nEngine/packages/render/test/sync-local.test.ts

import { mkdtemp, mkdir, rm, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { describe, expect, it } from "vitest";
import { createEngine } from "@nengine/core";
import { connectLocal } from "../src/sync/local.js";
import type { RenderSnapshot, ViewportHandle } from "../src/viewport.js";

const TIME_YAML = [
  "id: default",
  "dayLengthTicks: 480",
  "seasons:",
  "  - { name: spring, dayCount: 28 }",
  "start: { day: 1, season: spring }",
  "",
].join("\n");

const FARM_YAML = [
  "id: farm",
  "width: 5",
  "height: 5",
  'tilesetRef: "tiles"',
  "spawn: { x: 0, y: 0 }",
  "layers:",
  "  - name: ground",
  "    data:",
  "      - [grass, grass, water, water, water]",
  "      - [grass, grass, water, water, water]",
  "      - [grass, grass, grass, grass, grass]",
  "      - [grass, grass, grass, grass, grass]",
  "      - [grass, grass, grass, grass, grass]",
  "",
].join("\n");

function fakeViewport(): { viewport: ViewportHandle; renders: RenderSnapshot[] } {
  const renders: RenderSnapshot[] = [];
  const viewport: ViewportHandle = {
    render(snapshot?: RenderSnapshot): void {
      if (snapshot) renders.push(snapshot);
    },
    tileAt(): { x: number; y: number } | null {
      return null;
    },
    resize(): void {},
    destroy(): void {},
  };
  return { viewport, renders };
}

interface Setup {
  engine: ReturnType<typeof createEngine>;
  close: () => Promise<void>;
}

async function setup(): Promise<Setup> {
  const tmp = await mkdtemp(join(tmpdir(), "farm-sync-local-"));
  await mkdir(join(tmp, "maps"), { recursive: true });
  await writeFile(join(tmp, "time.yaml"), TIME_YAML);
  await writeFile(join(tmp, "maps", "farm.yaml"), FARM_YAML);
  const engine = createEngine({ contentDir: tmp });
  await engine.start();
  return {
    engine,
    close: async () => {
      await engine.stop();
      await rm(tmp, { recursive: true, force: true });
    },
  };
}

describe("connectLocal sync handle", () => {
  it("renders a full snapshot (map + world entities) on connect", async () => {
    const { engine, close } = await setup();
    try {
      const { viewport, renders } = fakeViewport();
      connectLocal(engine, viewport);
      expect(renders).toHaveLength(1);
      expect(renders[0].map).toMatchObject({ id: "farm", width: 5, height: 5 });
      const ids = renders[0].world.map((entity) => entity.id);
      expect(ids).toContain("player");
    } finally {
      await close();
    }
  });

  it("intent() delegates to the engine IntentSystem and re-renders the viewport", async () => {
    const { engine, close } = await setup();
    try {
      const { viewport, renders } = fakeViewport();
      const sync = connectLocal(engine, viewport);
      const before = renders.length;

      sync.intent("move", { tile: { x: 3, y: 3 } });
      expect(engine.world.get("player")).toMatchObject({ x: 3, y: 3 });
      expect(renders.length).toBeGreaterThan(before);

      const last = renders[renders.length - 1];
      const player = last.world.find((entity) => entity.id === "player") as { x?: number; y?: number } | undefined;
      expect(player).toMatchObject({ x: 3, y: 3 });
    } finally {
      await close();
    }
  });

  it("setTimeLabel reports the current time state", async () => {
    const { engine, close } = await setup();
    try {
      const { viewport } = fakeViewport();
      const sync = connectLocal(engine, viewport);
      const labels: string[] = [];
      sync.setTimeLabel((label) => labels.push(label));
      expect(labels[labels.length - 1]).toBe("Day 1, spring");
    } finally {
      await close();
    }
  });

  it("input() maps key:Arrow* to a move intent one tile from the player", async () => {
    const { engine, close } = await setup();
    try {
      const { viewport, renders } = fakeViewport();
      const sync = connectLocal(engine, viewport);
      const before = renders.length;

      sync.input("key:ArrowDown");
      expect(engine.world.get("player")).toMatchObject({ x: 0, y: 1 });
      expect(renders.length).toBeGreaterThan(before);

      sync.input("key:ArrowRight");
      expect(engine.world.get("player")).toMatchObject({ x: 1, y: 1 });
    } finally {
      await close();
    }
  });

  it("input() ignores non-arrow inputs", async () => {
    const { engine, close } = await setup();
    try {
      const { viewport } = fakeViewport();
      const sync = connectLocal(engine, viewport);
      sync.input("key:Space");
      sync.input("pointer:click:1:2");
      expect(engine.world.get("player")).toMatchObject({ x: 0, y: 0 });
    } finally {
      await close();
    }
  });

  it("intent() passes the extended actions through (select-seed sets player.selectedSeed)", async () => {
    const { engine, close } = await setup();
    try {
      engine.registry.register("item", { id: "parsnip-seed", name: "Parsnip Seed", kind: "seed", stackable: true });
      const { viewport, renders } = fakeViewport();
      const sync = connectLocal(engine, viewport);
      const before = renders.length;

      sync.intent("select-seed", { seedItemId: "parsnip-seed" });
      expect(engine.world.get("player")).toMatchObject({ selectedSeed: "parsnip-seed" });
      expect(renders.length).toBeGreaterThan(before);

      sync.intent("buy", { shopId: "nope", itemId: "parsnip-seed" });
      expect(renders.length).toBeGreaterThan(before);
    } finally {
      await close();
    }
  });
});