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/application/tests/fakes/source_analyzer.rs

@@ -0,0 +1,43 @@
+use std::collections::HashMap;
+
+use archlens_domain::{AnalysisResult, DomainError, SourceFile, ports::SourceAnalyzer};
+
+enum FakeResponse {
+    Success(AnalysisResult),
+    Failure(DomainError),
+}
+
+pub struct FakeSourceAnalyzer {
+    results: HashMap<String, FakeResponse>,
+}
+
+impl FakeSourceAnalyzer {
+    pub fn new() -> Self {
+        Self {
+            results: HashMap::new(),
+        }
+    }
+
+    pub fn with_result(mut self, file_path: &str, result: AnalysisResult) -> Self {
+        self.results
+            .insert(file_path.to_string(), FakeResponse::Success(result));
+        self
+    }
+
+    pub fn with_error(mut self, file_path: &str, error: DomainError) -> Self {
+        self.results
+            .insert(file_path.to_string(), FakeResponse::Failure(error));
+        self
+    }
+}
+
+impl SourceAnalyzer for FakeSourceAnalyzer {
+    fn analyze_file(&self, file: &SourceFile) -> Result<AnalysisResult, DomainError> {
+        let key = file.path().as_str().to_string();
+        match self.results.get(&key) {
+            Some(FakeResponse::Success(result)) => Ok(result.clone()),
+            Some(FakeResponse::Failure(_)) => Err(DomainError::AnalysisError(key)),
+            None => Ok(AnalysisResult::empty()),
+        }
+    }
+}