# Changelog
All notable changes to SplitRS will be documented in this file.
The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
## [0.3.3] - 2026-07-06
### Added
- **Domain-mapping for `--target-modules`** (`src/domain_router.rs`): seeded assignment (`assign_unlisted = "seeded"` / per-rule `pull_dependencies = true`) pulls items not matched by any rule into the named module with the strongest reference affinity, iterated to a fixpoint; zero-affinity items still fall back to the classic heuristic buckets
- Unknown-name validation for `[[target_modules]]`: an exact (non-glob) `items` pattern that names nothing in the file is now a hard error, with near-miss suggestions
- Dry-run attribution for `--target-modules`: reports which rule (or seed edge) pulled each item into a named module
- Extended `[[target_modules]]` schema: `parent` (route inside a module descended by `--split-nested-mods`), `pull_dependencies`, `doc` (custom `//!` header for the generated module), and per-rule `max_lines` (module overflows into `<name>_2.rs`, `<name>_3.rs`, ... when exceeded)
- Top-level `assign_unlisted = "heuristic" | "seeded"` config/spec-file key
- Infix (`*foo*`) and multi-segment (`a*b*c`) glob patterns for `[[target_modules]]` item matching, in addition to the existing exact/prefix/suffix forms
- `validate_target_modules()`: rejects duplicate module names within the same `parent` scope, rules with an empty `items` list, and catch-all `*` rules that aren't the last rule in their scope
- **Nested inline-mod descent** (`--split-nested-mods`, `--max-mod-depth`, `src/nested_mod_splitter.rs`): recursively splits over-budget inline `mod x { ... }` bodies through the same analyze → group → generate pipeline, emitting `<output>/x/mod.rs` recursively; `super::` paths are depth-adjusted per descent level and absolute spans are preserved so verbatim emission keeps working
- `--facade <glob|named|none>` flag / `[output] facade` config option controlling the re-export style of generated `mod.rs` facades (glob `pub use x::*;`, explicit named re-exports, or declarations only)
- **Verbatim source slicing** (`src/source_map.rs`, public `SourceMap`): maps `proc_macro2::Span` back to exact original source byte ranges so split items — and now also individual extracted impl methods — are emitted byte-for-byte, preserving inline comments and formatting that `prettyplease` would otherwise reflow away
- New integration test suites: `tests/acceptance_e2e_tests.rs`, `tests/domain_mapping_tests.rs`, `tests/nested_mod_tests.rs`
### Changed
- `run_workspace_mode` (`--workspace`) extracted out of `main.rs` into its own bin-only module, `src/workspace_mode.rs`
- `method_analyzer::MethodInfo` gained a `verbatim` field; `ImplBlockAnalyzer::analyze`/`analyze_method` now accept the original source so extracted methods can be emitted verbatim
- `module_generator` extended with `generate_mod_rs_ext`, `item_defined_ident`, `item_visibility`, `deepen_super_in_use`/`deepen_super_in_use_tree`, `public_export_names`, `local_item_names`, `analyze_references`, and `prune_unused_use` to support nested-mod descent and domain routing
- `tests/extract_and_target_tests.rs` extended with additional coverage
- `syn` gained the `visit-mut` feature; added `proc-macro2 = { version = "1", features = ["span-locations"] }` (needed by `source_map.rs`)
- `tokio` updated from 1.52.1 to 1.52.3
- `dashmap` updated from 6.1.0 to 6.2.1
## [0.3.2] - 2026-06-09
### Added
- **SMT-verified function extraction** (new `smt` feature, off by default; `src/extraction/` module):
- `extraction::extract_pure_blocks()` — extracts pure fixed-width-integer sub-blocks from over-budget free functions, committing the extraction only when the OxiZ SMT solver proves semantic equivalence is preserved
- `ExtractionOutcome` enum: `Committed`, `SkippedRefuted` (safety net — rewriter bug caught via counterexample), `SkippedUnsupported`
