import { GraphNode, topologicalSort } from "./graph";

describe("lib/util/graph", () => {
	describe("topologicalSort()", () => {
		it("should sort correctly (Test 1)", () => {
			const nodes = [
				new GraphNode(1),
				new GraphNode(2),
				new GraphNode(3),
				new GraphNode(4),
			];
			nodes[0].edges.add(nodes[1]);
			nodes[0].edges.add(nodes[2]);
			nodes[1].edges.add(nodes[3]);
			nodes[2].edges.add(nodes[3]);

			expect(topologicalSort(nodes)).toEqual([4, 2, 3, 1]);
		});

		it("should sort correctly (Test 2)", () => {
			const nodes = [
				new GraphNode(1),
				new GraphNode(2),
				new GraphNode(3),
				new GraphNode(4),
			];
			nodes[0].edges.add(nodes[3]);
			nodes[0].edges.add(nodes[2]);
			nodes[3].edges.add(nodes[1]);
			nodes[2].edges.add(nodes[3]);

			expect(topologicalSort(nodes)).toEqual([2, 4, 3, 1]);
		});

		it("should throw when there are circular dependencies", () => {
			const nodes = [
				new GraphNode(1),
				new GraphNode(2),
				new GraphNode(3),
				new GraphNode(4),
			];
			nodes[0].edges.add(nodes[1]);
			nodes[1].edges.add(nodes[3]);
			nodes[3].edges.add(nodes[2]);
			nodes[2].edges.add(nodes[0]);

			expect(() => topologicalSort(nodes)).toThrow();
		});
	});
});