.csmrc: If present but unreadable, don't continue

This indicates that the user likely intended to use a .csmrc config, but
for some reason it could not be read (e.g. due to permissions). Bail out
early in this case.

Author: relrod

src/csmrc.rs

@@ -24,13 +24,18 @@ impl Config {
             return Ok(Self::default());
         };
         let csmrc_path = home.join(".csmrc");
-        let Ok(csmrc_data) = std::fs::read_to_string(csmrc_path) else {
-            debug!("No .csmrc found, using defaults");
-            return Ok(Config::default());
-        };
-        let config =
-            serde_yaml_ng::from_str(&csmrc_data).map_err(|e| Error::new(ErrorKind::InvalidData, e));
-        debug!("config: {:?}", config);
-        config
+        match std::fs::read_to_string(csmrc_path) {
+            Err(e) if e.kind() == ErrorKind::NotFound => {
+                debug!("No .csmrc found, using defaults");
+                Ok(Config::default())
+            }
+            Err(e) => Err(e),
+            Ok(csmrc_data) => {
+                let config = serde_yaml_ng::from_str(&csmrc_data)
+                    .map_err(|e| Error::new(ErrorKind::InvalidData, e));
+                debug!("config: {:?}", config);
+                config
+            }
+        }
     }
 }

src/env.rs

@@ -93,7 +93,7 @@ pub fn run(config: Config, subcommand: Subcommand) -> ExitCode {
         Subcommand::Create(args) => {
             let Some(env_name) = determine_env_name(args) else {
                 error!("No environment name could be determined. You can specify one with --name");
-                return ExitCode::FAILURE
+                return ExitCode::FAILURE;
             };
             println!("env: {}", env_name);
         }

src/main.rs

@@ -7,7 +7,7 @@ use clap::{Parser, Subcommand};
 use log::{LevelFilter, debug, error, warn};
 use std::fs::File;
 use std::io::Write;
-use std::path::PathBuf;
+use std::path::Path;
 use std::process::ExitCode;
 
 #[derive(Parser, Debug)]
@@ -54,7 +54,11 @@ fn main() -> ExitCode {
 
     if let Err(e) = create_mambarc(&home) {
         let attempted_path = home.join(".mambarc");
-        warn!("Could not create {}, but continuing: {}", attempted_path.display(), e);
+        warn!(
+            "Could not create {}, but continuing: {}",
+            attempted_path.display(),
+            e
+        );
     }
 
     let config = match csmrc::Config::from_csmrc() {
@@ -72,7 +76,7 @@ fn main() -> ExitCode {
 
 /// Create a ~/.mambarc (%UserProfile%\.mambarc on Windows) if it does not
 /// exist.
-fn create_mambarc(home: &PathBuf) -> std::io::Result<()> {
+fn create_mambarc(home: &Path) -> std::io::Result<()> {
     let mambarc = include_str!("../templates/mambarc");
     let mambarc_path = home.join(".mambarc");
     match File::create_new(&mambarc_path) {

src/util.rs

@@ -2,5 +2,8 @@ use std::env;
 use std::path::PathBuf;
 
 pub fn homedir() -> Option<PathBuf> {
-    env::var("HOME").ok().or_else(|| env::var("USERPROFILE").ok()).map(PathBuf::from)
+    env::var("HOME")
+        .ok()
+        .or_else(|| env::var("USERPROFILE").ok())
+        .map(PathBuf::from)
 }