fix: getRemoteNodeClosestNodes shouldn't throw connection errors

`getRemoteNodeClosestNodes` was throwing an connection error in certain conditions. If it failed to connect to a node it should've just skipped that node.

#418

src/nodes/NodeConnectionManager.ts

@@ -26,8 +26,6 @@ import * as nodesErrors from './errors';
 import GRPCClientAgent from '../agent/GRPCClientAgent';
 import * as validationUtils from '../validation/utils';
 import * as networkUtils from '../network/utils';
-import * as agentErrors from '../agent/errors';
-import * as grpcErrors from '../grpc/errors';
 import * as nodesPB from '../proto/js/polykey/v1/nodes/nodes_pb';
 import { timerStart } from '../utils';
 
@@ -190,11 +188,7 @@ class NodeConnectionManager {
       return [
         async (e) => {
           await release();
-          if (
-            e instanceof nodesErrors.ErrorNodeConnectionDestroyed ||
-            e instanceof grpcErrors.ErrorGRPC ||
-            e instanceof agentErrors.ErrorAgentClientDestroyed
-          ) {
+          if (nodesUtils.isConnectionError(e)) {
             // Error with connection, shutting connection down
             await this.destroyConnection(targetNodeId);
           }
@@ -467,9 +461,6 @@ class NodeConnectionManager {
     // Let foundTarget: boolean = false;
     let foundAddress: NodeAddress | undefined = undefined;
     // Get the closest alpha nodes to the target node (set as shortlist)
-    // FIXME? this is an array. Shouldn't it be a set?
-    //  It's possible for this to grow faster than we can consume it,
-    //  doubly so if we allow duplicates
     const shortlist = await this.nodeGraph.getClosestNodes(
       targetNodeId,
       this.initialClosestNodes,
@@ -487,7 +478,7 @@ class NodeConnectionManager {
     const contacted: { [nodeId: string]: boolean } = {};
     // Iterate until we've found and contacted k nodes
     while (Object.keys(contacted).length <= this.nodeGraph.nodeBucketLimit) {
-      if (signal?.aborted) throw new nodesErrors.ErrorNodeAborted();
+      if (signal?.aborted) throw signal.reason;
       // While (!foundTarget) {
       // Remove the node from the front of the array
       const nextNode = shortlist.shift();
@@ -522,6 +513,7 @@ class NodeConnectionManager {
         targetNodeId,
         timer,
       );
+      if (foundClosest.length === 0) continue;
       // Check to see if any of these are the target node. At the same time, add
       // them to the shortlist
       for (const [nodeId, nodeData] of foundClosest) {
@@ -585,36 +577,43 @@ class NodeConnectionManager {
     // Construct the message
     const nodeIdMessage = new nodesPB.Node();
     nodeIdMessage.setNodeId(nodesUtils.encodeNodeId(targetNodeId));
-    // Send through client
-    return this.withConnF(
-      nodeId,
-      async (connection) => {
-        const client = connection.getClient();
-        const response = await client.nodesClosestLocalNodesGet(nodeIdMessage);
-        const nodes: Array<[NodeId, NodeData]> = [];
-        // Loop over each map element (from the returned response) and populate nodes
-        response.getNodeTableMap().forEach((address, nodeIdString: string) => {
-          const nodeId = nodesUtils.decodeNodeId(nodeIdString);
-          // If the nodeId is not valid we don't add it to the list of nodes
-          if (nodeId != null) {
-            nodes.push([
-              nodeId,
-              {
-                address: {
-                  host: address.getHost() as Host | Hostname,
-                  port: address.getPort() as Port,
-                },
-                // Not really needed
-                // But if it's needed then we need to add the information to the proto definition
-                lastUpdated: 0,
+    try {
+      // Send through client
+      const response = await this.withConnF(
+        nodeId,
+        async (connection) => {
+          const client = connection.getClient();
+          return await client.nodesClosestLocalNodesGet(nodeIdMessage);
+        },
+        timer,
+      );
+      const nodes: Array<[NodeId, NodeData]> = [];
+      // Loop over each map element (from the returned response) and populate nodes
+      response.getNodeTableMap().forEach((address, nodeIdString: string) => {
+        const nodeId = nodesUtils.decodeNodeId(nodeIdString);
+        // If the nodeId is not valid we don't add it to the list of nodes
+        if (nodeId != null) {
+          nodes.push([
+            nodeId,
+            {
+              address: {
+                host: address.getHost() as Host | Hostname,
+                port: address.getPort() as Port,
               },
-            ]);
-          }
-        });
-        return nodes;
-      },
-      timer,
-    );
+              // Not really needed
+              // But if it's needed then we need to add the information to the proto definition
+              lastUpdated: 0,
+            },
+          ]);
+        }
+      });
+      return nodes;
+    } catch (e) {
+      if (nodesUtils.isConnectionError(e)) {
+        return [];
+      }
+      throw e;
+    }
   }
 
   /**

src/nodes/utils.ts

@@ -8,8 +8,11 @@ import type { KeyPath } from '@matrixai/db';
 import { IdInternal } from '@matrixai/id';
 import lexi from 'lexicographic-integer';
 import { utils as dbUtils } from '@matrixai/db';
+import * as nodesErrors from './errors';
 import { bytes2BigInt } from '../utils';
 import * as keysUtils from '../keys/utils';
+import * as grpcErrors from '../grpc/errors';
+import * as agentErrors from '../agent/errors';
 
 const sepBuffer = dbUtils.sep;
 
@@ -310,6 +313,14 @@ function generateRandomNodeIdForBucket(
   return xOrNodeId(nodeId, randomDistanceForBucket);
 }
 
+function isConnectionError(e): boolean {
+  return (
+    e instanceof nodesErrors.ErrorNodeConnectionDestroyed ||
+    e instanceof grpcErrors.ErrorGRPC ||
+    e instanceof agentErrors.ErrorAgentClientDestroyed
+  );
+}
+
 export {
   sepBuffer,
   encodeNodeId,
@@ -330,4 +341,5 @@ export {
   generateRandomDistanceForBucket,
   xOrNodeId,
   generateRandomNodeIdForBucket,
+  isConnectionError,
 };