Save history in localStorage.

src/lineengine/history.rs

@@ -1,5 +1,8 @@
 use std::collections::VecDeque;
 
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
 pub struct History {
     pub entries: VecDeque<String>,
     pub max_size: usize,

src/lineengine/line.rs

@@ -490,9 +490,20 @@ impl Write for WritetermFunction {
 
 impl Readline {
     pub fn new(prompt: String, write_fn: Box<dyn FnMut(&[u8])>, term_size: (u16, u16)) -> Self {
+        let mut line_state = LineState::new(prompt, term_size);
+        if let Some(existing_history) = web_sys::window().and_then(|w| {
+            w.local_storage()
+                .unwrap_or(None)
+                .and_then(|ls| ls.get("term_history").unwrap_or(None))
+        }) {
+            if let Ok(history) = serde_json::from_str(&existing_history) {
+                line_state.history = history;
+            }
+        }
+
         Self {
             term: TerminalState::new(),
-            line_state: LineState::new(prompt, term_size),
+            line_state,
             write_term: WritetermFunction { f: write_fn },
         }
     }
@@ -508,9 +519,21 @@ impl Readline {
     pub fn readline(&mut self, input: &[u8]) -> Result<Vec<ReadlineEvent>, ReadlineError> {
         let evs = self.term.events_for_input(input)?;
         let mut results: Vec<ReadlineEvent> = Vec::new();
+
         for ev in evs {
             results.extend(self.line_state.handle_event(ev, &mut self.write_term)?);
         }
+
+        if !results.is_empty() {
+            if let Ok(json) = serde_json::to_string(&self.line_state.history) {
+                web_sys::window().and_then(|w| {
+                    w.local_storage()
+                        .unwrap_or(None)
+                        .map(|ls| ls.set("term_history", &json))
+                });
+            }
+        }
+
         Ok(results)
     }
 }