- Internal pipeline: `detector::find_candidate` (live-variable analysis) → `rewriter::rewrite` (helper synthesis) → `gate::verify_and_decide` (QF_BV proof with whole-function inline-back and componentwise fallback)
- `dataflow.rs` — live-variable dataflow analysis driving the extraction detector
- **SMT equivalence oracle** (`src/smt/` module, feature-gated `smt`):
- `EquivBuilder` — proves two pure fixed-width-integer Rust functions equivalent for all inputs using QF_BV theory via the OxiZ solver; returns `Verified`, `Refuted(Counterexample)`, or `Unsupported`
- `is_pure_supported_expr()` / `is_pure_supported_block()` — non-mutating purity probes with no SMT overhead
- `IntType` and `int_type_of()` — integer-type inference for SMT encoding
- **`splitrs smt-verify-equiv` CLI subcommand** (`src/smt_cli.rs`) — standalone equivalence checker between two Rust function sources
- **Array-splitting mode** (`src/array_splitter.rs`):
- Splits oversized `static`/`const` array literals (data tables) across multiple chunk files using element-level partitioning
- Reconstructs the original `pub static NAME: &[T]` in `mod.rs` via a `const fn` compile-time concatenation (`T: Copy`; type-agnostic, no synthetic default required)
- `analyse_arrays()`, `ArrayItem`, `ArrayAnalysis` public API
- **Test-module splitter** (`src/test_module_splitter.rs`):
- Splits multiple `#[cfg(test)]` / `#[cfg(all(test, ...))]` top-level mod blocks into per-module `tests_NAME.rs` files
- Falls back to classic single `tests.rs` extraction when only one test module is present
- **Editor integrations** (`editors/`):
- Emacs: `splitrs.el` — LSP client configuration with ERT test suite
- IntelliJ: Kotlin plugin (`SplitrsLspServerDescriptor` / `SplitrsLspServerSupportProvider`) with Gradle build
- Neovim: Lua plugin (`lua/splitrs/init.lua`) with nvim-lspconfig-style setup and Busted spec
- VS Code: TypeScript extension (`src/extension.ts`) with `vscode-languageclient` and test suite
- **Config module** (`src/config.rs`): structured `.splitrs.toml` support with `SplitRsConfig`, `NamingConfig`, `OutputConfig`, and `[[target_modules]]` routing rules
- **Helper dependency tracker** (`src/helper_dependency_tracker.rs`) — tracks inter-helper dependencies for smarter module co-location
- New integration test suites: `cross_module_visibility_tests`, `doc_comment_preservation_tests`, `extract_and_target_tests`, `extract_pure_cli_tests`, `extraction_e2e_tests`, `lsp_integration`, `semantic_naming_tests`, `smt_encoder_tests`, `smt_verify_equiv_cli_tests`, `standalone_extraction_tests`, `trait_impl_grouping_tests`
### Changed
- `FileAnalyzer` substantially extended with per-type trait-impl grouping and semantic module naming heuristics
- `module_generator` expanded: per-type `<type>_traits.rs` modules replace the legacy shared `trait_impls.rs`; semantic naming for constants/macros/type-alias buckets
- CLI (`main.rs`) extended with new subcommands, `--smt-verify`, array-split, and test-split flags
- `examples/large_struct.rs`: poisoned-mutex `unwrap()` replaced with `unwrap_or_else(|e| e.into_inner())` (no-unwrap policy)
### Dependencies
- New optional (behind `smt` feature, off by default):
- `oxiz = "0.2.3"` (COOLJAPAN OxiZ SMT solver)
- `num-bigint = "0.4"` (fixed-width integer arithmetic for equivalence proofs)
## [0.3.1] - 2026-04-25
### Added
- **LSP Integration** (`splitrs-lsp` binary, feature-gated `lsp = ["dep:tower-lsp", "dep:tokio", "dep:dashmap"]`, default-on)
- `tower-lsp`-based language server communicating over stdio
- Diagnostics for files exceeding `.splitrs.toml`'s `max_lines` threshold
- Per-impl-block diagnostics when `split_impl_blocks = true` and impl exceeds `max_impl_lines`
- Code action `Refactor with splitrs` (kind `REFACTOR_EXTRACT`) that splits the file and applies a `WorkspaceEdit`
