consider change to Context::upsert()

[garypen]

Currently, upsert() takes a parameter to specify a default value. It might be more complex than we need. We could simply specify that values inserted via upsert() are Default.

I checked and this wouldn't break any code in the current router codebase.

What do people think? Good idea or leave things alone?

% git diff
diff --git a/apollo-router-core/src/context.rs b/apollo-router-core/src/context.rs
index a185439b..5bde2825 100644
--- a/apollo-router-core/src/context.rs
+++ b/apollo-router-core/src/context.rs
@@ -60,16 +60,16 @@ impl Context {
         &self,
         key: K,
         upsert: impl Fn(V) -> V,
-        default: impl Fn() -> V,
+        // default: impl Fn() -> V,
     ) -> Result<(), BoxError>
     where
         K: Into<String>,
-        V: for<'de> serde::Deserialize<'de> + Serialize,
+        V: for<'de> serde::Deserialize<'de> + Serialize + Default,
     {
         let key = key.into();
         self.entries
             .entry(key.clone())
-            .or_try_insert_with(|| serde_json_bytes::to_value((default)()))?;
+            .or_try_insert_with(|| serde_json_bytes::to_value::<V>(Default::default()))?;
         let mut result = Ok(());
         self.entries
             .alter(&key, |_, v| match serde_json_bytes::from_value(v.clone()) {

[garypen]

Locking discussion as this change has been made. See: #1070 and #1073.