v1.0.0

[1.0.0] - 2024-12-27

🎉 Stable Release

nextcov has reached 1.0! This release marks API stability and production readiness.

What nextcov provides:

• V8 code coverage for Next.js and Vite applications with Playwright E2E tests
• Merge Playwright E2E coverage with Vitest unit test coverage
• Support for React Server Components testing through E2E
• Auto-detection of dev mode vs production mode
• Client-only mode for Vite, static sites, and SPAs

Key features:

• nextcov init - Interactive project setup
• nextcov merge - Merge multiple coverage reports
• nextcov check - Detect V8 coverage blind spots and configuration issues

Quality metrics:

• 777 tests passing
• 74% code coverage
• Zero technical debt (no TODO/FIXME markers)
• Strict TypeScript with full type safety
• Professional error handling throughout

Since 0.1.0:

• 12 minor releases with continuous improvements
• Comprehensive documentation with two example projects
• Battle-tested in production applications

v0.12.2

[0.12.2] - 2024-12-27

Added

• Project Configuration Checks in check command - Now scans project configuration in addition to code patterns

  • Separate output sections for "Project Configuration" and "Code Pattern Issues"
  • Severity levels: error (✗), warning (⚠), info (ℹ)

  Configuration checks:

  Check	Severity	Description
  Outdated browserslist	error	Browser targets don't support ?. and ?? (min: chrome 111, edge 111, firefox 111, safari 16.4)
  Babel detected	error	Babel config found (may transpile modern syntax, breaking V8 coverage)
  Playwright not found	error	@playwright/test not in devDependencies (required for nextcov)
  Missing browserslist	warning	No browserslist config - ?. and ?? may be transpiled, causing phantom branches
  Jest detected	warning	Jest config found (consider using Vitest for V8 coverage)
  Source maps not enabled	warning	productionBrowserSourceMaps: true not found in next.config
  Vitest not found	info	Vitest not in devDependencies (recommended for V8 coverage)

• New files:

  • src/linter/detectors/project-config.ts - Project configuration detector
  • src/linter/config-scanner.ts - Configuration scanner wrapper
  • src/linter/detectors/__tests__/project-config.test.ts - Detector tests (20 tests)
  • src/linter/__tests__/config-scanner.test.ts - Scanner tests (7 tests)

• New --skip-config flag for check command - Skip project configuration checks

  npx nextcov check              # config only (no paths)
  npx nextcov check src/         # config + source code
  npx nextcov check src/ --skip-config  # source code only

Changed

• check command behavior - Config is checked by default, source only scanned if paths provided

  • npx nextcov check → config only
  • npx nextcov check src/ → config + source
  • npx nextcov check src/ --skip-config → source only

• check command output - Now shows two sections:

  Project Configuration:
  ─────────────────────────────────────────────────────────
    ✗ Browserslist targets outdated browsers
    ⚠ Jest detected - consider using Vitest for V8 coverage
  
  V8 Coverage Readiness Check
  ═══════════════════════════════════════════════════════════
  ...code pattern issues...
  

• Exit code behavior - Returns 1 if config errors OR code issues found (unless --ignore-patterns)

Tests

• Total tests: 777 passing (up from 742)
• New tests for config detection, scanning, and --skip-config flag

v0.12.1

[0.12.1] - 2024-12-27

Added

• Dependencies - Added for enhanced check command output

  • chalk@^4.1.2 - Terminal color output for ESLint-style formatting

• Documentation - Enhanced README with comprehensive CLI command reference

  • Added "CLI Commands" section documenting all three commands (init, merge, check)
  • Added "Detecting V8 Coverage Blind Spots" section with problem description, solutions, and real-world impact
  • Included before/after code examples showing how to fix blind spots
  • Added CI integration examples for GitHub Actions
  • Documented real-world metrics: refactoring JSX patterns increased trackable branches from 433 to 445 (+12 paths)

