feat: improve configuration file error handling

Cleans up the error messages generated when errors are encountered in
the configuration file. Instead of showing the raw error message, give
clear information about the problem.

src/commands.rs

@@ -6,7 +6,7 @@ use crate::application::UserData;
 use crate::command::{
     parse, Command, GotoMode, JumpMode, MoveAmount, MoveMode, SeekDirection, ShiftMode, TargetMode,
 };
-use crate::config::Config;
+use crate::config::{user_configuration_directory, Config};
 use crate::events::EventManager;
 use crate::ext_traits::CursiveExt;
 use crate::library::Library;
@@ -25,6 +25,7 @@ use cursive::traits::View;
 use cursive::views::Dialog;
 use cursive::Cursive;
 use log::{debug, error, info};
+use ncspot::CONFIGURATION_FILE_NAME;
 use std::cell::RefCell;
 
 pub enum CommandResult {
@@ -213,7 +214,17 @@ impl CommandManager {
                 Ok(None)
             }
             Command::ReloadConfig => {
-                self.config.reload();
+                self.config.reload().map_err(|_| {
+                    format!(
+                        "Failed to reload configuration. Fix errors in {} and try again.",
+                        user_configuration_directory()
+                            .map(|ref mut path| {
+                                path.push(CONFIGURATION_FILE_NAME);
+                                path.to_string_lossy().to_string()
+                            })
+                            .expect("configuration directory expected but not found")
+                    )
+                })?;
 
                 // update theme
                 let theme = self.config.build_theme();

src/config.rs

@@ -1,4 +1,5 @@
 use std::collections::HashMap;
+use std::error::Error;
 use std::path::PathBuf;
 use std::sync::{RwLock, RwLockReadGuard, RwLockWriteGuard};
 use std::{fs, process};
@@ -195,7 +196,15 @@ impl Config {
     pub fn new(filename: Option<String>) -> Self {
         let filename = filename.unwrap_or(CONFIGURATION_FILE_NAME.to_owned());
         let values = load(&filename).unwrap_or_else(|e| {
-            eprintln!("could not load config: {e}");
+            eprint!(
+                "There is an error in your configuration file at {}:\n\n{e}",
+                user_configuration_directory()
+                    .map(|ref mut path| {
+                        path.push(CONFIGURATION_FILE_NAME);
+                        path.to_string_lossy().to_string()
+                    })
+                    .expect("configuration directory expected but not found")
+            );
             process::exit(1);
         });
 
@@ -256,10 +265,14 @@ impl Config {
         crate::theme::load(theme)
     }
 
-    /// Reload the configuration file.
-    pub fn reload(&self) {
-        let cfg = load(&self.filename).expect("could not reload config");
-        *self.values.write().expect("can't writelock config values") = cfg
+    /// Attempt to reload the configuration from the configuration file.
+    ///
+    /// This only updates the values stored in memory but doesn't perform any additional actions
+    /// like updating active keybindings.
+    pub fn reload(&self) -> Result<(), Box<dyn Error>> {
+        let cfg = load(&self.filename)?;
+        *self.values.write().unwrap() = cfg;
+        Ok(())
     }
 }