- Hover at file top showing real-time metrics: LoC, method count, max impl size, average cyclomatic complexity
- `.splitrs.toml` config file watch with hot reload via `did_change_watched_files`
- New `[[bin]] splitrs-lsp` entry (required-features = `["lsp"]`) — install with `cargo install splitrs` (default features include LSP)
### Changed
- **Trait Implementation Batching**: trait impls for the same type are now grouped into a single shared module to reduce per-type file clutter (commit 288228f)
- **Accurate Line Count Estimation**: `prettyplease`-formatted output is used to compute line counts, eliminating drift between estimated and final module sizes (commit 288228f)
- **lib.rs Preservation**: when the output target is the crate root, splitrs writes `mod.rs` rather than overwriting an existing `lib.rs` (commit 288228f)
- **Import Deduplication**: `std::collections::*` imports are now deduplicated across split modules (commit 288228f)
### Dependencies
- Added (optional, behind `lsp` feature, enabled by default):
- `tower-lsp = "0.20.0"`
- `tokio = "1.52.1"` (features: `rt-multi-thread`, `macros`, `io-std`, `sync`)
- `dashmap = "6.1.0"`
## [0.3.0] - 2026-02-28
### Added
- **Metrics Dashboard**: New `metrics_dashboard.rs` module for refactoring impact analysis
- Cyclomatic complexity analysis for all methods using AST visitor pattern
- `ComplexityAnalyzer` with `analyze_file()`, `analyze_method()`, `analyze_fn()` methods
- `DashboardGenerator` with HTML, JSON, and text report formats
- HTML reports with embedded CSS, Mermaid dependency graphs, color-coded complexity
- New CLI flags: `--metrics`, `--metrics-output`, `--metrics-format`
- **Macro Analyzer**: New `macro_analyzer.rs` module for macro detection and categorization
- Detects `macro_rules!` definitions with export status and usage counts
- Tracks `#[derive]` usage per type, distinguishing standard vs custom derives
- `MacroPlacement` suggestions for optimal module placement after splitting
- Integrated into `FileAnalyzer` for automatic macro analysis during file processing
- Summary output showing macro counts and custom derives during refactoring
- **Library API Enhanced**: New public modules exposed:
- `pub mod file_analyzer` — file analysis logic
- `pub mod module_generator` — module generation logic
- `pub mod macro_analyzer` — macro analysis
- `pub mod metrics_dashboard` — metrics and reporting
- **Field Access Tracker**: New `FieldAccessTracker` module (579 lines) for tracking field access patterns
- Detects field access across impl blocks for smarter module splitting
- Groups methods that share field access patterns
- Prevents breaking field visibility when splitting modules
- **Trait Method Tracker**: New `TraitMethodTracker` module (205 lines) for tracking trait method usage
- Tracks trait method dependencies across types
- Ensures trait method implementations stay coherent after splitting
### Changed
- **Dependencies Upgraded**:
- `toml`: 0.9 → 1.0 (major version bump)
- `rayon`: 1.10 → 1.11
- **No-Unwrap Policy Compliance**: Eliminated all `unwrap()` usage in production code
- All remaining `unwrap()` calls are confined to `#[cfg(test)]` modules only
- Production code uses proper error handling with `anyhow::Result` throughout
- `FileAnalyzer` now includes `MacroAnalyzer` integration for automatic macro tracking
- **Codebase Statistics**:
- Code: 8,264 lines (↑ 1,053 from 0.2.4)
- Total Rust lines: 10,187 (↑ 1,307 from 0.2.4)
- Total Files: 23 Rust files
### Refactored
- **Main Module Split**: Refactored `main.rs` into separate focused modules following <2000 lines policy
- Extracted `file_analyzer.rs` (707 lines) — file analysis logic
- Extracted `module_generator.rs` (944 lines) — module generation logic
- `main.rs` reduced to 1,222 lines (from previously larger monolith)
- **Module Organization**: All source files now comply with the <2000 lines policy
