init: archlens — architecture diagram generator

Hex arch + DDD, tree-sitter parsing, Mermaid/ASCII output.
Supports Rust + Python. 92 tests. CI, diff, --check for staleness detection.

crates/adapters/walkdir/tests/walkdir_discovery_tests.rs

@@ -0,0 +1,71 @@
+use std::fs;
+
+use archlens_domain::{AnalysisConfig, Language, ports::FileDiscovery};
+use archlens_walkdir::WalkdirDiscovery;
+
+fn create_test_tree(dir: &std::path::Path) {
+    fs::create_dir_all(dir.join("src/orders")).unwrap();
+    fs::create_dir_all(dir.join("src/billing")).unwrap();
+    fs::write(dir.join("src/orders/service.rs"), "struct OrderService;").unwrap();
+    fs::write(dir.join("src/orders/model.py"), "class Order: pass").unwrap();
+    fs::write(dir.join("src/billing/invoice.cs"), "class Invoice {}").unwrap();
+    fs::write(dir.join("src/readme.txt"), "not source code").unwrap();
+}
+
+#[test]
+fn discovers_rust_python_and_csharp_files() {
+    let dir = tempfile::tempdir().unwrap();
+    create_test_tree(dir.path());
+
+    let discovery = WalkdirDiscovery::new();
+    let files = discovery
+        .discover(dir.path(), &AnalysisConfig::default())
+        .unwrap();
+
+    assert_eq!(files.len(), 3);
+
+    let languages: Vec<Language> = files.iter().map(|f| f.language()).collect();
+    assert!(languages.contains(&Language::Rust));
+    assert!(languages.contains(&Language::Python));
+    assert!(languages.contains(&Language::CSharp));
+}
+
+#[test]
+fn ignores_non_source_files() {
+    let dir = tempfile::tempdir().unwrap();
+    create_test_tree(dir.path());
+
+    let discovery = WalkdirDiscovery::new();
+    let files = discovery
+        .discover(dir.path(), &AnalysisConfig::default())
+        .unwrap();
+
+    let paths: Vec<&str> = files.iter().map(|f| f.path().as_str()).collect();
+    assert!(!paths.iter().any(|p| p.ends_with(".txt")));
+}
+
+#[test]
+fn respects_exclude_patterns() {
+    let dir = tempfile::tempdir().unwrap();
+    create_test_tree(dir.path());
+
+    let config = AnalysisConfig::default().with_excludes(vec!["billing".to_string()]);
+
+    let discovery = WalkdirDiscovery::new();
+    let files = discovery.discover(dir.path(), &config).unwrap();
+
+    assert_eq!(files.len(), 2);
+    assert!(!files.iter().any(|f| f.path().as_str().contains("billing")));
+}
+
+#[test]
+fn empty_directory_returns_no_files() {
+    let dir = tempfile::tempdir().unwrap();
+
+    let discovery = WalkdirDiscovery::new();
+    let files = discovery
+        .discover(dir.path(), &AnalysisConfig::default())
+        .unwrap();
+
+    assert!(files.is_empty());
+}