Adding error handling to read file methds

filesort-rs/.vscode/launch.json

@@ -19,7 +19,7 @@
                     "kind": "bin"
                 }
             },
-            "args": ["--input-file","test.txt","--output-file","out.txt"],
+            "args": ["--input-file","foo.txt","--output-file","out.txt"],
             "cwd": "${workspaceFolder}"
         },
         {

filesort-rs/out.txt

@@ -1,10 +0,0 @@
-1
-2
-3
-4
-44
-5
-6
-7
-8
-9

filesort-rs/src/file_sort.rs

@@ -1,5 +1,7 @@
+use std::io::Error;
+
 pub trait FileSort {
-    fn read(&mut self);
+    fn read(&mut self) -> Result<bool,Error>;
     fn write(&mut self);
     fn sort(&mut self);
 }

filesort-rs/src/line_sort.rs

@@ -1,7 +1,7 @@
 use crate::file_sort::FileSort;
 
 use std::fs::File;
-use std::io::{BufRead, BufReader, Write};
+use std::io::{BufRead, BufReader, Write, Error};
 
 pub struct LineSort {
     lines: Vec<String>,
@@ -22,8 +22,8 @@ impl LineSort {
 }
 
 impl FileSort for LineSort {
-    fn read(&mut self) {
-        let file = File::open(&self.input_file).expect("input file doesn't exist");
+    fn read(&mut self) -> Result<bool,Error> {
+        let file = File::open(&self.input_file)?;
 
         let buffer: BufReader<File> = BufReader::new(file);
 
@@ -34,6 +34,8 @@ impl FileSort for LineSort {
                 self.lines.push(new_line);
             }
         }
+
+        return Ok(true);
     }
 
     fn write(&mut self) {

filesort-rs/src/main.rs

@@ -16,9 +16,18 @@ fn main() {
             let mut linesort: LineSort = LineSort::new(args.input_file, args.output_file, args.descending);
 
             println!("Filesort start\n");
-            println!("Reading file data\n");
+            println!("Reading file data (by Line)\n");
 
-            linesort.read();
+            let result = linesort.read();
+
+            match result {
+                Ok(_res) => { 
+                },
+                Err(e) => { 
+                    eprintln!("An error occured with the input file\n{}", e);
+                    return;
+                }
+            }
 
             println!("Soritng data\n");
 
@@ -33,8 +42,29 @@ fn main() {
     else {
         let mut wordsort: WordSort = WordSort::new(args.input_file, args.output_file, args.descending);
 
-        wordsort.read();
+        println!("Filesort start\n");
+        println!("Reading file data (by Word)\n");
+
+        let result = wordsort.read();
+
+        match result {
+            Ok(_res) => { 
+            },
+            Err(e) => { 
+                eprintln!("An error occured with the input file\n{}", e);
+                return;
+            }
+        }
+
+        println!("Soritng data\n");
+
         wordsort.sort();
+
+        println!("Writing file data\n");
+
         wordsort.write();
+
+        println!("Filesort complete\n");
+
     }
 }

filesort-rs/src/word_sort.rs

@@ -1,7 +1,7 @@
 use crate::file_sort::FileSort;
 
 use std::fs::File;
-use std::io::{BufRead, BufReader, Write};
+use std::io::{BufRead, BufReader, Write, Error};
 
 pub struct WordSort {
     lines: Vec<String>,
@@ -22,14 +22,16 @@ impl WordSort {
 }
 
 impl FileSort for WordSort {
-    fn read(&mut self) {
-        let file = File::open(&self.input_file).expect("input file doesn't exist");
+    fn read(&mut self) -> Result<bool,Error> {
+        let file = File::open(&self.input_file)?;
 
         let buffer: BufReader<File> = BufReader::new(file);
 
         for line in buffer.lines() {
             self.lines.push(line.unwrap_or_default());
         }
+
+        return Ok(true);
     }
 
     fn write(&mut self) {