Add first unit test

src/main.rs

@@ -6,16 +6,18 @@ use totp_rfc6238::{HashAlgorithm, TotpGenerator};
 
 /// Get the current time since epoch
 pub fn time() -> u64 {
-    SystemTime::now().duration_since(UNIX_EPOCH).unwrap().as_secs()
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap()
+        .as_secs()
 }
 
-
 /// TOTP - One Time Password generator
 #[derive(Parser, Debug)]
 #[clap(author, version, about, long_about = None)]
 struct Args {
     #[clap(subcommand)]
-    command: SubCommands
+    command: SubCommands,
 }
 
 #[derive(Subcommand, Debug)]
@@ -48,24 +50,34 @@ fn main() {
             println!("To configure TOPT :");
             println!("1. Please open https://mysignins.microsoft.com/security-info");
             println!("2. Click on \"Add method\"");
-            println!("3. On the popup that appears, choose \"Authenticator app\" and click \"Add\".");
-            println!("4. Click on \"I want to use a different authenticator app\" and click \"Next\"");
+            println!(
+                "3. On the popup that appears, choose \"Authenticator app\" and click \"Add\"."
+            );
+            println!(
+                "4. Click on \"I want to use a different authenticator app\" and click \"Next\""
+            );
             println!("5. Click on \"Can't save image ?\" and copy the \"Secret key\"");
-            println!("6. Re-run this program running {} code --secret <SECRET>", std::env::args().next().unwrap());
+            println!(
+                "6. Re-run this program running {} code --secret <SECRET>",
+                std::env::args().next().unwrap()
+            );
             println!("7. Back on the browser, click Next and paste copied code");
         }
 
-        SubCommands::Code { secret, topt_step, len } => {
+        SubCommands::Code {
+            secret,
+            topt_step,
+            len,
+        } => {
             let totp_generator = TotpGenerator::new()
-                .set_digit(len).unwrap()
-                .set_step(topt_step).unwrap()
+                .set_digit(len)
+                .unwrap()
+                .set_step(topt_step)
+                .unwrap()
                 .set_hash_algorithm(HashAlgorithm::SHA1)
                 .build();
 
-            let key = base32::decode(
-                Alphabet::RFC4648 { padding: true },
-                &secret,
-            ).unwrap();
+            let key = base32::decode(Alphabet::RFC4648 { padding: true }, &secret).unwrap();
 
             let code = totp_generator.get_code(&key);
             let next_update = totp_generator.get_next_update_time().unwrap();
@@ -75,3 +87,14 @@ fn main() {
         }
     }
 }
+
+#[cfg(test)]
+mod test {
+    use crate::Args;
+
+    #[test]
+    fn verify_cli() {
+        use clap::CommandFactory;
+        Args::command().debug_assert()
+    }
+}