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