perf(graph): optimize BFS in findConnectedGraph

lib/common/graph.js

@@ -106,32 +106,25 @@ class DirectedGraph {
             sourceVertices = [sourceVertices];
         }
 
-        // Track our descent
-        const visited = {};
+        const visited = new Set(sourceVertices);
         const queue = [...sourceVertices];
 
-        // Initialize the state
-        sourceVertices.forEach(v => { visited[v] = true; });
-
-        // Perform a BFS search of the graph.
-        let currentVertex;
-        while (queue.length > 0) {
-            currentVertex = queue[0];
-            queue.shift();
-
-            const edges = this.adjacencyMap[currentVertex] || [];
-
-            edges.forEach(edge => {
-                if (!visited[edge]) {
-                    visited[edge] = true;
-                    queue.push(edge);
+        // BFS using an index pointer
+        for (let i = 0; i < queue.length; i++) {
+            const edges = this.adjacencyMap[queue[i]];
+            if (edges) {
+                for (let j = 0; j < edges.length; j++) {
+                    if (!visited.has(edges[j])) {
+                        visited.add(edges[j]);
+                        queue.push(edges[j]);
+                    }
                 }
-            });
+            }
         }
 
         return new DirectedGraph(Object.fromEntries(
             Object.entries(this.adjacencyMap)
-                .filter(([vertex]) => visited[vertex])
+                .filter(([vertex]) => visited.has(vertex))
         ));
     }