replace null separator in apq cache key with : to match convention (#…

…4886)

This PR conforms the apq cache key to follow redis convention. This
helps when using redis clients to properly display keys in nested form.

query plan cache key was fixed in a similar pr:
#4583

Co-authored-by: Geoffroy Couprie <geo.couprie@gmail.com>

.changesets/fix_apq_cache_key_to_match_redis_convention.md

@@ -0,0 +1,7 @@
+### Replaces null separator in apq cache key with : to match redis convention
+
+This PR conforms the apq cache key to follow redis convention. This helps when using redis clients to properly display keys in nested form.
+
+query plan cache key was fixed in a similar pr: #4583
+
+By [@tapaderster](https://github.com/tapaderster) in https://github.com/apollographql/router/pull/4886

apollo-router/src/services/layers/apq.rs

@@ -158,7 +158,7 @@ fn query_matches_hash(query: &str, hash: &[u8]) -> bool {
 }
 
 fn redis_key(query_hash: &str) -> String {
-    format!("apq\0{query_hash}")
+    format!("apq:{query_hash}")
 }
 
 pub(crate) fn calculate_hash_for_query(query: &str) -> String {

apollo-router/tests/integration/redis.rs

@@ -165,7 +165,7 @@ mod test {
         let query_hash = "4c45433039407593557f8a982dafd316a66ec03f0e1ed5fa1b7ef8060d76e8ec";
 
         client
-            .del::<String, _>(&format!("apq\x00{query_hash}"))
+            .del::<String, _>(&format!("apq:{query_hash}"))
             .await
             .unwrap();
 
@@ -196,8 +196,7 @@ mod test {
             res.errors.first().unwrap().message,
             "PersistedQueryNotFound"
         );
-
-        let r: Option<String> = client.get(&format!("apq\x00{query_hash}")).await.unwrap();
+        let r: Option<String> = client.get(&format!("apq:{query_hash}")).await.unwrap();
         assert!(r.is_none());
 
         // Now we register the query
@@ -222,7 +221,7 @@ mod test {
         assert!(res.data.is_some());
         assert!(res.errors.is_empty());
 
-        let s: Option<String> = client.get(&format!("apq\x00{query_hash}")).await.unwrap();
+        let s: Option<String> = client.get(&format!("apq:{query_hash}")).await.unwrap();
         insta::assert_display_snapshot!(s.unwrap());
 
         // we start a new router with the same config