pixi-demo/tests/chase/chaseGenerator.test.ts

import { describe, expect, it } from "vitest";
import { shortestPathLength } from "../../src/game/chase/hexGraph";
import { generateChaseRound } from "../../src/game/chase/generator";
import type { Difficulty } from "../../src/game/chase/types";

describe("chase round generator", () => {
  it("is deterministic for same seed and difficulty", () => {
    const options = { seed: 20260426, difficulty: "normal" as Difficulty };
    const roundA = generateChaseRound(options);
    const roundB = generateChaseRound(options);

    expect(roundA).toEqual(roundB);
  });

  it("matches golden snapshot for fixed seed", () => {
    const round = generateChaseRound({ seed: 424242, difficulty: "easy" });

    expect({
      startNodeId: round.startNodeId,
      exitNodeId: round.exitNodeId,
      hasEscapePath: round.meta.hasEscapePath,
      nodeCount: Object.keys(round.graph.nodes).length,
      edgeCount: round.graph.edgeList.length,
      firstFiveNodeIds: Object.keys(round.graph.nodes).slice(0, 5),
    }).toMatchInlineSnapshot(`
      {
        "edgeCount": 19,
        "exitNodeId": "0,-1",
        "firstFiveNodeIds": [
          "0,0",
          "1,-1",
          "2,-2",
          "2,-1",
          "1,-2",
        ],
        "hasEscapePath": true,
        "nodeCount": 20,
        "startNodeId": "4,-5",
      }
    `);
  });

  it("generates graph node count between 20 and 30", () => {
    const round = generateChaseRound({ seed: 11, difficulty: "normal" });
    const nodeCount = Object.keys(round.graph.nodes).length;
    expect(nodeCount).toBeGreaterThanOrEqual(20);
    expect(nodeCount).toBeLessThanOrEqual(30);
  });

  it("ensures an escape path exists", () => {
    const round = generateChaseRound({ seed: 99, difficulty: "hard" });
    const pathLength = shortestPathLength(
      round.graph,
      round.startNodeId,
      round.exitNodeId,
    );

    expect(round.meta.hasEscapePath).toBe(true);
    expect(pathLength).toBeGreaterThan(0);
    expect(pathLength).toBeLessThan(Infinity);
  });
});