Method breadthFirstTraverse

src/data/Graph.ts:218–261

* Breadth first traverse * Return true to stop traversing

(
        cb: (this: Ctx, node: GraphNode, fromNode: GraphNode) => boolean | void,
        startNode: GraphNode | string,
        direction: 'none' | 'in' | 'out',
        context?: Ctx
    )

     * Return true to stop traversing
     */
    breadthFirstTraverse<Ctx>(
        cb: (this: Ctx, node: GraphNode, fromNode: GraphNode) => boolean | void,
        startNode: GraphNode | string,
        direction: 'none' | 'in' | 'out',
        context?: Ctx
    ) {
        if (!(startNode instanceof GraphNode)) {
            startNode = this._nodesMap[generateNodeKey(startNode)];
        }
        if (!startNode) {
            return;
        }

        const edgeType: 'inEdges' | 'outEdges' | 'edges' = direction === 'out'
            ? 'outEdges' : (direction === 'in' ? 'inEdges' : 'edges');

        for (let i = 0; i < this.nodes.length; i++) {
            this.nodes[i].__visited = false;
        }

        if (cb.call(context, startNode, null)) {
            return;
        }

        const queue = [startNode];
        while (queue.length) {
            const currentNode = queue.shift();
            const edges = currentNode[edgeType];

            for (let i = 0; i < edges.length; i++) {
                const e = edges[i];
                const otherNode = e.node1 === currentNode
                    ? e.node2 : e.node1;
                if (!otherNode.__visited) {
                    if (cb.call(context, otherNode, currentNode)) {
                        // Stop traversing
                        return;
                    }
                    queue.push(otherNode);
                    otherNode.__visited = true;
                }
            }
        }
    };

    // TODO
    // depthFirstTraverse(