Add case propagation also with prefix symbol. Fix #244

src/matcher/mod.rs

@@ -92,7 +92,14 @@ impl<'a> From<&'a AutoMatch> for Match{
             let first_capitalized : Vec<String> = triggers.iter().map(|trigger| {
                 let capitalized = trigger.clone();
                 let mut v: Vec<char> = capitalized.chars().collect();
-                v[0] = v[0].to_uppercase().nth(0).unwrap();
+
+                // Capitalize the first alphabetic letter
+                // See issue #244
+                let first_alphabetic = v.iter().position(|c| {
+                    c.is_alphabetic()
+                }).unwrap_or(0);
+
+                v[first_alphabetic] = v[first_alphabetic].to_uppercase().nth(0).unwrap();
                 v.into_iter().collect()
             }).collect();
 
@@ -482,4 +489,30 @@ mod tests {
 
         let _match : Match = serde_yaml::from_str(match_str).unwrap();
     }
+
+    #[test]
+    fn test_match_propagate_case_with_prefix_symbol() {
+        let match_str = r###"
+        trigger: ":hello"
+        replace: "This is a test"
+        propagate_case: true
+        "###;
+
+        let _match : Match = serde_yaml::from_str(match_str).unwrap();
+
+        assert_eq!(_match.triggers, vec![":hello", ":Hello", ":HELLO"])
+    }
+
+    #[test]
+    fn test_match_propagate_case_non_alphabetic_should_not_crash() {
+        let match_str = r###"
+        trigger: ":.."
+        replace: "This is a test"
+        propagate_case: true
+        "###;
+
+        let _match : Match = serde_yaml::from_str(match_str).unwrap();
+
+        assert_eq!(_match.triggers, vec![":..", ":..", ":.."])
+    }
 }

src/render/default.rs

@@ -173,8 +173,16 @@ impl super::Renderer for DefaultRenderer {
                 // Handle case propagation
                 let target_string = if m.propagate_case {
                     let trigger = &m.triggers[trigger_offset];
-                    let first_char = trigger.chars().nth(0);
-                    let second_char  = trigger.chars().nth(1);
+
+                    // The check should be carried out from the position of the first
+                    // alphabetic letter
+                    // See issue #244
+                    let first_alphabetic = trigger.chars().position(|c| {
+                        c.is_alphabetic()
+                    }).unwrap_or(0);
+
+                    let first_char = trigger.chars().nth(first_alphabetic);
+                    let second_char  = trigger.chars().nth(first_alphabetic + 1);
                     let mode: i32 = if let Some(first_char) = first_char {
                         if first_char.is_uppercase() {
                             if let Some(second_char) = second_char {