2.1. Memory Management **Standard:** Optimize memory usage to prevent memory leaks and excessive memory consumption. * **Do This:** Profile memory usage to identify memory leaks. Use garbage collection mechanisms efficiently. Free unused resources promptly. Avoid creating unnecessary objects. Employ data structures that minimize memory footprint. * **Don't Do This:** Create large, persistent objects without proper management. Forget to release resources (e.g., file handles, database connections). Accidentally hold references to objects, preventing garbage collection. **Why:** Efficient memory management prevents application crashes, reduces GC overhead, and improves overall performance. Especially on systems with limited resources (mobile or embedded systems). **Code Example (Python):** """python import gc def process_data(data): """Processes a large dataset.""" temp_list = [item * 2 for item in data] # List comprehension # ... perform operations on temp_list ... del temp_list # Explicitly delete to release memory gc.collect() # Force garbage collection (optional, but can be useful) data = list(range(1000000)) process_data(data) """ **Anti-Pattern:** Accumulating large amounts of data in memory without releasing it, leading to OutOfMemoryError. Creating unnecessary object copies. ### 2.2. String Handling **Standard:** Handle strings efficiently, minimizing string concatenation and object creation. * **Do This:** Use string builders or efficient string concatenation methods instead of repeatedly concatenating strings with the "+" operator (especially in loops). Avoid unnecessary string conversions. Utilize string interning where appropriate. * **Don't Do This:** Use inefficient string concatenation techniques. Create excessive temporary string objects. Perform redundant string operations. **Why:** String operations can be performance-intensive. Efficient string handling reduces memory allocation and improves processing speed. **Code Example (Java):** """java // Inefficient String result = ""; for (int i = 0; i < 1000; i++) { result += "Iteration " + i; } // Efficient StringBuilder sb = new StringBuilder(); for (int i = 0; i < 1000; i++) { sb.append("Iteration ").append(i); } String result = sb.toString(); """ **Anti-Pattern:** Using repeated string concatenation with the "+" operator within loops, leading to O(n^2) complexity. Unnecessary string conversions. ### 2.3. Loop Optimization **Standard:** Optimize loops and iterations for performance, minimizing unnecessary computations and improving cache locality. * **Do This:** Minimize computations within loops. Use loop unrolling or vectorization techniques (if supported by the language/platform). Optimize inner loops first. Ensure proper indexing and avoid out-of-bounds access. * **Don't Do This:** Perform redundant computations within loops. Ignore loop invariants. Access memory in a non-sequential manner. **Why:** Loops are often critical performance bottlenecks. Optimizing loops can significantly improve application speed. **Code Example (Python with NumPy):** """python import numpy as np # Inefficient (Python loop) a = [i for i in range(1000000)] b = [i*2 for i in range(1000000)] result = [] for i in range(len(a)): result.append(a[i] + b[i]) # Efficient (NumPy vectorization) a = np.arange(1000000) b = np.arange(1000000) * 2 result = a + b """ **Anti-Pattern:** Performing the same calculation repeatedly within a loop. Using inefficient loop constructs. ### 2.4. Regular Expressions **Standard**: Use regular expressions carefully, understanding their performance implications. Compile regular expressions for reuse. Avoid overly complex regex patterns. * **Do This**: Compile regular expressions for repeated use (especially within loops). Use specific patterns instead of overly generic ones. Test regex performance with representative data. * **Don't Do This**: Use overly complex regular expressions that can lead to catastrophic backtracking. Create regular expressions dynamically within loops. **Why:** Inefficient regular expressions can be extremely slow and CPU-intensive. **Code Example (Python):** """python import re # Inefficient: Recompiling the regex on each call. def find_matches_inefficient(text, pattern): return re.findall(pattern, text) # Efficient: Compiling the regex once and reusing it. compiled_pattern = re.compile(r'\d+') # Example pattern: matches one or more digits def find_matches_efficient(text, compiled_pattern): return compiled_pattern.findall(text) text = "This is a string with some numbers