### Performance
- All existing performance characteristics maintained
- New analyzers add minimal overhead to the analysis pipeline
## [0.2.4] - 2025-12-27
### Added
- **Trait Bound Tracking**: New `TraitBoundAnalyzer` for detecting and preserving trait bounds
- Tracks trait bounds on types and generic parameters
- Detects trait implementations (impl Trait for Type)
- Generates proper trait imports for split modules
- Handles where clauses and complex trait bounds
- Ensures split modules preserve all required trait implementations
- **Private Helper Dependency Tracking**: New `HelperDependencyTracker` for managing helper functions
- Detects private helper function dependencies
- Tracks transitive dependencies (helper calling helper)
- Groups helpers with their callers when splitting modules
- Prevents broken dependencies after refactoring
- Identifies shared helpers used by multiple methods
- **Smart Glob Import Analysis**: New `GlobImportAnalyzer` for handling glob imports (use foo::*)
- Detects glob imports in source files
- Tracks which symbols are actually used from glob imports
- Suggests converting glob imports to specific imports
- Distinguishes between glob-imported and locally-defined symbols
- Generates smarter imports in split modules
- **Library API**: Exposed public API for external usage and testing
- All analyzers now available as library modules
- Comprehensive integration tests for new features
### Changed
- **Test Suite**: Expanded significantly with new analyzers
- **Total Tests**: 183 (75 lib unit + 93 bin unit + 15 integration)
- Added 20 unit tests for new analyzer modules
- Added 6 integration tests for v0.2.4 features
- All tests pass with zero warnings (100% pass rate)
- **Module Organization**: Added three new core analyzer modules
- `trait_bound_analyzer`: 380 lines, 6 unit tests
- `helper_dependency_tracker`: 333 lines, 7 unit tests
- `glob_import_analyzer`: 456 lines, 9 unit tests
- **Codebase Size**: Grew from 5,965 to 8,880 lines (48.9% increase)
- Code: 7,211 lines (↑ 1,221 lines)
- Comments: 401 lines
- Total Files: 26 (↑ 4 files)
### Fixed
- **Critical**: Types with required trait implementations now preserve trait bounds correctly
- **Critical**: Private helper functions are now tracked and moved with their callers
- **Critical**: Glob imports (use foo::*) are now analyzed and handled intelligently
### Performance
- All existing performance characteristics maintained
- New analyzers add minimal overhead to analysis phase
## [0.2.3] - 2025-12-27
### Added
- **Workspace-Level Refactoring**: Process entire Cargo workspaces at once
- Analyze all crates in a workspace
- Identify files exceeding the line limit
- Parallel processing support for faster refactoring
- CLI flags: `--workspace`, `--target <LINES>`
- Workspace summary with crate statistics
- **Parallel Module Generation**: Use multiple threads for faster processing
- Powered by rayon for efficient work-stealing parallelism
- Configurable thread count with `--threads <N>` (0 = auto)
- CLI flag: `--parallel`
- **Enhanced Error Recovery**: Graceful handling of parse errors and failures
- Continue processing remaining files on error (`--continue-on-error`)
- Rollback support for failed operations (`--rollback`)
- Detailed error diagnostics with code snippets and suggestions
- Partial output generation on failure
- Error aggregation with severity levels
- **CI/CD Integration Templates**: Ready-to-use CI/CD configurations
- GitHub Actions workflow (`templates/github-actions.yml`)
- Automated file size checks on PRs
- Refactoring suggestions posted as PR comments
- Code quality reports
- GitLab CI configuration (`templates/gitlab-ci.yml`)
- Pipeline integration for merge requests
- Code quality report generation
- Scheduled weekly analysis jobs
- **New CLI Options**:
- `--workspace`: Enable workspace mode
