Split linkDown() into canCarry() and droppedWhileDraining()

src/outgoing-requests.ts

@@ -51,9 +51,14 @@ export class OutgoingRequests {
 		this.window = new SendWindow({ limit: options.maxOutstanding, log: options.log });
 	}
 
-	/** Read through a method: a drop can land while a request is awaiting. */
-	linkDown(): boolean {
-		return !this.gate.isUp() || this.transport.sock.destroyed;
+	/** Whether a request made now reaches the socket. Read through a method: a drop can land while one awaits. */
+	canCarry(): boolean {
+		return this.gate.isUp() && !this.transport.sock.destroyed;
+	}
+
+	/** The link went while draining, so the teardown settled what the drain waited on, not the peer. */
+	droppedWhileDraining(): boolean {
+		return this.draining && !this.canCarry();
 	}
 
 	/** A link is up and bound, so everything held for one goes out on it. */
@@ -84,8 +89,8 @@ export class OutgoingRequests {
 
 		if (wrong) return Promise.resolve({ err: wrong });
 
-		// A drain on a live link. A link that is down is the gate's answer, which says closed instead.
-		if (this.draining && !this.linkDown()) {
+		// With no link, the gate answers instead, and says closed.
+		if (this.draining && this.canCarry()) {
 			return Promise.resolve({ err: new Error('Session is shutting down') });
 		}
 

src/session.ts

@@ -333,7 +333,8 @@ export class Session extends EventEmitter<SessionEvents> {
 		this.reconnectLoop?.stop();
 		this.outgoing.stopAccepting();
 
-		if (this.outgoing.linkDown()) return {};
+		// No link, so nothing is on the wire to wait out.
+		if (!this.outgoing.canCarry()) return {};
 
 		const timeout = this.options.shutdownTimeout ?? defaults.shutdownTimeout;
 		const deadline = timeout > 0 ? Date.now() + timeout : 0;
@@ -341,8 +342,7 @@ export class Session extends EventEmitter<SessionEvents> {
 		const messages = await this.incoming.drain(this.answering(timeout), signal);
 		const requests = await this.outgoing.drain(leftOf(deadline), signal);
 
-		// The window empties on a teardown too, which settles everything the link was carrying.
-		if (this.outgoing.linkDown()) {
+		if (this.outgoing.droppedWhileDraining()) {
 			return { err: new Error('The session closed before the drain finished') };
 		}