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/file-writer/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "archlens-file-writer"
+version = "0.1.0"
+edition = "2024"
+publish = false
+
+[dependencies]
+archlens-domain.workspace = true
+thiserror.workspace = true
+tracing.workspace = true
+
+[dev-dependencies]
+tempfile.workspace = true

crates/adapters/file-writer/src/file_output_writer.rs

@@ -0,0 +1,52 @@
+use std::fs;
+use std::path::PathBuf;
+
+use archlens_domain::{DomainError, RenderOutput, ports::OutputWriter};
+
+pub struct FileOutputWriter {
+    output_path: OutputPath,
+}
+
+enum OutputPath {
+    Directory(PathBuf),
+    File(PathBuf),
+}
+
+impl FileOutputWriter {
+    pub fn new(output_dir: PathBuf) -> Self {
+        Self {
+            output_path: OutputPath::Directory(output_dir),
+        }
+    }
+
+    pub fn single_file(path: PathBuf) -> Self {
+        Self {
+            output_path: OutputPath::File(path),
+        }
+    }
+}
+
+impl OutputWriter for FileOutputWriter {
+    fn write(&self, output: &RenderOutput) -> Result<(), DomainError> {
+        match &self.output_path {
+            OutputPath::File(path) => {
+                if let Some(parent) = path.parent() {
+                    fs::create_dir_all(parent).map_err(|e| DomainError::IoError(e.to_string()))?;
+                }
+                let content = output.files().first().map(|f| f.content()).unwrap_or("");
+                fs::write(path, content).map_err(|e| DomainError::IoError(e.to_string()))?;
+            }
+            OutputPath::Directory(dir) => {
+                fs::create_dir_all(dir).map_err(|e| DomainError::IoError(e.to_string()))?;
+
+                for file in output.files() {
+                    let path = dir.join(file.name());
+                    fs::write(&path, file.content())
+                        .map_err(|e| DomainError::IoError(e.to_string()))?;
+                }
+            }
+        }
+
+        Ok(())
+    }
+}

crates/adapters/file-writer/src/lib.rs

@@ -0,0 +1,3 @@
+mod file_output_writer;
+
+pub use file_output_writer::FileOutputWriter;

crates/adapters/file-writer/tests/file_writer_tests.rs

@@ -0,0 +1,35 @@
+use std::fs;
+
+use archlens_domain::{RenderOutput, RenderedFile, ports::OutputWriter};
+use archlens_file_writer::FileOutputWriter;
+
+#[test]
+fn writes_single_file_to_directory() {
+    let dir = tempfile::tempdir().unwrap();
+    let writer = FileOutputWriter::new(dir.path().to_path_buf());
+
+    let file = RenderedFile::new("arch.mmd", "classDiagram").unwrap();
+    let output = RenderOutput::single(file);
+
+    writer.write(&output).unwrap();
+
+    let content = fs::read_to_string(dir.path().join("arch.mmd")).unwrap();
+    assert_eq!(content, "classDiagram");
+}
+
+#[test]
+fn writes_multiple_files_to_directory() {
+    let dir = tempfile::tempdir().unwrap();
+    let writer = FileOutputWriter::new(dir.path().to_path_buf());
+
+    let files = vec![
+        RenderedFile::new("overview.mmd", "graph TD").unwrap(),
+        RenderedFile::new("orders.mmd", "classDiagram").unwrap(),
+    ];
+    let output = RenderOutput::new(files);
+
+    writer.write(&output).unwrap();
+
+    assert!(dir.path().join("overview.mmd").exists());
+    assert!(dir.path().join("orders.mmd").exists());
+}