Add more tests and fixes

src/convert.rs

@@ -62,8 +62,8 @@ pub fn convert_to_mltt(
     for key in combinators {
         if let Some(value) = map.get(&key) {
             while let Some(index) = text_to_convert.find(&key) {
-                let middle_char = get_prev_char(&text_to_convert, index);
-                let mid_val = map.get(&format!("{}", middle_char)).unwrap();
+                let middle_char = get_prev_char(&text_to_convert, index).to_string();
+                let mid_val = map.get(&middle_char).unwrap_or(&middle_char);
                 let split_val = value.split("").collect::<Vec<_>>();
                 let new_key = format!("{}{}", middle_char, key);
                 let new_val = format!("{}{}{}", split_val[1], mid_val, split_val[2]);

tests/convertion.rs

@@ -88,6 +88,38 @@ fn convert_case_short_8() -> Result<(), Box<dyn Error>> {
     )
 }
 
+#[test]
+fn convert_case_short_9() -> Result<(), Box<dyn Error>> {
+    test_convertion(
+        r#"പൊടുന്നനെ"#, 
+        r#"s]mSp¶s\"#
+    )
+}
+
+#[test]
+fn convert_case_short_10() -> Result<(), Box<dyn Error>> {
+    test_convertion(
+        r#"കിളികൊല്ലൂർ"#, 
+        r#"InfnsImÃqÀ"#
+    )
+}
+
+#[test]
+fn convert_case_short_11() -> Result<(), Box<dyn Error>> {
+    test_convertion(
+        r#"കോയമ്പത്തൂർ"#, 
+        r#"tImb¼¯qÀ"#
+    )
+}
+
+#[test]
+fn convert_case_short_12() -> Result<(), Box<dyn Error>> {
+    test_convertion(
+        r#"മുക്കോലയ്ക്കൽ"#, 
+        r#"apt¡mebv¡Â"#
+    )
+}
+
 #[test]
 fn convert_case_long_1() -> Result<(), Box<dyn Error>> {
     test_convertion(