fix: apparently there's a bug for the length of the map

Author: tyrchen

src/respv2/mod.rs

@@ -145,19 +145,32 @@ mod tests {
 
     #[test]
     fn respv2_map_length_should_work() {
-        let buf = b"%2\r\n+OK\r\n-ERR\r\n";
+        let buf = b"%1\r\n+OK\r\n-ERR\r\n";
         let len = RespFrame::expect_length(buf).unwrap();
         assert_eq!(len, buf.len());
     }
 
     #[test]
     fn respv2_map_should_work() {
-        let mut buf = BytesMut::from("%2\r\n+OK\r\n-ERR\r\n");
+        let mut buf = BytesMut::from("%1\r\n+OK\r\n-ERR\r\n");
         let frame = RespFrame::decode(&mut buf).unwrap();
         let items: BTreeMap<String, RespFrame> =
             [("OK".to_string(), RespFrame::Error("ERR".into()))]
                 .into_iter()
                 .collect();
         assert_eq!(frame, RespFrame::Map(items.into()));
     }
+
+    #[test]
+    fn respv2_map_with_real_data_should_work() {
+        let mut buf = BytesMut::from("%2\r\n+hello\r\n$5\r\nworld\r\n+foo\r\n$3\r\nbar\r\n");
+        let frame = RespFrame::decode(&mut buf).unwrap();
+        let items: BTreeMap<String, RespFrame> = [
+            ("hello".to_string(), RespFrame::BulkString("world".into())),
+            ("foo".to_string(), RespFrame::BulkString("bar".into())),
+        ]
+        .into_iter()
+        .collect();
+        assert_eq!(frame, RespFrame::Map(items.into()));
+    }
 }

src/respv2/parser.rs

@@ -167,13 +167,13 @@ fn double(input: &mut &[u8]) -> PResult<f64> {
     terminated(float, CRLF).parse_next(input)
 }
 
-// - map: "%2\r\n+foo\r\n-bar\r\n"
+// my understanding of map len is incorrect: https://redis.io/docs/latest/develop/reference/protocol-spec/#maps
+// - map: "%1\r\n+foo\r\n-bar\r\n"
 fn map(input: &mut &[u8]) -> PResult<RespMap> {
     let len: i64 = integer.parse_next(input)?;
     if len <= 0 {
         return Err(err_cut("map length must be non-negative"));
     }
-    let len = len as usize / 2;
     let mut map = BTreeMap::new();
     for _ in 0..len {
         let key = preceded('+', parse_string).parse_next(input)?;
@@ -188,7 +188,6 @@ fn map_len(input: &mut &[u8]) -> PResult<()> {
     if len <= 0 {
         return Err(err_cut("map length must be non-negative"));
     }
-    let len = len as usize / 2;
     for _ in 0..len {
         terminated(take_until(0.., CRLF), CRLF)
             .value(())