Function del_char_end_tests

codegenr/src/helpers/string_ext.rs:248–255

(v: &str, trimmer: &str, expected: &str)

          Some(up) => {
            let c = if up {
              x.to_uppercase().next().unwrap_or(x)
            } else {
              x.to_lowercase().next().unwrap_or(x)
            };
            s.push(c);
          }
          None => s.push(x),
        }
        (None, s)
      });
    camel