feat: open selected YouTube video in browser

src/youtube.rs

@@ -805,6 +805,52 @@ fn failure(errors: &Receiver<io::Result<String>>, fallback: String) -> Option<Re
     }
 }
 
+pub fn open_in_browser(id: &str) -> io::Result<Receiver<Result<(), String>>> {
+    if !valid_video_id(id) {
+        return Err(io::Error::new(
+            io::ErrorKind::InvalidInput,
+            "Invalid YouTube video ID",
+        ));
+    }
+    let opener = if cfg!(target_os = "macos") {
+        "open"
+    } else {
+        "xdg-open"
+    };
+    let child = isolated_command(OsStr::new(opener))
+        .arg(format!("https://www.youtube.com/watch?v={id}"))
+        .stdin(Stdio::null())
+        .stdout(Stdio::null())
+        .stderr(Stdio::piped())
+        .spawn()
+        .map_err(|error| {
+            io::Error::new(
+                error.kind(),
+                format!("Cannot start browser opener: {error}"),
+            )
+        })?;
+    let (sender, receiver) = mpsc::channel();
+    thread::spawn(move || {
+        let result = child
+            .wait_with_output()
+            .map_err(|error| format!("Cannot wait for browser opener: {error}"))
+            .and_then(|output| {
+                if output.status.success() {
+                    Ok(())
+                } else {
+                    let error = String::from_utf8_lossy(&output.stderr);
+                    Err(format!(
+                        "Browser opener exited with {}: {}",
+                        output.status,
+                        error.trim()
+                    ))
+                }
+            });
+        let _ = sender.send(result);
+    });
+    Ok(receiver)
+}
+
 pub struct PlayerLaunch {
     player: Child,
     player_errors: Receiver<io::Result<String>>,
@@ -1465,6 +1511,16 @@ mod tests {
         }
     }
 
+    #[test]
+    fn browser_open_rejects_unsafe_video_ids_before_spawning() {
+        for id in ["", "--help", "jNQXAC9IVRw&list=other", "日本語"] {
+            assert!(matches!(
+                open_in_browser(id),
+                Err(error) if error.kind() == io::ErrorKind::InvalidInput
+            ));
+        }
+    }
+
     #[test]
     fn publication_dates_prefer_exact_metadata_and_handle_utc_boundaries_and_invalid_dates() {
         for feed in [false, true] {