feat: solution for 'Повторный экзамен #2: Граф с рефлексией на код'

__tests__/graph.test.js

@@ -0,0 +1,53 @@
+// __tests__/graph.test.js
+import { Graph } from '../src/graph.js';
+
+describe('Graph', () => {
+  let g;
+
+  beforeEach(() => {
+    g = new Graph();
+    g.addNode('1', { label: 'One' });
+    g.addNode('2', { label: 'Two' });
+    g.addNode('3', { label: 'Three' });
+  });
+
+  test('adds nodes correctly', () => {
+    expect(g.nodes.size).toBe(3);
+    expect(g.nodes.get('1').label).toBe('One');
+  });
+
+  test('adds edges correctly', () => {
+    g.addEdge('1', '2');
+    g.addEdge('2', '3');
+    expect(g.neighbors('1')).toEqual(['2']);
+    expect(g.neighbors('2')).toEqual(['3']);
+    expect(g.neighbors('3')).toEqual([]);
+  });
+
+  test('throws error when adding edge with non-existent node', () => {
+    expect(() => g.addEdge('1', '4')).toThrow();
+  });
+
+  test('adds reflexive edges', () => {
+    g.addReflexiveEdges();
+    expect(g.neighbors('1')).toContain('1');
+    expect(g.neighbors('2')).toContain('2');
+    expect(g.neighbors('3')).toContain('3');
+  });
+
+  test('toJSON returns correct structure', () => {
+    g.addEdge('1', '2');
+    const json = g.toJSON();
+    expect(json.nodes).toHaveLength(3);
+    expect(json.edges).toHaveLength(1);
+    expect(json.edges[0]).toEqual({ src: '1', dst: '2' });
+  });
+
+  test('fromJSON recreates graph', () => {
+    g.addEdge('1', '2');
+    const json = g.toJSON();
+    const g2 = Graph.fromJSON(json);
+    expect(g2.nodes.size).toBe(3);
+    expect(g2.neighbors('1')).toEqual(['2']);
+  });
+});