feat(irtt-cli): note running-only continuous summaries

crates/irtt-cli/src/main.rs

@@ -77,6 +77,7 @@ fn run(args: CliArgs, shutdown_requested: &AtomicBool) -> Result<(), Box<dyn std
             verbose: args.verbose,
         },
         print_final_summary: false,
+        show_running_only_summary_note: false,
         out: &mut stdout,
         #[cfg(feature = "stats")]
         stats: &mut stats,
@@ -130,7 +131,9 @@ fn run(args: CliArgs, shutdown_requested: &AtomicBool) -> Result<(), Box<dyn std
 
     let events = client.close()?;
     output.print_events(&events)?;
-    output.print_final_summary = should_print_final_summary(continuous, interrupted);
+    let print_final_summary = should_print_final_summary(continuous, interrupted);
+    output.print_final_summary = print_final_summary;
+    output.show_running_only_summary_note = continuous && interrupted && print_final_summary;
     output.print_summary()?;
     output.out.flush()?;
     Ok(())
@@ -210,6 +213,7 @@ struct EventOutput<'a, W: Write> {
     mode: irtt_cli::OutputMode,
     human_options: HumanOutputOptions,
     print_final_summary: bool,
+    show_running_only_summary_note: bool,
     out: &'a mut W,
     #[cfg(feature = "stats")]
     stats: &'a mut StatsCollector,
@@ -261,6 +265,7 @@ impl<W: Write> EventOutput<'_, W> {
                     &self.stats.snapshot(),
                     irtt_cli::summary::SummaryFormatOptions {
                         verbose: self.human_options.verbose,
+                        show_running_only_note: self.show_running_only_summary_note,
                     },
                 )
             )?;
@@ -471,6 +476,7 @@ mod tests {
                 mode: irtt_cli::OutputMode::RttUs,
                 human_options: HumanOutputOptions::default(),
                 print_final_summary: true,
+                show_running_only_summary_note: false,
                 out: &mut out,
                 stats: &mut stats,
             };
@@ -494,6 +500,7 @@ mod tests {
                 mode: irtt_cli::OutputMode::Human,
                 human_options: HumanOutputOptions::default(),
                 print_final_summary: false,
+                show_running_only_summary_note: true,
                 out: &mut out,
                 stats: &mut stats,
             };
@@ -512,6 +519,7 @@ mod tests {
                 mode: irtt_cli::OutputMode::Human,
                 human_options: HumanOutputOptions::default(),
                 print_final_summary: true,
+                show_running_only_summary_note: true,
                 out: &mut out,
                 stats: &mut stats,
             };
@@ -521,6 +529,8 @@ mod tests {
 
         let rendered = String::from_utf8(out).unwrap();
         assert!(rendered.contains("irtt-rs summary"));
+        assert!(rendered.contains("medians unavailable"));
+        assert!(rendered.contains("continuous mode"));
         assert!(rendered.contains("packets:"));
         assert!(rendered.contains("received=1"));
     }
@@ -535,6 +545,7 @@ mod tests {
                 mode: irtt_cli::OutputMode::Human,
                 human_options: HumanOutputOptions::default(),
                 print_final_summary: false,
+                show_running_only_summary_note: false,
                 out: &mut out,
                 stats: &mut stats,
             };

crates/irtt-cli/src/summary.rs

@@ -9,6 +9,7 @@ pub fn format_summary(summary: &Snapshot) -> String {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
 pub struct SummaryFormatOptions {
     pub verbose: bool,
+    pub show_running_only_note: bool,
 }
 
 pub fn format_summary_with_options(summary: &Snapshot, options: SummaryFormatOptions) -> String {
@@ -18,6 +19,13 @@ pub fn format_summary_with_options(summary: &Snapshot, options: SummaryFormatOpt
 
     writeln!(out).unwrap();
     writeln!(out, "irtt-rs summary").unwrap();
+    if options.show_running_only_note {
+        writeln!(
+            out,
+            "note: medians unavailable in continuous mode; running statistics are bounded-memory"
+        )
+        .unwrap();
+    }
     writeln!(out).unwrap();
     writeln!(
         out,
@@ -232,6 +240,7 @@ mod tests {
         assert!(output.contains("10.0µs"));
         assert!(output.contains("timer error"));
         assert!(output.contains("2.0µs"));
+        assert!(!output.contains("medians unavailable"));
     }
 
     #[test]
@@ -259,13 +268,32 @@ mod tests {
 
         let output = format_summary_with_options(
             &collector.snapshot(),
-            SummaryFormatOptions { verbose: true },
+            SummaryFormatOptions {
+                verbose: true,
+                ..SummaryFormatOptions::default()
+            },
         );
 
         assert!(output.contains("raw RTT"));
         assert!(output.contains("adjusted RTT"));
     }
 
+    #[test]
+    fn running_only_note_is_format_option() {
+        let summary = StatsCollector::new(StatsConfig::continuous()).snapshot();
+        let output = format_summary_with_options(
+            &summary,
+            SummaryFormatOptions {
+                show_running_only_note: true,
+                ..SummaryFormatOptions::default()
+            },
+        );
+
+        assert!(output.contains("irtt-rs summary"));
+        assert!(output.contains("medians unavailable"));
+        assert!(output.contains("continuous mode"));
+    }
+
     #[test]
     fn signed_stats_can_format_negative_values() {
         let stats = TimeStats {