Add first tests

Cargo.toml

@@ -6,3 +6,5 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+clap = { version = "3.1.6", features = ["derive"]  }
+regex = { version = "*" }

src/main.rs

@@ -1,3 +1,16 @@
-fn main() {
-    println!("Hello, world!");
+use clap::Parser;
+
+/// Simple program to greet a person
+#[derive(Parser, Debug)]
+#[clap(author, version, about, long_about = None)]
+struct Arguments {
+    #[clap(short, long, default_value = ".carman")]
+    conf_file: String,
+}
+
+fn main() {
+    let args = Arguments::parse();
+
+    println!("Hello, world!");
+    println!("{:?}", args);
 }

tests/integration.rs

@@ -1,8 +1,9 @@
 // filename: tests/integration.rs
 
-
 mod integration {
+    use regex::Regex;
     use std::process::Command;
+    use std::process::Output;
 
     static WITHOUT_ARGS_OUTPUT: &'static str = " USAGE:
         carman [FLAGS] [OPTIONS] <URL>
@@ -10,12 +11,24 @@ mod integration {
     ";
 
     #[test]
-    fn calling_carman_without_args() {
+    fn calling_carman_without_args_returns_result() {
         let  output = Command::new("./target/debug/carman")
             .output()
             .expect("failed to execute process");
+        let re = Regex::new(r"^Hello").unwrap();
+        assert!(re.is_match(&String::from_utf8_lossy(&output.stdout)));
+    }
 
-        assert_eq!(String::from_utf8_lossy(&output.stderr), WITHOUT_ARGS_OUTPUT);
+    #[test]
+    fn calling_carman_with_help_returns_usage() {
+        let  output = Command::new("./target/debug/carman")
+            .arg("--help")
+            .output()
+            .expect("failed to execute process");
+        let re = Regex::new(r"^carman").unwrap();
+        assert!(re.is_match(&String::from_utf8_lossy(&output.stdout)));
+        let re = Regex::new(r"--help").unwrap();
+        assert!(re.is_match(&String::from_utf8_lossy(&output.stdout)));
     }
     
 }