From 1cf0d9f89f4141417b6b522dbb38dd9a9ee1654a Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonyg@leastfixedpoint.com>
Date: Wed, 3 Mar 2021 11:48:07 +0100
Subject: [PATCH] Less ceremony around proxied retractions

---
 src/actor.ts     | 19 +++++++++----------
 src/dataspace.ts |  7 ++-----
 2 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/src/actor.ts b/src/actor.ts
index 78172fe..a449c39 100644
--- a/src/actor.ts
+++ b/src/actor.ts
@@ -209,15 +209,17 @@ export class Turn {
         }
     }
 
-    retract(h: Handle): void {
-        const peer = this.actor.outbound.get(h);
-        if (peer === void 0) return;
-        this._retract(peer, h);
+    retract(h: Handle | undefined): void {
+        if (h !== void 0) {
+            const peer = this.actor.outbound.get(h);
+            if (peer === void 0) return;
+            this._retract(peer, h);
+        }
     }
 
     replace(ref: Ref, h: Handle | undefined, assertion: Assertion): Handle {
         const newHandle = this.assert(ref, assertion);
-        if (h !== void 0) this.retract(h);
+        this.retract(h);
         return newHandle;
     }
 
@@ -411,11 +413,8 @@ export function forwarder(t: Turn, ref: Ref): { proxy: Ref, revoker: Ref } {
         },
         retract(turn: Turn, handle: Handle): void {
             if (underlying === null) return;
-            const h = handleMap.get(handle);
-            if (h !== void 0) {
-                turn.retract(h);
-                handleMap.delete(handle);
-            }
+            turn.retract(handleMap.get(handle));
+            handleMap.delete(handle);
         },
         message(turn: Turn, body: Assertion): void {
             if (underlying === null) return;
diff --git a/src/dataspace.ts b/src/dataspace.ts
index a74ea6a..f4c4026 100644
--- a/src/dataspace.ts
+++ b/src/dataspace.ts
@@ -61,11 +61,8 @@ export class Dataspace implements Partial<Entity> {
         this.handleMap.delete(upstreamHandle);
         if (this.assertions.change(rec, -1) !== ChangeDescription.PRESENT_TO_ABSENT) return;
         this.subscriptions.get(rec.label)?.forEach((seen, _peer) => {
-            const downstreamHandle = seen.get(rec);
-            if (downstreamHandle !== void 0) {
-                turn.retract(downstreamHandle);
-                seen.delete(rec);
-            }
+            turn.retract(seen.get(rec));
+            seen.delete(rec);
         });
         if (Observe.isClassOf(rec)) {
             let peerMap = this.subscriptions.get(Observe._.label(rec)!)!;