Improve unit test for str

src/str.rs

@@ -58,10 +58,23 @@ pub fn unescape(s: &str) -> Vec<u8> {
 }
 
 #[test]
-fn test_unescape() {
+fn escape_unescape() {
     let s = "\\000";
     let unescaped = unescape(s);
     let escaped = escape(&unescaped);
     assert_eq!(escaped, "\\000");
     assert_eq!(unescaped[0], 0);
+    // short string
+    let s = "\\00";
+    let unescaped = unescape(s);
+    let escaped = escape(&unescaped);
+    assert_eq!(escaped, "\\00");
+    assert_eq!(unescaped[0], 0);
+    // string containing upper and lower case hex
+    let s = "\\A0a";
+    let unescaped = unescape(s);
+    let escaped = escape(&unescaped);
+    assert_eq!(escaped, "\\a0a");
+    assert_eq!(unescaped[0], 160); // A0
+    assert_eq!(unescaped[1], 97); // A
 }