feat(sync): add typed acknowledgement effect

req: sync/006

hemx-sync/src/lib.rs

@@ -1,4 +1,4 @@
-use hemx_core::{Effect, EffectBatch, IntoEffect};
+use hemx_core::{Atom, Effect, EffectBatch, IntoEffect};
 use serde::{de, Deserialize, Deserializer, Serialize};
 use std::{
     collections::{HashMap, HashSet},
@@ -12,6 +12,7 @@ pub use hemx_sync_macros::presence;
 
 pub const PATCH_SCHEMA_VERSION: u16 = 1;
 pub const PATCH_EVENT: &str = "hemx:sync-patch";
+pub const ACK_EVENT: &str = "hemx:sync-ack";
 const INTERACTION_ID: &str = "$hemx-interaction";
 pub const BROWSER_RUNTIME: &str = include_str!("../runtime/hemx-sync.js");
 
@@ -387,7 +388,7 @@ fn validate_key(key: &str) -> Result<(), PatchError> {
 }
 
 #[derive(Clone, Debug, Eq, PartialEq)]
-pub struct SyncEffect(Effect); // req: sync/002
+pub struct SyncEffect(Vec<Effect>); // req: sync/002
 
 impl SyncEffect {
     // req: sync/004
@@ -398,18 +399,29 @@ impl SyncEffect {
         }
     }
 
+    // req: sync/006
+    pub fn ack<T>(atom: Atom<T>) -> Self {
+        Self(vec![
+            atom.set("acknowledged"),
+            Effect::Emit {
+                name: ACK_EVENT.to_owned(),
+                payload: format!(r#"{{"atomId":{}}}"#, atom.id().id),
+            },
+        ])
+    }
+
     pub fn send_patch(patch: FlatPatch) -> Self {
         patch.validate().expect("FlatPatch must remain valid");
-        Self(Effect::Emit {
+        Self(vec![Effect::Emit {
             name: PATCH_EVENT.to_owned(),
             payload: patch.payload(),
-        })
+        }])
     }
 }
 
 impl IntoEffect for SyncEffect {
     fn append_to(self, ops: &mut Vec<Effect>) {
-        self.0.append_to(ops);
+        ops.extend(self.0);
     }
 }
 
@@ -417,6 +429,18 @@ impl IntoEffect for SyncEffect {
 mod tests {
     use super::*;
 
+    #[test]
+    fn acknowledgement_updates_atom_and_emits_queue_signal() {
+        let atom = Atom::<String>::new(17);
+        let batch = SyncEffect::ack(atom).into_batch(hemx_core::BuildFingerprint(3));
+        assert!(
+            matches!(&batch.ops[0], Effect::Put { target, payload: hemx_core::Payload::Text(payload) } if target.resource == atom.id() && payload == "acknowledged")
+        );
+        assert!(
+            matches!(&batch.ops[1], Effect::Emit { name, payload } if name == ACK_EVENT && payload == r#"{"atomId":17}"#)
+        );
+    }
+
     #[test]
     fn presence_macro_projects_an_ordinary_effect_on_its_channel() {
         struct Signal(Channel);