test(cli): add unit and integration tests for applet dispatching

crates/irtt-cli/src/applet.rs

@@ -120,18 +120,58 @@ mod tests {
     }
 
     #[test]
-    fn default_applet_prefers_client_then_tui() {
+    fn canonical_help_renders_dispatcher_help() {
+        let dispatch = dispatch_from_argv(vec!["irtt-rs".into(), "--help".into()]).unwrap();
+        let AppletDispatch::Help(help) = dispatch else {
+            panic!("expected dispatcher help");
+        };
+        assert!(help.contains("IRTT-compatible multi-applet dispatcher"));
+        assert!(help.contains("client"));
+        assert!(help.contains("tui"));
+        assert!(help.contains("server"));
+    }
+
+    #[test]
+    fn canonical_without_applet_is_an_error() {
+        let err = dispatch_from_argv(vec!["irtt-rs".into()]).unwrap_err();
+        assert!(err.contains("choose an applet"));
+        assert!(err.contains("client"));
+        assert!(err.contains("tui"));
+        assert!(err.contains("server"));
+    }
+
+    #[test]
+    fn canonical_subcommands_dispatch_to_applet_argv() {
         assert_eq!(
-            default_applet_for_features(true, true, false),
-            AppletAvailability::Client
+            dispatch_from_argv(vec!["irtt-rs".into(), "client".into(), "host:2112".into()])
+                .unwrap(),
+            AppletDispatch::Run {
+                applet: RequestedApplet::Client,
+                argv: vec!["irtt-cli".into(), "host:2112".into()],
+            }
         );
         assert_eq!(
-            default_applet_for_features(false, true, false),
-            AppletAvailability::Tui
+            dispatch_from_argv(vec!["irtt-rs".into(), "tui".into(), "host:2112".into()]).unwrap(),
+            AppletDispatch::Run {
+                applet: RequestedApplet::Tui,
+                argv: vec!["irtt-tui".into(), "host:2112".into()],
+            }
         );
         assert_eq!(
-            default_applet_for_features(false, false, false),
-            AppletAvailability::None
+            dispatch_from_argv(vec!["irtt-rs".into(), "server".into()]).unwrap(),
+            AppletDispatch::Run {
+                applet: RequestedApplet::Server,
+                argv: vec!["irtt-server".into()],
+            }
         );
     }
+
+    #[test]
+    fn unknown_irtt_binary_name_is_an_error() {
+        let err = dispatch_from_argv(vec!["/usr/bin/irtt-typo".into()]).unwrap_err();
+        assert!(err.contains("unknown applet name 'irtt-typo'"));
+        assert!(err.contains("irtt-cli"));
+        assert!(err.contains("irtt-tui"));
+        assert!(err.contains("irtt-server"));
+    }
 }

crates/irtt-cli/tests/applet_dispatch.rs

@@ -0,0 +1,122 @@
+use std::process::{Command, Output};
+
+fn irtt_rs() -> Command {
+    Command::new(env!("CARGO_BIN_EXE_irtt-rs"))
+}
+
+#[cfg(unix)]
+fn irtt_rs_with_arg0(arg0: &str) -> Command {
+    use std::os::unix::process::CommandExt;
+
+    let mut command = irtt_rs();
+    command.arg0(arg0);
+    command
+}
+
+fn output_text(output: &Output) -> String {
+    let mut text = String::new();
+    text.push_str(&String::from_utf8_lossy(&output.stdout));
+    text.push_str(&String::from_utf8_lossy(&output.stderr));
+    text
+}
+
+#[test]
+fn canonical_help_shows_dispatcher_help() {
+    let output = irtt_rs().arg("--help").output().unwrap();
+    let text = output_text(&output);
+
+    assert!(output.status.success(), "{text}");
+    assert!(text.contains("IRTT-compatible multi-applet dispatcher"));
+    assert!(text.contains("client"));
+    assert!(text.contains("tui"));
+    assert!(text.contains("server"));
+}
+
+#[test]
+fn canonical_without_applet_errors() {
+    let output = irtt_rs().output().unwrap();
+    let text = output_text(&output);
+
+    assert!(!output.status.success());
+    assert!(text.contains("choose an applet"), "{text}");
+    assert!(text.contains("client"));
+    assert!(text.contains("tui"));
+    assert!(text.contains("server"));
+}
+
+#[test]
+fn canonical_client_subcommand_dispatches_to_client() {
+    let output = irtt_rs().args(["client", "--help"]).output().unwrap();
+    let text = output_text(&output);
+
+    assert!(output.status.success(), "{text}");
+    assert!(text.contains("Minimal IRTT-compatible stream client"));
+    assert!(text.contains("--output <OUTPUT>"));
+}
+
+#[cfg(unix)]
+#[test]
+fn client_applet_name_dispatches_to_client() {
+    let output = irtt_rs_with_arg0("irtt-cli")
+        .arg("--help")
+        .output()
+        .unwrap();
+    let text = output_text(&output);
+
+    assert!(output.status.success(), "{text}");
+    assert!(text.contains("Minimal IRTT-compatible stream client"));
+    assert!(text.contains("--output <OUTPUT>"));
+}
+
+#[cfg(all(unix, feature = "tui"))]
+#[test]
+fn tui_applet_name_dispatches_to_tui_when_enabled() {
+    let output = irtt_rs_with_arg0("irtt-tui")
+        .arg("--help")
+        .output()
+        .unwrap();
+    let text = output_text(&output);
+
+    assert!(output.status.success(), "{text}");
+    assert!(text.contains("Minimal IRTT-compatible TUI client"));
+    assert!(text.contains("--duration <DURATION>"));
+}
+
+#[cfg(all(unix, not(feature = "tui")))]
+#[test]
+fn tui_applet_name_reports_unavailable_when_disabled() {
+    let output = irtt_rs_with_arg0("irtt-tui")
+        .arg("--help")
+        .output()
+        .unwrap();
+    let text = output_text(&output);
+
+    assert!(!output.status.success());
+    assert!(text.contains("TUI applet is not available"), "{text}");
+}
+
+#[cfg(unix)]
+#[test]
+fn server_applet_name_reports_unavailable() {
+    let output = irtt_rs_with_arg0("irtt-server")
+        .arg("--help")
+        .output()
+        .unwrap();
+    let text = output_text(&output);
+
+    assert!(!output.status.success());
+    assert!(text.contains("server applet is not available"), "{text}");
+}
+
+#[cfg(unix)]
+#[test]
+fn unknown_irtt_applet_name_errors() {
+    let output = irtt_rs_with_arg0("irtt-typo").output().unwrap();
+    let text = output_text(&output);
+
+    assert!(!output.status.success());
+    assert!(text.contains("unknown applet name 'irtt-typo'"), "{text}");
+    assert!(text.contains("irtt-cli"));
+    assert!(text.contains("irtt-tui"));
+    assert!(text.contains("irtt-server"));
+}