.golangci.yml

# GolangCI-Lint v2.5 Configuration for coregex - High-Performance Regex Engine
# Documentation: https://golangci-lint.run/docs/configuration/
# AGGRESSIVE CONFIGURATION - Production-quality regex engine with SIMD optimizations

version: "2"

run:
  timeout: 5m
  tests: true

linters:
  # Enable comprehensive set of linters for production-quality code
  enable:
    # Code quality and complexity
    - gocyclo       # Check cyclomatic complexity
    - gocognit      # Check cognitive complexity
    - funlen        # Check function length
    - maintidx      # Maintainability index
    - cyclop        # Check cyclomatic complexity (alternative)
    - nestif        # Reports deeply nested if statements

    # Bug detection
    - govet         # Standard Go vet (includes copylocks!)
    - staticcheck   # Comprehensive static analysis
    - errcheck      # Check that errors are handled
    - errorlint     # Check error wrapping
    - gosec         # Security issues
    - nilnil        # Check that functions don't return nil both ways
    - nilerr        # Check nil error returns
    - nilnesserr    # Check nil error returns patterns
    - ineffassign   # Detect ineffectual assignments

    # Code style and consistency
    - misspell      # Check for misspelled words
    - whitespace    # Check for trailing whitespace
    - unconvert     # Remove unnecessary type conversions
    - unparam       # Detect unused function parameters

    # Naming conventions
    - errname       # Check error naming conventions
    - revive        # Fast, configurable, extensible linter

    # Performance (critical for regex engine)
    - prealloc      # Find slice declarations that could be preallocated
    - bodyclose     # Check HTTP response bodies are closed
    - makezero      # Find slice declarations with non-zero initial length

    # Code practices
    - goconst       # Find repeated strings that could be constants
    - gocritic      # Comprehensive code checker
    - goprintffuncname  # Check printf-like function names
    - nolintlint    # Check nolint directives are used correctly
    - nakedret      # Checks for naked returns

    # Comments and documentation
    # godot disabled - too pedantic for internal comments
    # godox disabled - TODO comments are acceptable during development

    # Additional quality checkers
    - dupl          # Detect duplicate code
    - dogsled       # Check for assignments with too many blank identifiers
    - durationcheck # Check for two durations multiplied together

  settings:
    gosec:
      # Exclude rules that produce false positives in regex engine code:
      # G101: false positive on strategyReasons map (not credentials)
      # G115: rune->byte conversions in UTF-8 encoding are bounded by design
      # G602: slice accesses in range-checked loops are safe
      excludes:
        - G101
        - G115
        - G602

    govet:
      # EXPLICITLY ENABLE copylocks to catch mutex copying issues
      # Critical for DFA cache and concurrent regex matching
      enable:
        - copylocks
      # Disable fieldalignment (memory optimization handled manually for hot paths)
      disable:
        - fieldalignment

    gocyclo:
      # Regex algorithms (DFA construction, NFA simulation) can be complex
      # But keep it reasonable - refactor if exceeding this
      min-complexity: 25

    cyclop:
      # Regex algorithms need higher threshold
      max-complexity: 25

    funlen:
      # SIMD assembly wrappers and DFA search can be long
      lines: 150
      statements: 80

    gocognit:
      # Regex engine algorithms are complex but should be understandable
      min-complexity: 40

    misspell:
      locale: US

    nestif:
      # Max nesting level - keep regex code readable
      min-complexity: 4

    revive:
      # Enable important rules for code quality
      rules:
        - name: var-naming
        - name: error-return
        - name: error-naming
        - name: if-return
        - name: increment-decrement
        - name: var-declaration
        - name: range
        - name: receiver-naming
        - name: time-naming
        - name: unexported-return
        - name: indent-error-flow
        - name: errorf
        - name: empty-block
        - name: superfluous-else
        - name: unreachable-code
        - name: redefines-builtin-id
        # Disabled: exported (stuttering OK for regex types like DFAState)
        # Disabled: package-comments (internal packages don't need)
        # Disabled: unused-parameter (regex funcs may have standard signatures)

    gocritic:
      # Enable important checks
      enabled-tags:
        - diagnostic
        - style
        - performance  # Critical for regex engine performance