Changed

• Console Reporter - Enhanced with colored output using chalk
  • ESLint-style colored output for better readability
  • Bold code snippets in verbose mode
  • Color-coded file paths, warnings, and messages

v0.12.0

[0.12.0] - 2024-12-26

Added

• New check CLI command - Scan codebase for V8 coverage blind spots in JSX code

  • Detects JSX ternary operators: {cond ? <A /> : <B />} that V8 cannot track for branch coverage
  • Detects JSX logical AND operators: {cond && <Component />} that V8 cannot track for branch coverage
  • Only flags patterns inside JSX expression containers ({...}), not variable assignments
  • Usage: npx nextcov check [paths...] [options]
  • Options:
    • --verbose - Show code snippets in console output
    • --json - Output results as JSON
    • --ignore-patterns - Exit with 0 even if issues found (for CI warnings)
  • Returns exit code 0 (clean), 1 (issues found), or 2 (error)
  • Scans .js, .jsx, .ts, .tsx files
  • Automatically ignores node_modules/, .next/, dist/, build/, .git/, coverage/
  • Example: npx nextcov check src/ --verbose

• JSX Pattern Detector - AST-based detection using Babel parser

  • Uses @babel/parser to parse JSX/TypeScript code into AST
  • Uses @babel/traverse to walk AST and find problematic patterns
  • Gracefully handles syntax errors and non-JSX files
  • Tracks parent nodes to distinguish JSX expression containers from variable assignments
  • Extracts code snippets for verbose output
  • Comprehensive test suite with 18 tests (92.68% statement coverage)

• File Scanner - Glob-based directory scanning

  • Scans directories recursively for JS/TS files
  • Supports specific file paths or directory patterns
  • Custom ignore patterns support
  • Relative file path output
  • Comprehensive test suite with 13 tests (95% statement coverage)

• Console Reporter - Formatted output for scan results

  • Human-readable console output with file:line:column locations
  • JSON output mode for programmatic consumption
  • Verbose mode with code snippets
  • Issue grouping by file
  • Help text with remediation guidance
  • Comprehensive test suite with 13 tests (100% coverage)

• Dependencies - Added for JSX pattern detection

  • @babel/traverse@^7.28.5 - AST traversal with visitor pattern
  • @types/babel__traverse@^7.28.0 - TypeScript type definitions

Changed

• CLI bundle size increased - From 74 KB to 80.13 KB (~8% increase)
  • Babel dependencies added for JSX pattern detection (~6 KB impact)
  • Acceptable trade-off for check command functionality

Tests

• Improved test coverage - Added 56 new tests across 4 test files
  • Total tests: 742 passing (up from 686)
  • New test files:
    • src/linter/detectors/__tests__/jsx-patterns.test.ts (18 tests)
    • src/linter/__tests__/scanner.test.ts (13 tests)
    • src/linter/__tests__/reporter.test.ts (13 tests)
    • src/cli/commands/__tests__/check.test.ts (12 tests)
  • Linter module coverage: 98.46% statement, 100% branch, 100% function

v0.11.2

[0.11.2] - 2024-12-26

Changed

• Reduced public API surface for smaller bundle size - Minimized main entry point exports
  • Removed 60+ internal exports from src/index.ts that users should never import directly
  • Removed default value exports (DEFAULT_NEXTCOV_CONFIG, DEFAULT_INCLUDE_PATTERNS, etc.) - only needed internally
  • Removed utility function exports (normalizePath) - only needed internally
  • Kept only 5 essential runtime exports: loadNextcovConfig, resolveNextcovConfig, mergeCoverage, printCoverageSummary, printCoverageComparison
  • Type definitions (NextcovConfig, etc.) remain available for TypeScript users
  • Most users import from nextcov/playwright instead of main entry point
  • Bundle size reduced from 143 KB to 27.28 KB (~81% reduction)
  • Updated README.md API documentation to reflect minimal public API

v0.11.1

[0.11.1] - 2024-12-26

Changed

• Comprehensive codebase reorganization - Restructured entire codebase into focused domain folders for better maintainability and scalability

