Add cli tests for skysh (#290)

cli/src/cli.rs

@@ -8,7 +8,7 @@ const HELP_TEMPLATE: &'static str = r#"
 {all-args}{after-help}
 "#;
 
-#[derive(Parser)]
+#[derive(Parser, Debug)]
 #[command(author, version, about, long_about=None, disable_help_flag=true, help_template=HELP_TEMPLATE)]
 pub struct Cli {
     #[arg(
@@ -43,3 +43,66 @@ pub struct Cli {
     #[arg(long, help="Print help information", action=ArgAction::Help)]
     pub help: Option<bool>,
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::cli::Cli;
+    use clap::error::ErrorKind;
+    use clap::Parser;
+
+    #[test]
+    fn test_no_user_args_picks_default_values() {
+        let args = vec!["skysh"];
+        let cli: Cli = Cli::parse_from(args.into_iter());
+        assert_eq!(cli.host, "127.0.0.1");
+        assert_eq!(cli.port, 2003);
+        assert_eq!(cli.expressions, None);
+        assert_eq!(cli.ssl_cert, None);
+    }
+
+    #[test]
+    fn test_invalid_arg_fails_validation() {
+        let args = vec!["skysh", "-p", "asd"];
+        let cli_result: Result<Cli, clap::Error> = Cli::try_parse_from(args.into_iter());
+
+        assert!(cli_result.is_err());
+        assert_eq!(cli_result.unwrap_err().kind(), ErrorKind::ValueValidation);
+
+        let args = vec!["skysh", "-h", "-1"];
+        let cli_result: Result<Cli, clap::Error> = Cli::try_parse_from(args.into_iter());
+
+        assert!(cli_result.is_err());
+        assert_eq!(cli_result.unwrap_err().kind(), ErrorKind::UnknownArgument);
+    }
+
+    #[test]
+    fn test_arg_override_works_as_expected() {
+        let args = vec![
+            "skysh",
+            "-p",
+            "666",
+            "-h",
+            "devil",
+            "--sslcert",
+            "/tmp/mycert.pem",
+            "-e",
+            "SET X 100",
+            "GET X",
+            "UPDATE X 42",
+        ];
+        let cli: Cli = Cli::parse_from(args.into_iter());
+
+        assert_eq!(cli.host, "devil");
+        assert_eq!(cli.port, 666);
+        assert_eq!(cli.ssl_cert, Some("/tmp/mycert.pem".into()));
+        assert_eq!(
+            cli.expressions,
+            Some(vec![
+                "SET X 100".into(),
+                "GET X".into(),
+                "UPDATE X 42".into()
+            ])
+        )
+    }
+
+}