From 6b964179608211f4fa300ffe4f1885055654123d Mon Sep 17 00:00:00 2001
From: Michael Davis <mcarsondavis@gmail.com>
Date: Tue, 2 Jan 2024 16:48:31 -0500
Subject: [PATCH] Normalize `S-<lower-ascii>` keymaps to uppercase ascii

Keymaps that use the shift modifier and a lowercase ascii character
should be equivalent to keymaps that use just the uppercase of that
ascii character. We can normalize key events as we parse them out of
strings so that both representations parse to the same event. This
allows mapping keys like `C-S-r` which previously could only be bound
by `C-R`.
---
 helix-view/src/input.rs | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/helix-view/src/input.rs b/helix-view/src/input.rs
index 0f4ffaacf9cc..5f5067eac9f8 100644
--- a/helix-view/src/input.rs
+++ b/helix-view/src/input.rs
@@ -325,7 +325,7 @@ impl std::str::FromStr for KeyEvent {
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         let mut tokens: Vec<_> = s.split('-').collect();
-        let code = match tokens.pop().ok_or_else(|| anyhow!("Missing key code"))? {
+        let mut code = match tokens.pop().ok_or_else(|| anyhow!("Missing key code"))? {
             keys::BACKSPACE => KeyCode::Backspace,
             keys::ENTER => KeyCode::Enter,
             keys::LEFT => KeyCode::Left,
@@ -405,6 +405,18 @@ impl std::str::FromStr for KeyEvent {
             modifiers.insert(flag);
         }
 
+        // Normalize character keys so that characters like C-S-r and C-R
+        // are represented by equal KeyEvents.
+        match code {
+            KeyCode::Char(ch)
+                if ch.is_ascii_lowercase() && modifiers.contains(KeyModifiers::SHIFT) =>
+            {
+                code = KeyCode::Char(ch.to_ascii_uppercase());
+                modifiers.remove(KeyModifiers::SHIFT);
+            }
+            _ => (),
+        }
+
         Ok(KeyEvent { code, modifiers })
     }
 }
@@ -684,6 +696,19 @@ mod test {
                 modifiers: KeyModifiers::ALT | KeyModifiers::CONTROL
             }
         );
+
+        assert_eq!(
+            str::parse::<KeyEvent>("C-S-r").unwrap(),
+            str::parse::<KeyEvent>("C-R").unwrap(),
+        );
+
+        assert_eq!(
+            str::parse::<KeyEvent>("S-w").unwrap(),
+            KeyEvent {
+                code: KeyCode::Char('W'),
+                modifiers: KeyModifiers::NONE
+            }
+        );
     }
 
     #[test]