perf(wire): pre-size effect batch encoding

hemx-core/tests/effect_batch.rs

@@ -1,7 +1,8 @@
 use hemx_core::{
     event, navigate, redirect, replace, Atom, AtomSnapshot, AtomState, BuildFingerprint,
     ComponentRef, CssClass, CssClasses, Effect, EffectBatch, Form, Handle, IntoEffect, KeyedSlot,
-    NavigateMode, ParamName, Payload, ResourceKind, SafeHtml, ScopeKey, Slot,
+    NavigateMode, ParamName, Payload, ResourceId, ResourceKind, ResourceRef, SafeHtml, ScopeKey,
+    ScrollBehavior, Slot,
 };
 
 #[test]
@@ -22,12 +23,68 @@ fn effect_batch_wire_round_trips() {
 
     let bytes = batch.to_wire();
     assert_eq!(&bytes[..4], b"HEMX");
+    assert_eq!(batch.encoded_len(), bytes.len()); // req: wire/007
     let decoded = EffectBatch::from_wire(&bytes).unwrap();
 
     assert_eq!(decoded, batch);
     assert!(decoded.is_compatible());
 }
 
+#[test]
+fn encoded_len_covers_every_effect_shape() {
+    let unscoped = ResourceRef::unscoped(ResourceId::new(ResourceKind::Slot, 1));
+    let scoped = ResourceRef::scoped(
+        ResourceId::new(ResourceKind::Form, 2),
+        ScopeKey::Field(String::from("email")),
+    );
+    let batch = EffectBatch {
+        abi_version: hemx_core::EFFECT_BATCH_ABI_VERSION,
+        fingerprint: BuildFingerprint(42),
+        ops: vec![
+            Effect::Put {
+                target: unscoped.clone(),
+                payload: Payload::Html(String::from("<p>safe</p>")),
+            },
+            Effect::Insert {
+                target: scoped.clone(),
+                key: String::from("insert"),
+                payload: Payload::Text(String::from("one")),
+            },
+            Effect::Prepend {
+                target: scoped.clone(),
+                key: String::from("prepend"),
+                payload: Payload::Text(String::from("two")),
+            },
+            Effect::Remove {
+                target: scoped.clone(),
+                key: Some(String::from("remove")),
+            },
+            Effect::Move {
+                target: scoped.clone(),
+                key: String::from("move"),
+                before: Some(String::from("before")),
+            },
+            Effect::Focus {
+                target: scoped.clone(),
+            },
+            Effect::Navigate {
+                url: String::from("/next"),
+                mode: NavigateMode::Replace,
+                scroll: ScrollBehavior::Element(unscoped),
+                title: Some(String::from("Next")),
+            },
+            Effect::Emit {
+                name: String::from("notice"),
+                payload: String::from("saved"),
+            },
+        ],
+    };
+
+    let bytes = batch.to_wire();
+    assert_eq!(batch.encoded_len(), bytes.len()); // req: wire/007
+    assert_eq!(EffectBatch::from_wire(&bytes).unwrap(), batch);
+}
+
 #[test]
 fn optional_effects_compose_into_batches() {
     // req: component/005 req: public_api/003