huskies: merge 611_story_extract_settings_service

server/src/service/settings/io.rs

@@ -0,0 +1,52 @@
+//! Settings I/O — the ONLY place in `service/settings/` that may perform side effects.
+//!
+//! Side effects here include: reading/writing `.huskies/project.toml` and
+//! spawning the editor process via `std::process::Command`.
+//! All business logic, branching, and type definitions belong in `mod.rs`,
+//! `project.rs`, or `validate.rs`.
+
+use super::Error;
+use std::path::Path;
+
+/// Read the raw TOML content from `config_path`.
+///
+/// Returns an empty string if the file does not exist yet, so callers can
+/// treat a missing config the same as an empty one.
+///
+/// # Errors
+/// - [`Error::Io`] if the file exists but cannot be read.
+pub(super) fn read_config_toml(config_path: &Path) -> Result<String, Error> {
+    if config_path.exists() {
+        std::fs::read_to_string(config_path).map_err(|e| Error::Io(format!("Read config: {e}")))
+    } else {
+        Ok(String::new())
+    }
+}
+
+/// Write `content` to `config_path`, creating parent directories as needed.
+///
+/// # Errors
+/// - [`Error::Io`] if the directory cannot be created or the file write fails.
+pub(super) fn write_config_toml(config_path: &Path, content: &str) -> Result<(), Error> {
+    if let Some(parent) = config_path.parent() {
+        std::fs::create_dir_all(parent)
+            .map_err(|e| Error::Io(format!("Create .huskies dir: {e}")))?;
+    }
+    std::fs::write(config_path, content).map_err(|e| Error::Io(format!("Write config: {e}")))
+}
+
+/// Spawn the editor process with `file_ref` as the sole argument.
+///
+/// Does not wait for the editor to exit — fire-and-forget so the UI remains
+/// responsive.
+///
+/// # Errors
+/// - [`Error::SpawnError`] if the operating system cannot start the process
+///   (e.g. the editor binary is not on `$PATH`).
+pub(super) fn spawn_editor(editor_command: &str, file_ref: &str) -> Result<(), Error> {
+    std::process::Command::new(editor_command)
+        .arg(file_ref)
+        .spawn()
+        .map(|_| ())
+        .map_err(|e| Error::Spawn(format!("Failed to open editor: {e}")))
+}