• Binbin's avatar
    Fix misleading error message in XREADGROUP (#11799) · 312654d5
    Binbin authored
    XREADGROUP can output a misleading error message regarding use of the $ special ID.
    
    Here is the example (with some newlines):
    ```
    redis> xreadgroup group workers worker1 count 1 streams mystream
    (error) ERR Unbalanced XREAD list of streams: for each stream key an ID or '$' must be specified.
    
    redis> xreadgroup group workers worker1 count 1 streams mystream $
    (error) ERR The $ ID is meaningless in the context of XREADGROUP: you want to read the history of this
    consumer by specifying a proper ID, or use the > ID to get new messages. The $ ID would just return an empty result set.
    
    redis> xreadgroup group workers worker1 count 1 streams mystream >
    1) 1) "mystream"
       2) 1) 1) "1673544607848-0"
             2) 1) "n"
                2) "1"
    ```
    
    Note that XREADGROUP first returns an error with the following problems in it:
    - Command name in the error should be XREADGROUP not XREAD.
    - It recommends using $ as an option for a stream ID, then when y...
    312654d5
t_stream.c 157 KB