feat: Add shortest paths placeholder function

Author: Sirivasv

src/bmssp.mjs

@@ -4,22 +4,36 @@ class BMSSP {
     this.graph = [];
     // Set to store unique node IDs
     this.nodeIDs = new Set();
-    // Array to store shortest paths
-    this.shortestPaths = [];
+    // Map to store shortest paths
+    this.shortestPaths = new Map();
 
     for (let edge of inputGraph) {
       // Create a deep copy of each edge array
       this.graph.push([...edge]);
+
       // Add node IDs to the set
       this.nodeIDs.add(edge[0]);
       this.nodeIDs.add(edge[1]);
     }
 
-    // Initialize shortest paths with Infinity on each nodeID (after all nodes are collected)
+    // Initialize shortest paths map
+    this.initializeShortestPaths();
+  }
+
+  // Method to initialize the shortest paths map
+  initializeShortestPaths() {
     for (let nodeId of this.nodeIDs) {
-      this.shortestPaths.push([nodeId, Infinity]);
+      this.shortestPaths.set(nodeId, Infinity);
     }
   }
+
+  // Method to calculate shortest paths (placeholder implementation)
+  calculateShortestPaths(startNode) {
+    // Placeholder logic for shortest path calculation
+    // This should be replaced with an actual implementation of BMSSP algorithm
+    this.initializeShortestPaths();
+    this.shortestPaths.set(startNode, 0);
+  }
 }
 
 export { BMSSP };

test/main.test.mjs

@@ -41,10 +41,19 @@ describe("BMSSP nodeIDs", () => {
 describe("BMSSP shortestPaths", () => {
   test("initializes shortest paths with Infinity", () => {
     const myBMSSP = new BMSSP(roadNetCA);
-    const expectedShortestPaths = [];
+    const expectedShortestPaths = new Map();
     myBMSSP.nodeIDs.forEach((nodeId) => {
-      expectedShortestPaths.push([nodeId, Infinity]);
+      expectedShortestPaths.set(nodeId, Infinity);
     });
     expect(myBMSSP.shortestPaths).toEqual(expectedShortestPaths);
   });
 });
+
+describe("BMSSP initialize calculateShortestPaths", () => {
+  test("sets the distance to the start node to 0", () => {
+    const myBMSSP = new BMSSP(roadNetCA);
+    const startNode = [...myBMSSP.nodeIDs][0];
+    myBMSSP.calculateShortestPaths(startNode);
+    expect(myBMSSP.shortestPaths.get(startNode)).toBe(0);
+  });
+});