  • Phase 1 (v0.11.0): Split converter.ts and constants.ts into modular converter/ and parsers/ folders
  • Phase 2: Organized utilities into utils/ folder
    • Moved config.ts, logger.ts, constants.ts, dev-mode-extractor.ts to src/utils/
    • Created utils/index.ts for centralized exports
  • Phase 3: Organized CLI into cli/ folder structure
    • Split cli.ts into cli/commands/merge.ts and cli/index.ts
    • Moved init.ts to cli/commands/init.ts
    • Created cli/index.ts as main CLI entry point
  • Phase 4: Organized core processing modules into core/ folder
    • Moved processor.ts, v8-reader.ts, reporter.ts, sourcemap-loader.ts to src/core/
    • Created core/index.ts for centralized exports
    • Removed unnecessary converter.ts re-export layer
  • Phase 5: Organized worker modules into worker/ folder
    • Moved ast-worker.ts and worker-pool.ts to src/worker/
    • Created worker/index.ts for centralized exports
    • Updated worker path resolution for new dist/worker/ build location
    • Updated tsup config to output workers to dist/worker/
  • Phase 6: Organized merger module into merger/ folder
    • Split merger.ts (968 lines) into 3 focused files:
      • merger/core.ts (842 lines) - CoverageMerger class and merging logic
      • merger/printer.ts (65 lines) - Console output formatting
      • merger/utils.ts (86 lines) - Helper functions and lookups
    • Created merger/index.ts for centralized exports

• Refactored imports to use TypeScript path aliases - Replaced relative imports (../../) with clean @/ prefix

  • Configured TypeScript path aliases in tsconfig.json with @/* mappings
  • Added tsc-alias to build script for path resolution in compiled JavaScript
  • Updated vitest.config.ts with resolve.alias configuration
  • Migrated 35+ files across all modules (cli, core, converter, merger, utils, worker, collector, parsers)
  • Updated dynamic imports and vi.mock paths in CLI commands and tests

Internal

• Build system enhancement - Added tsc-alias step after tsup compilation
  • Build script now: tsup && tsc-alias to resolve path aliases in output
• TypeScript error fixes - Fixed type inference issues in test files
  • Added FileCoverageData type casts to .toJSON() calls in coverage tests
  • Fixed incorrect test assertions with extra parameters
  • Removed non-existent exports (setVerbose, WorkerResult)
• New folder structure - Codebase now organized into 9 domain-focused folders:
  • cli/ - Command-line interface and commands
  • core/ - Core processing modules (processor, reporter, reader, source maps)
  • utils/ - Shared utilities (config, logger, constants, extractors)
  • worker/ - Worker thread parallelization
  • merger/ - Coverage merging logic
  • converter/ - V8-to-Istanbul conversion
  • parsers/ - Bundler-specific URL parsers
  • collector/ - Coverage collection (CDP, dev mode, production)
  • playwright/ - Playwright test fixtures
• All 686 tests passing with full TypeScript type checking
• No API changes - this is purely an internal code organization improvement

v0.11.0

[0.11.0] - 2024-12-26

Changed

• Refactored converter and parsers into modular structure - Split large monolithic files into focused modules for better maintainability
  • Split converter.ts (2,117 lines) into converter/ folder with 4 modules:
    • converter/index.ts - Main CoverageConverter class (1,007 lines)
    • converter/merge.ts - V8 coverage merging (82 lines)
    • converter/sanitizer.ts - Source map sanitization (340 lines)
    • converter/coverage-fixes.ts - Istanbul coverage fixes (754 lines)
  • Created parsers/ folder (6 modules, 553 lines total):
    • Extracted bundler-specific patterns from constants.ts
    • parsers/nextjs.ts - Next.js URL patterns (101 lines)
    • parsers/vite.ts - Vite URL patterns (93 lines)
    • parsers/webpack.ts - Webpack URL patterns (94 lines)
    • parsers/sourcemap.ts - Source map patterns (92 lines)
    • parsers/url-utils.ts - URL utilities (68 lines)
  • Reduced constants.ts from 317 to 92 lines (-71%)
  • All exports remain backward compatible - no breaking changes for users