like 123 and 456." matches1 = find_matches_efficient(text, compiled_pattern) print(matches1) #Output: ['123', '456'] matches2 = find_matches_efficient("Another string 789", compiled_pattern) print(matches2) # Output: ['789'] """ **Anti-Pattern**: Using very complex regular expressions to parse highly structured data: consider a dedicated parser instead. Forgetting to escape special characters properly leading to unexpected behavior. ## 3. Framework and Technology-Specific Optimizations ### 3.1. Readability Specific Module Optimization **Standard**: When working with Readability modules (or any third party plugins or frameworks), understand how to efficiently use their facilities. Use profiling tools to see which modules are creating bottlenecks. * **Do This**: Use modules sparingly, only importing what is needed. Investigate specific module's best practices for optimal performance (example: If using a database connector, use connection pooling). Lazy Load Modules when appropriate. * **Don't Do This**: Import entire modules when only a small part is needed. Neglect to read the documentation on module performance and resource usage. **Why**: Minimizing the dependency footprint and leveraging best practices specific to your chosen modules improves overall application performance. **Code Example (Python):** *(This is a general example, replace with specific Readability module usage)* """python # Instead of: # import readability_module # readability_module.HeavyFunction1() # readability_module.HeavyFunction2() # Do: # from readability_module import HeavyFunction1, HeavyFunction2 # HeavyFunction1() # HeavyFunction2() """ **Anti-Pattern**: Blindly importing entire packages, leading to unnecessary overhead. Ignoring the specific performance recommendations of selected modules. ### 3.2: Front-End Optimization (If Applicable) While the core of Readability might focus on server-side logic; if there's a front-end component it is important to consider these aspects: * **Minification and Bundling**: Minify CSS and JavaScript files to reduce file sizes. Bundle multiple files into fewer requests. * **Image Optimization**: Optimize images for the web using appropriate formats (WebP, JPEG, PNG) and compression techniques. Use responsive images. * **Lazy Loading**: Lazy load images and other assets that are not immediately visible. * **Browser Caching**: Leverage browser caching appropriately. **Why**: Optimizing the front-end improves page load times and responsiveness, leading to better user engagement. ## 4. Profiling and Monitoring ### 4.1. Performance Profiling **Standard:** Use profiling tools to identify performance bottlenecks and areas for optimization. * **Do This:** Use CPU profilers, memory profilers, and I/O profilers. Profile code in representative environments. Analyze profiling data to identify hotspots. Use profiling to measure the impact of optimizations. * **Don't Do This:** Optimize code without profiling. Rely on intuition alone. Ignore performance metrics. **Why:** Profiling provides data-driven insights into performance bottlenecks, guiding optimization efforts effectively. **Code Example (Using "cProfile" in Python):** """python import cProfile import pstats def my_function(): """A function to profile.""" # ... code to profile ... pass cProfile.run('my_function()', 'profile_output') p = pstats.Stats('profile_output') p.sort_stats('cumulative').print_stats(20) # Display top 20 functions by cumulative time """ **Anti-Pattern:** Guessing at performance bottlenecks without empirical evidence. Neglecting to use available profiling tools. ### 4.2. Performance Monitoring **Standard:** Implement monitoring to track application performance in production environments. * **Do This:** Track key performance indicators (KPIs) such as response time, throughput, error rate, and resource usage. Set up alerts for performance degradation. Use monitoring tools to analyze performance trends. Integrate monitoring into your deployment pipeline. * **Don't Do This:** Deploy code without monitoring. Ignore performance alerts. Fail to analyze performance trends. **Why:** Monitoring provides visibility into application performance, enabling early detection of issues and proactive optimization. This comprehensive Performance Optimization Standards document helps ensure the Readability project consistently achieves high levels of performance, speed, and efficiency. The examples provided serve as starting points; always adapt these to the specific contexts of your Readability development.