feat: implement proper cli exit codes

src/main.rs

@@ -1,4 +1,8 @@
+use std::process::ExitCode;
+
 use clap::Parser;
+
+use crate::matches::Matches;
 mod matches;
 mod parser;
 
@@ -8,16 +12,25 @@ struct Cli {
     file_path: String,
 }
 
-fn main() -> anyhow::Result<()> {
+fn main() -> ExitCode {
+    match run() {
+        Ok(matches) if matches.is_empty() == true => ExitCode::FAILURE,
+        Ok(matches) => {
+            println!("{}", matches);
+            ExitCode::SUCCESS
+        }
+        Err(error) => {
+            eprintln!("{}", error);
+            ExitCode::from(2)
+        }
+    }
+}
+
+fn run() -> anyhow::Result<Matches> {
     let cli = Cli::parse();
 
     let lines_iter = parser::read_lines(&cli.file_path)?;
-    let matches = parser::match_pattern(lines_iter, &cli.pattern, &cli.file_path);
+    let matches = parser::match_pattern(lines_iter, &cli.pattern, &cli.file_path)?;
 
-    println!("Pattern: {}", cli.pattern);
-    println!("File path: {}", cli.file_path);
-    println!("---");
-    println!("{}", matches?);
-
-    Ok(())
+    Ok(matches)
 }

src/matches.rs

@@ -11,6 +11,12 @@ pub struct Matches {
     pub pattern: String,
 }
 
+impl Matches {
+    pub fn is_empty(&self) -> bool {
+        self.items.is_empty()
+    }
+}
+
 impl Display for Match {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "{}: line {}: {}", self.file_name, self.line_number, self.text)

test.txt

@@ -1,2 +1,4 @@
 hola
 no
+hola again
+yep it's me