- `--parallel`: Enable parallel processing
- `--threads <N>`: Number of threads (0 = auto)
- `--continue-on-error`: Continue on parse failures
- `--rollback`: Enable rollback on failure
- `--target <LINES>`: Target line limit for workspace mode
### Changed
- **Test Suite**: Expanded from 62 to 73 tests (64 unit + 9 integration)
- **Dependencies**: Added `rayon = "1.10"` for parallel processing
### Performance
- Parallel processing provides significant speedup for large codebases
- Workspace mode efficiently processes multiple crates concurrently
## [0.2.2] - 2025-12-27
### Added
- **Custom Naming Strategies**: Pluggable naming system for generated modules
- `snake_case` (default): Standard Rust naming conventions
- `domain-specific`: Intelligent naming based on type patterns (Repository, Service, Controller, etc.)
- `kebab-case`: Alternative naming using dashes instead of underscores
- `NamingStrategy` trait for implementing custom naming conventions
- Configuration support via `[naming]` section in `.splitrs.toml`
- Custom type and pattern mappings for domain-specific naming
- **Incremental Refactoring Mode**: Support for refactoring already-split codebases
- Detect existing module structure before refactoring
- Only process new or modified code
- Preserve manual customizations (marked with `// MANUAL:`, `// CUSTOM:`, etc.)
- Smart merge strategies: `smart`, `add-only`, `replace`, `skip-customized`
- CLI flag: `--incremental` with `--merge-strategy` option
- **Integration Test Generation**: Auto-generate verification tests after refactoring
- Verify all types are exported correctly
- Verify method signatures are preserved
- Verify trait implementations are maintained
- CLI flag: `--generate-tests`
- Generates `refactoring_tests.rs` with compile-time checks
- **New CLI Options**:
- `--naming-strategy <NAME>`: Choose module naming strategy
- `--incremental`: Enable incremental refactoring mode
- `--generate-tests`: Generate verification tests
- `--merge-strategy <STRATEGY>`: Merge strategy for incremental mode
### Changed
- **Test Suite**: Expanded from 42 to 62 tests (53 unit + 9 integration)
- **Configuration**: Enhanced `[naming]` section with strategy selection and custom mappings
- **Output**: Statistics now show incremental mode info and skipped modules
### Performance
- All existing performance characteristics maintained
## [0.2.1] - 2025-12-27
### Added
- **Generic Type Parameters Preservation**: Impl blocks now correctly preserve generic parameters, lifetime parameters, and where clauses when split
- **Attribute Preservation**: All impl block attributes (#[cfg], #[allow], #[deny], etc.) are now preserved in split modules
- **Doc Comments Preservation**: Documentation comments on impl blocks are maintained through splitting
- **Long Method Name Handling**: Intelligent truncation and hashing for method names >100 characters
- **Unicode Identifier Support**: Full support for Unicode identifiers with ASCII sanitization for module names
- **Benchmarking Suite**: Comprehensive criterion-based benchmarks for performance testing
- Small file parsing (<100 lines)
- Medium file parsing (100-500 lines)
- Large file parsing (500-2000 lines)
- Code formatting benchmarks
- Generic type parsing
- Scalability testing (10-500 types)
- Trait implementation parsing
- **Integration Test Suite**: 9 comprehensive end-to-end tests covering real-world scenarios
- **Domain-Specific Module Naming**: Intelligent naming based on method patterns:
- `serialization` for serialize/deserialize methods
- `encoding` for encode/decode methods
- `parsing` for parse/parser methods
- `validation` for validate methods
- `rendering` for render/draw methods
- `connections` for connection management
- `caching` for cache-related methods
- `queries` for query/search/find methods
- `authentication` for auth/login/logout methods
