feat: report support for read_group in capabilities request (#586)

src/server/rpc/service.rs

@@ -332,8 +332,6 @@ where
             InternalHintsFieldNotSupported { hints }.fail()?
         }
 
-        warn!("read_group implementation not yet complete: https://github.com/influxdata/influxdb_iox/issues/448");
-
         let aggregate_string = format!(
             "aggregate: {:?}, group: {:?}, group_keys: {:?}",
             aggregate, group, group_keys
@@ -569,7 +567,8 @@ where
         //
 
         // For now, hard code our list of support
-        let caps = [(
+        let caps = [
+            (
                 "WindowAggregate",
                 vec![
                     "Count", "Sum", // "First"
@@ -577,7 +576,9 @@ where
                     "Min", "Max", "Mean",
                     // "Offset"
                 ],
-        )];
+            ),
+            ("Group", vec!["First", "Last", "Min", "Max"]),
+        ];
 
         // Turn it into the HashMap -> Capabiltity
         let caps = caps
@@ -1241,6 +1242,8 @@ mod tests {
             to_str_vec(&["Count", "Sum", "Min", "Max", "Mean"]),
         );
 
+        expected_capabilities.insert("Group".into(), to_str_vec(&["First", "Last", "Min", "Max"]));
+
         assert_eq!(
             expected_capabilities,
             fixture.storage_client.capabilities().await?

tests/end-to-end.rs

@@ -203,7 +203,7 @@ async fn read_and_write_data() -> Result<()> {
     let capabilities_response = capabilities_response.into_inner();
     assert_eq!(
         capabilities_response.caps.len(),
-        1,
+        2,
         "Response: {:?}",
         capabilities_response
     );