Allow returning errors

minigrep/src/main.rs

@@ -1,4 +1,5 @@
 use std::env;
+use std::error::Error;
 use std::fs;
 use std::process;
 
@@ -16,11 +17,10 @@ fn main() {
     run(config);
 }
 
-fn run(config: Config) {
+fn run(config: Config) -> Result<(), Box<dyn Error>> {
-    let contents = fs::read_to_string(config.file_path)
+    let contents = fs::read_to_string(config.file_path)?;
-        .expect("Should have been able to read the file");
-
     println!("With text:\n{contents}");
+    Ok(())
 }
 
 struct Config {