Bugfix: Missing CPR arguments causes panic (#39)

- Added `CSI::Invalid` and return that if CPR is missing arguments No
- No need for `CSI::new()` to return `Option` as `None` value is never
  created.
- Added test

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- Bugfix: Missing CPR arguments causes panic
+
 ## [0.5.0 - 2024-12-12]
 
 - Removed initializer. Probe terminal size before prompt for every line.

noline/src/core.rs

@@ -353,6 +353,7 @@ where
                 CSI::DSR => self.generate_output(RingBell),
                 CSI::SU(_) => self.generate_output(RingBell),
                 CSI::SD(_) => self.generate_output(RingBell),
+                CSI::Invalid => self.generate_output(RingBell),
             },
             Action::EscapeSequence(_) => self.generate_output(RingBell),
             Action::Ignore => self.generate_output(Nothing),

noline/src/input.rs

@@ -67,20 +67,27 @@ pub enum CSI {
     Delete,
     End,
     Unknown(u8),
+    Invalid,
 }
 
 impl CSI {
-    fn new(byte: u8, arg1: Option<usize>, arg2: Option<usize>) -> Option<Self> {
+    fn new(byte: u8, arg1: Option<usize>, arg2: Option<usize>) -> Self {
         let c = byte as char;
 
-        Some(match c {
+        match c {
             'A' => Self::CUU(arg1.unwrap_or(1)),
             'B' => Self::CUD(arg1.unwrap_or(1)),
             'C' => Self::CUF(arg1.unwrap_or(1)),
             'D' => Self::CUB(arg1.unwrap_or(1)),
             'H' => Self::CUP(arg1.unwrap_or(1), arg2.unwrap_or(1)),
             'J' => Self::ED(arg1.unwrap_or(0)),
-            'R' => Self::CPR(arg1.unwrap(), arg2.unwrap()),
+            'R' => {
+                if let (Some(arg1), Some(arg2)) = (arg1, arg2) {
+                    Self::CPR(arg1, arg2)
+                } else {
+                    Self::Invalid
+                }
+            }
             'S' => Self::SU(arg1.unwrap_or(1)),
             'T' => Self::SD(arg1.unwrap_or(1)),
             'n' => Self::DSR,
@@ -97,7 +104,7 @@ impl CSI {
                 }
             }
             _ => Self::Unknown(byte),
-        })
+        }
     }
 }
 
@@ -122,7 +129,7 @@ impl Action {
     }
 
     fn csi(byte: u8, arg1: Option<usize>, arg2: Option<usize>) -> Self {
-        Action::ControlSequenceIntroducer(CSI::new(byte, arg1, arg2).unwrap())
+        Action::ControlSequenceIntroducer(CSI::new(byte, arg1, arg2))
     }
 }
 
@@ -283,6 +290,24 @@ pub(crate) mod tests {
             assert_eq!(action, Action::Ignore);
         }
 
+        let mut actions = input_sequence(&mut parser, "\x1b[R");
+        assert_eq!(
+            actions.pop().unwrap(),
+            Action::ControlSequenceIntroducer(CSI::Invalid)
+        );
+
+        let mut actions = input_sequence(&mut parser, "\x1b[32R");
+        assert_eq!(
+            actions.pop().unwrap(),
+            Action::ControlSequenceIntroducer(CSI::Invalid)
+        );
+
+        let mut actions = input_sequence(&mut parser, "\x1b[32;R");
+        assert_eq!(
+            actions.pop().unwrap(),
+            Action::ControlSequenceIntroducer(CSI::Invalid)
+        );
+
         let mut actions = input_sequence(&mut parser, "\x1b[A");
 
         assert_eq!(

noline/src/testlib.rs

@@ -152,6 +152,7 @@ impl MockTerminal {
                 CSI::Home => unimplemented!(),
                 CSI::Delete => unimplemented!(),
                 CSI::End => unimplemented!(),
+                CSI::Invalid => unimplemented!(),
             },
             Action::InvalidUtf8 => unreachable!(),
             Action::ControlCharacter(ctrl) => {