Internal

• Improved test coverage - Added comprehensive tests for new modules (+2,047 test lines)
  • Coverage improved from 72.75% to 77.53% (+4.78%)
  • Created 9 new test files for parsers and converter modules
  • All 678 tests passing

v0.10.1

[0.10.1] - 2024-12-26

Fixed

• nextcov init now uses pinned dependency versions - cross-env, start-server-and-test, and concurrently now use specific version ranges (^7.0.3, ^2.0.8, ^9.1.0) instead of "latest" for reproducible builds

v0.10.0

[0.10.0] - 2024-12-25

Added

• nextcov init command - Interactive scaffolding for nextcov setup

  • Creates global-setup.ts, global-teardown.ts, and test-fixtures.ts
  • Modifies playwright.config.ts with nextcov configuration
  • Adds npm scripts (dev:e2e, build:e2e, start:e2e, test:e2e, coverage:merge) to package.json
  • Modifies next.config.ts with E2E mode settings for source maps
  • Options: --client-only, --e2e-dir, --js, --force, -y (skip prompts)

• Coverage mode selection in nextcov init - Choose between Full and Client-only modes

  • Full mode: Creates global-setup.ts with server coverage, dev:e2e uses --inspect
  • Client-only mode: Creates global-setup.ts for client coverage, simpler dev:e2e script, collectServer: false in config

• initCoverage() function - Unified entry point for globalSetup

  • Works for both client-only and full (client + server) modes
  • Replaces the confusing pattern of calling startServerCoverage() for client-only mode
  • Example: await initCoverage(config) in global-setup.ts

• Vite support - Client-only coverage for Vite applications

  • Detects Vite source URLs (e.g., http://localhost:5173/src/App.tsx)
  • Use collectServer: false in nextcov config for Vite apps
  • Full example in README under "Vite Support" section

• text-summary in default reporters - Both nextcov init templates and nextcov merge CLI now include text-summary reporter by default

• Component test coverage in merge script - coverage:merge script now includes coverage/component directory

  • Generated script: nextcov merge coverage/unit coverage/component coverage/e2e -o coverage/merged

• --no-strip option for nextcov merge - Disable automatic stripping of import statements and directives

  • By default, merge strips import statements and 'use client'/'use server' directives for accurate merged coverage
  • Use --no-strip to preserve original coverage data

Fixed

• Client-only mode in nextcov init - Fixed several issues with client-only setup

  • dev:e2e script now correctly uses E2E_MODE=true instead of --inspect flag
  • Global teardown template includes correct comment for client-only mode
  • Playwright config correctly sets collectServer: false

• Full mode (client + server) in nextcov init - Fixed server coverage setup

  • start:local script includes NODE_V8_COVERAGE for proper server coverage collection
  • Webpack config properly handles isServer parameter for source map paths
  • Added devtoolModuleFilenameTemplate for accurate server-side source mapping

• Config loading in CJS projects - Fixed loadNextcovConfig() not loading config from playwright.config.ts in projects without "type": "module" in package.json

  • In CJS projects, named exports like export const nextcov = {...} appear under module.default.nextcov instead of module.nextcov
  • Now checks multiple locations: module.nextcov, module.default?.nextcov, and actualConfig?.nextcov

v0.9.4

[0.9.4] - 2024-12-24

Added

• Dual ESM/CJS build - Package now exports both ESM and CommonJS formats
  • ESM: dist/index.js, dist/playwright/index.js
  • CJS: dist/index.cjs, dist/playwright/index.cjs
  • Enables compatibility with tools that require CJS (e.g., Playwright's TypeScript loader when using symlinks via yalc/npm link)
  • Uses tsup bundler for reliable dual-format output

Changed

• Build system migrated to tsup - Replaced tsc with tsup for bundling
  • Adds shims: true for import.meta.url compatibility in CJS
  • Adds cjsInterop: true for proper default export handling
  • Worker file (ast-worker.js) built as separate ESM entry

Fixed

• Worker path resolution for bundled code - findWorkerPath() now checks parent directory for ast-worker.js
  • Fixes worker loading when code is bundled into dist/playwright/ subdirectory
• ESM/CJS interop for ast-v8-to-istanbul - Added runtime detection to unwrap default export in CJS context
  • Fixes (0, import_ast_v8_to_istanbul.default) is not a function error in CJS mode