      # Disable overly opinionated/experimental checks
      disabled-checks:
        - commentFormatting  # Too opinionated about comment style
        - whyNoLint          # We document nolints when needed
        - unnamedResult      # Named results can reduce readability
        - commentedOutCode   # False positives on test data comments
        - octalLiteral       # 0644 is clearer than 0o644 for file perms
        - paramTypeCombine   # Explicit types clearer in regex code

      settings:
        hugeParam:
          # Regex structs can be large (DFA states, cache, NFA)
          sizeThreshold: 256

  # Exclusions (v2 structure: linters.exclusions.rules)
  exclusions:
    rules:
      # Test files - allow more flexibility
      - path: _test\.go
        linters:
          - gocyclo
          - cyclop
          - funlen
          - maintidx
          - errcheck
          - gosec
          - goconst
          - dupl
          - gocognit

      # SIMD assembly wrappers - can be complex
      - path: simd/memchr.*\.go
        linters:
          - gocyclo      # Assembly dispatch logic
          - funlen       # SIMD wrappers can be long
          - gocognit     # CPU feature detection complexity

      # NFA/PikeVM - hot path with intentional duplication
      - path: nfa/pikevm\.go
        linters:
          - dupl         # addThreadForMatch/addThreadToNextForMatch are intentionally duplicated
          - nestif       # Epsilon closure has nested conditions for performance

      # DFA lazy construction - inherently complex
      - path: dfa/lazy/.*\.go
        linters:
          - gocyclo      # DFA construction is complex
          - cyclop       # DFA determinization complexity
          - gocognit     # Determinization complexity
          - nestif       # DFA logic has nested conditions

      # Prefilter selection - strategy pattern
      - path: prefilter/selector\.go
        linters:
          - gocyclo      # Strategy selection logic
          - nestif       # Decision tree for prefilter

      # Meta-engine orchestration
      - path: meta/.*\.go
        linters:
          - gocyclo      # Engine selection complexity
          - gocognit     # Strategy orchestration
          - nestif       # Multi-engine decision logic
          - funlen       # CompileRegexp and other orchestration functions

      # Literal extraction - complex heuristics
      - path: literal/.*\.go
        linters:
          - gocyclo      # Literal extraction heuristics
          - gocognit     # Pattern analysis complexity

      # Internal utilities
      - path: internal/.*\.go
        linters:
          - revive       # Internal packages, skip naming rules
        text: "var-naming: avoid meaningless package names"

      # Generated files (if any)
      - path: ".*\\.pb\\.go"
        linters:
          - revive
          - gocritic

      # Benchmark code - can be verbose
      - path: benchmark/.*\.go
        linters:
          - funlen       # Benchmark setups can be long
          - gocyclo      # Benchmark complexity acceptable
          - errcheck     # Benchmarks may skip error handling
          - gosec        # Benchmark file operations acceptable

      # Example code - demonstration purposes
      - path: examples?/.*\.go
        linters:
          - errcheck     # Examples may skip error handling for clarity
          - errorlint    # Examples may use %v instead of %w
          - funlen       # Example functions can be longer
          - gocyclo      # Example complexity acceptable
          - cyclop       # Example complexity acceptable
          - gocognit     # Example complexity acceptable
          - godot        # Example comments don't need periods
          - revive       # Examples don't need full documentation
          - gosec        # Examples may have security warnings
          - gocritic     # Example patterns may differ

      # Assembly files dispatcher - platform-specific
      - path: .*_amd64\.go
        linters:
          - gocritic     # Platform-specific patterns
        text: "ifElseChain"

      # SIMD functions may be used only in tests/benchmarks (not production)
      - path: .*_amd64\.go
        linters:
          - unused       # e.g., AVX2 not enabled in integrated prefilter (#74)

issues:
  # Show all issues
  max-issues-per-linter: 0
  max-same-issues: 0

  # Don't hide new issues in existing files
  new: false