history : reexecution (issues #27 #28) - expansion !! !N !prefix ^old^new dans le REPL + am history --rerun N avec confirmation (shell ou commande am)

src/history.rs

@@ -124,6 +124,40 @@ pub fn migrate(app: &App) -> Result<usize> {
     Ok(count)
 }
 
+/// Expand a history reference against the most recent entries
+/// (most recent first): !! (last), !N (the Nth most recent), !prefix (the
+/// most recent command starting with prefix) and ^old^new (substitution in
+/// the last command). Returns None when the line is not a reference.
+pub fn expand(entries: &[HistoryEntry], line: &str) -> Option<String> {
+    let trimmed = line.trim();
+    if trimmed == "!!" {
+        return entries.first().map(|e| e.cmd.clone());
+    }
+    if let Some(rest) = trimmed.strip_prefix('!') {
+        if !rest.is_empty() {
+            if let Ok(n) = rest.parse::<usize>() {
+                if n >= 1 {
+                    return entries.get(n - 1).map(|e| e.cmd.clone());
+                }
+                return None;
+            }
+            return entries
+                .iter()
+                .find(|e| e.cmd.starts_with(rest))
+                .map(|e| e.cmd.clone());
+        }
+    }
+    if let Some(body) = trimmed.strip_prefix('^') {
+        if let Some((old, new)) = body.split_once('^') {
+            if !old.is_empty() {
+                let last = entries.first()?;
+                return Some(last.cmd.replacen(old, new, 1));
+            }
+        }
+    }
+    None
+}
+
 /// History files of a directory, oldest first.
 pub fn files(dir: &Path) -> Vec<PathBuf> {
     let mut out: Vec<PathBuf> = std::fs::read_dir(dir)
@@ -277,4 +311,22 @@ start group:dev
             Some("20260815_143926".to_string())
         );
     }
+
+    #[test]
+    fn expand_history_references() {
+        let entries = vec![
+            HistoryEntry::now("install jcode"),
+            HistoryEntry::now("start group:dev"),
+            HistoryEntry::now("list --all"),
+        ];
+        assert_eq!(expand(&entries, "!!").as_deref(), Some("install jcode"));
+        assert_eq!(expand(&entries, "!2").as_deref(), Some("start group:dev"));
+        assert_eq!(expand(&entries, "!9"), None, "out of range");
+        assert_eq!(expand(&entries, "!li").as_deref(), Some("list --all"));
+        assert_eq!(
+            expand(&entries, "^jcode^aider").as_deref(),
+            Some("install aider")
+        );
+        assert_eq!(expand(&entries, "plain line"), None);
+    }
 }