- `predicates` for is_/has_/can_ methods
- `crud` for create/read/update/delete methods
- `builders` for with_ methods (builder pattern)
- `event_handlers` for on_ methods
- `accessors` for get_/set_ methods
- **Enhanced Error Messages**: Contextual error messages with actionable suggestions:
- File I/O errors with permission hints
- Parse errors with common causes and solutions
- Configuration errors with example configurations
- **Input Validation**: Comprehensive validation before processing:
- File existence checking
- File type validation (.rs extension warning)
- Directory vs file detection
- **Generated Code Validation**: Automatic syntax checking of generated modules with warnings
- **Enhanced Output**: Beautiful formatted output with statistics, next steps, and backup information
### Fixed
- **Critical**: Generic type parameters not preserved in split impl blocks (Issue #373)
- **Critical**: #[cfg] conditional compilation attributes causing incorrect splitting (Issue #374)
- **Critical**: Lifetime parameters in associated types not handled correctly (Issue #375)
- **High Priority**: Doc comments on impl blocks sometimes lost (Issue #378)
- **High Priority**: Very long method names (>100 chars) breaking module naming (Issue #379)
- **Medium Priority**: Unicode identifiers not fully tested (Issue #380)
- Example files missing `main()` functions (compilation errors fixed)
### Changed
- **Test Suite**: Expanded from 19 to 42 tests (33 unit + 9 integration)
- **Code Quality**: Zero warnings in both dev and release builds
- **Dependencies**: Updated to latest compatible versions:
- syn: 2.0.106 → 2.0.111
- quote: 1.0.41 → 1.0.42
- clap: 4.5.48 → 4.5.53
- toml: 0.9.7 → 0.9.10
- criterion: 0.5.1 → 0.8.1 (dev-dependency)
- **Error Handling**: More informative error messages throughout the codebase
- **Module Generation**: Now includes validation step to catch potential issues early
### Performance
- Benchmarking infrastructure established for tracking performance regressions
- All existing performance characteristics maintained or improved
## [0.2.0] - 2025-10-02
### Added
- Configuration file support (`.splitrs.toml`)
- Trait implementation support with automatic separation
- Type alias resolution in import generation
- Circular dependency detection using DFS algorithm
- Graphviz DOT format export for dependency visualization
- Enhanced preview mode with detailed statistics
- Interactive mode with confirmation prompts
- Automatic backup creation for rollback support
- Smart module documentation generation
### Changed
- Improved scope analysis for better module organization
- Enhanced import generation with context awareness
- Better handling of complex type patterns
### Fixed
- Import generation for nested generic types
- Module organization for types with many trait impls
- Visibility inference for cross-module access
## [0.1.0] - 2025-09-15
### Added
- Initial release
- AST-based parsing with `syn`
- Basic module splitting by line count
- Automatic import generation
- Method dependency analysis
- Basic impl block splitting
- Command-line interface with `clap`
- Documentation and examples
### Features
- Split large Rust files into maintainable modules
- Preserve type definitions and implementations
- Generate proper `mod.rs` with re-exports
- Support for structs, enums, and impl blocks
- Dry-run mode for previewing changes
---
## Version Numbering
SplitRS follows [Semantic Versioning](https://semver.org/):
- **Major version** (x.0.0): Breaking API changes
- **Minor version** (0.x.0): New features, backward compatible
- **Patch version** (0.0.x): Bug fixes, backward compatible
## Links
- [GitHub Repository](https://github.com/cool-japan/splitrs)
- [Crates.io](https://crates.io/crates/splitrs)
- [Documentation](https://docs.rs/splitrs)
- [Issue Tracker](https://github.com/cool-japan/splitrs/issues)