support Dart

[MinhDuy-creator]

Add Dart/Flutter support to LeanKG indexer via tree-sitter-dart.

Cargo.toml - add tree-sitter-dart dependency
src/indexer/mod.rs - add .dart to extension list, new parser slot, filter node_modules
src/indexer/extractor.rs - add Dart test file detection, filter Flutter built-ins (setState, build, context...), support additional node types (mixin, extension, type_alias...), 11 unit tests

[linhdmn]

MR Overview

• Title: support Dart
• Author: MinhDuy-creator
• Branch: feature/support-dart → main

1. Logic Review

Issues Found

• File: src/indexer/extractor.rs:89

  • Severity: warning
  • Issue: tree-sitter-dart crate version is "0.1.0" which may not be stable. Verify the crate is actively maintained.
  • Suggestion: Consider pinning to a specific version or verifying compatibility with tree-sitter parser interface.

• File: src/indexer/extractor.rs:41

  • Severity: info
  • Issue: Dart test file pattern _widget_test.dart - only underscores in filename are considered. Flutter also uses test/widget_test.dart convention.
  • Suggestion: Already handled by path.components().any(|c| c.as_os_str() == "test") check.

• File: src/indexer/extractor.rs:99

  • Severity: info
  • Issue: is_noise_call for Dart includes many keywords (static, final, const, var, extends, implements). These are language keywords, not function calls. However, including them prevents false positives in call relationships.
  • Suggestion: This is acceptable behavior - keywords used as identifiers in some contexts.

2. Scope Validation

✅ In Scope: Dart language support for indexer
✅ Files: src/indexer/mod.rs, src/indexer/extractor.rs, Cargo.toml, Cargo.lock

3. Impact Analysis

• Changed Functions: is_test_file, get_tested_file_path, is_noise_call, extract_* methods
• Affected Modules: indexer (Dart parsing)
• Risk Level: low (additive language support, no breaking changes)
• New Dependency: tree-sitter-dart

4. Deep Scan Findings

✅ Test coverage: 11 new tests for Dart extraction
✅ Node types supported: class, mixin, extension, type_alias, function_signature, constructor_signature

5. Suggested Description Update

## Scope of Changes

### Files Changed
- `Cargo.toml` - Added tree-sitter-dart dependency
- `src/indexer/mod.rs` - Added .dart to extension list, parser slot 6
- `src/indexer/extractor.rs` - Dart test detection, noise call filtering, node type support

### Impact Analysis
- **Affected Modules:** indexer
- **Risk Level:** low
- **New Tests:** 11 (class, mixin, extension, function, method, import, stateful widget)