nEngine/apps/editor/test/playtest-session.test.ts

import { describe, expect, it } from "vitest";
import { createPlaytestSession, keydownInput, saveAllFlushes } from "../src/renderer/playtest-session.js";

describe("saveAllFlushes", () => {
  it("writes clean flushes and reports them as flushed", async () => {
    const written: string[] = [];
    const result = await saveAllFlushes(
      [
        { path: "a.yaml", content: "x" },
        { path: "b.yaml", content: "y" },
      ],
      async (path, content) => {
        written.push(`${path}:${content}`);
      },
    );
    expect(result.flushed).toEqual(["a.yaml", "b.yaml"]);
    expect(result.failures).toEqual([]);
    expect(written).toEqual(["a.yaml:x", "b.yaml:y"]);
  });

  it("records error flushes and rejecting writes as failures without throwing", async () => {
    const result = await saveAllFlushes(
      [
        { path: "bad.yaml", error: "map invalid" },
        { path: "throws.yaml", content: "z" },
        { path: "ok.yaml", content: "ok" },
      ],
      async (path) => {
        if (path === "throws.yaml") throw new Error("disk full");
      },
    );
    expect(result.flushed).toEqual(["ok.yaml"]);
    expect(result.failures).toEqual([
      { path: "bad.yaml", error: "map invalid" },
      { path: "throws.yaml", error: "disk full" },
    ]);
  });

  it("writes nothing when there are no flushes", async () => {
    const result = await saveAllFlushes([], async () => {
      throw new Error("unreachable");
    });
    expect(result.flushed).toEqual([]);
    expect(result.failures).toEqual([]);
  });
});

describe("keydownInput", () => {
  it("maps arrow keys to raw inputs", () => {
    expect(keydownInput("ArrowUp")).toBe("key:ArrowUp");
    expect(keydownInput("ArrowDown")).toBe("key:ArrowDown");
    expect(keydownInput("ArrowLeft")).toBe("key:ArrowLeft");
    expect(keydownInput("ArrowRight")).toBe("key:ArrowRight");
  });

  it("returns undefined for non-arrow keys", () => {
    expect(keydownInput("a")).toBeUndefined();
    expect(keydownInput("Enter")).toBeUndefined();
    expect(keydownInput(" ")).toBeUndefined();
  });
});

describe("createPlaytestSession", () => {
  it("runs save-all → compile → boot → playing, then stop tears down", async () => {
    const phases: string[] = [];
    let booted: unknown = null;
    let tornDown = false;
    const session = createPlaytestSession({
      collectFlushes: () => [{ path: "m.yaml", content: "m" }],
      write: async () => {},
      compile: async () => ({ format: "nengine-bundle", version: 1, content: {} }),
      boot: async (bundle) => {
        booted = bundle;
      },
      teardown: async () => {
        tornDown = true;
      },
      onPhase: (phase) => phases.push(phase),
    });
    const result = await session.start();
    expect(result.ok).toBe(true);
    expect(result.saved).toEqual(["m.yaml"]);
    expect(booted).toEqual({ format: "nengine-bundle", version: 1, content: {} });
    expect(session.phase).toBe("playing");
    expect(phases).toEqual(["saving", "compiling", "booting", "playing"]);

    await session.stop();
    expect(tornDown).toBe(true);
    expect(session.phase).toBe("idle");
    expect(phases[phases.length - 1]).toBe("idle");
  });

  it("fails on an un-serializable model and never compiles", async () => {
    let compiled = false;
    const session = createPlaytestSession({
      collectFlushes: () => [{ path: "bad.yaml", error: "map invalid" }],
      write: async () => {},
      compile: async () => {
        compiled = true;
        throw new Error("nope");
      },
      boot: async () => {},
      teardown: async () => {},
    });
    const result = await session.start();
    expect(result.ok).toBe(false);
    expect(result.saved).toEqual([]);
    expect(result.error).toContain("bad.yaml");
    expect(result.error).toContain("map invalid");
    expect(compiled).toBe(false);
    expect(session.phase).toBe("idle");
  });

  it("fails on a write rejection", async () => {
    const session = createPlaytestSession({
      collectFlushes: () => [{ path: "a.yaml", content: "a" }],
      write: async () => {
        throw new Error("disk full");
      },
      compile: async () => {
        throw new Error("unreachable");
      },
      boot: async () => {},
      teardown: async () => {},
    });
    const result = await session.start();
    expect(result.ok).toBe(false);
    expect(result.saved).toEqual([]);
    expect(result.error).toContain("disk full");
  });

  it("fails on a compile error with the compile message", async () => {
    let booted = false;
    const session = createPlaytestSession({
      collectFlushes: () => [],
      write: async () => {},
      compile: async () => {
        throw new Error("content validation failed");
      },
      boot: async () => {
        booted = true;
      },
      teardown: async () => {},
    });
    const result = await session.start();
    expect(result.ok).toBe(false);
    expect(result.error).toContain("content validation failed");
    expect(booted).toBe(false);
    expect(session.phase).toBe("idle");
  });

  it("fails on a boot error with the boot message", async () => {
    const session = createPlaytestSession({
      collectFlushes: () => [],
      write: async () => {},
      compile: async () => ({ format: "nengine-bundle", version: 1, content: {} }),
      boot: async () => {
        throw new Error("no map content loaded");
      },
      teardown: async () => {},
    });
    const result = await session.start();
    expect(result.ok).toBe(false);
    expect(result.error).toContain("no map content loaded");
    expect(session.phase).toBe("idle");
  });

  it("rejects start while already running", async () => {
    let resolveBoot: (() => void) | undefined;
    const session = createPlaytestSession({
      collectFlushes: () => [],
      write: async () => {},
      compile: async () => ({ format: "nengine-bundle", version: 1, content: {} }),
      boot: async () => {
        await new Promise<void>((resolve) => {
          resolveBoot = resolve;
        });
      },
      teardown: async () => {},
    });
    const first = session.start();
    await Promise.resolve();
    const second = await session.start();
    expect(second.ok).toBe(false);
    expect(second.error).toBe("playtest already running");
    resolveBoot?.();
    await first;
    expect(session.phase).toBe("playing");
  });

  it("stop is a no-op when idle", async () => {
    let tornDown = false;
    const session = createPlaytestSession({
      collectFlushes: () => [],
      write: async () => {},
      compile: async () => ({ format: "nengine-bundle", version: 1, content: {} }),
      boot: async () => {},
      teardown: async () => {
        tornDown = true;
      },
    });
    await session.stop();
    expect(tornDown).toBe(false);
    expect(session.phase).toBe("idle");
  });
});