create-react-app

HttpOnly problems Copie paste dont wor

Description This PR adds a new feature to help developers catch common mistakes with environment variables during development. The feature automatically scans source code for references and validates that they are defined in files or the environment. Motivation Currently, when developers reference undefined environment variables in Create React App, they receive no warning until runtime, leading to subtle bugs where is . This feature provides immediate feedback during development to catch these issues early. Key Features ✅ Automatically detects all REACT_APP_ environment variable references in JavaScript and TypeScript files ✅ Warns developers when they reference undefined environment variables ✅ Provides intelligent typo detection with suggestions using Levenshtein distance algorithm (e.g., suggests for ) ✅ Only runs in development mode () - does not affect production builds ✅ Excludes test files from validation since they often use mocked values ✅ Non-blocking - never prevents the dev server from starting ✅ Can be disabled by setting Example Output When a developer references undefined variables: Changes Made 1. Created utility in Implements fuzzy matching for typo suggestions using Levenshtein distance Scans source files using globby Provides clear, actionable error messages with chalk formatting 2. Integrated validation into npm start workflow Added call to in Runs after required file checks but before webpack compilation Non-blocking - always returns true to avoid breaking builds 3. Added comprehensive test suite 11 test cases covering all functionality Tests typo detection, multiple variables, TypeScript support, error handling, etc. All tests passing ✓ 4. Updated documentation Added "Environment Variable Validation" section to Updated with API documentation and usage examples Added feature to package.json files list Testing All tests pass: End-to-end testing confirmed: Warns when variables are undefined Suggests corrections for typos Silent when all variables are defined Can be disabled with Benefits Reduces debugging time by catching environment variable mistakes early Improves developer experience with helpful error messages and suggestions Prevents production bugs caused by undefined environment variables Maintains backward compatibility - optional and non-breaking Follows CRA philosophy* of providing helpful error messages and automatic problem detection Backward Compatibility This feature is: ✅ Non-breaking - only adds warnings, never errors ✅ Optional - can be disabled with ✅ Development-only - no impact on production builds ✅ Respectful of existing workflows - doesn't require any changes to existing code Checklist [x] Tests added and passing [x] Documentation updated [x] Code follows existing style and conventions [x] Feature is non-breaking and optional [x] Works with both JavaScript and TypeScript [x] Handles edge cases gracefully Related Issues This addresses a common pain point mentioned in various issues where developers struggle to debug undefined environment variables. The feature provides immediate, actionable feedback similar to other CRA developer experience improvements.