improve error handling part 3

src/database/db.rs

@@ -1,30 +1,43 @@
+use core::fmt;
 use mysql::{Opts, Pool, PooledConn};
 use std::{
     env,
+    error::Error,
     path::PathBuf,
     sync::{Arc, Mutex},
 };
 
 use directories::BaseDirs;
 
+#[derive(Debug)]
+struct InitError(String);
+
+impl fmt::Display for InitError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+impl Error for InitError {}
+
 #[derive(Debug)]
 pub struct Db {
     pool: Arc<Mutex<Pool>>,
 }
 
 impl Db {
-    pub fn initialize(env: String) -> Result<Self, mysql::Error> {
-        let base_dir: BaseDirs = match BaseDirs::new() {
-            Some(dirs) => dirs,
-            None => panic!("No config folder found."),
-        };
+    pub fn initialize(env: String) -> Result<Self, Box<dyn std::error::Error>> {
+        let base_dir: BaseDirs = BaseDirs::new()
+            .ok_or_else(|| Box::new(InitError("No config folder found.".to_string())))?;
 
         let config_file_path: PathBuf = base_dir.config_dir().join("rcc/").join(env);
 
-        match dotenv::from_path(config_file_path.as_path()) {
-            Ok(env) => env,
-            Err(_) => panic!("Could not load .env file {:?}", config_file_path.as_path()),
-        };
+        dotenv::from_path(config_file_path.as_path()).map_err(|_| {
+            Box::new(InitError(format!(
+                "Failed to load dotenv file '{}'",
+                config_file_path.display()
+            )))
+        })?;
 
         let location: String = env::var("LOCATION").unwrap_or_else(|_| "localhost".to_string());
         let user: String = env::var("USERNAME").unwrap();

src/repository/file_repo.rs

@@ -15,8 +15,7 @@ impl FileRepo {
     pub fn find_page(&mut self, file_id: &usize) -> Result<Vec<Page>, mysql::Error> {
         let mut connection: mysql::PooledConn = self.db_pool.get_connection()?;
         let stat = connection
-        .prep("SELECT m_id, description, file FROM global_data.effi_file_mapping WHERE file_id = :file_id")
-        .unwrap();
+        .prep("SELECT m_id, description, file FROM global_data.effi_file_mapping WHERE file_id = :file_id")?;
 
         connection.exec_map(
             stat,