bun.sh/test/js/web/explicit-resource-management.test.ts

// tbh, we should have more tests for this
test("Symbol.dispose exists", () => {
  expect(Symbol.dispose).toBeDefined();
  expect(Symbol.dispose).toBeSymbol();
  expect(Symbol.asyncDispose).toBeDefined();
  expect(Symbol.asyncDispose).toBeSymbol();
});

test("SuppressedError works", () => {
  const e = new SuppressedError(new Error("this is error"), new Error("this was suppressed"), "this is a message");
  expect(e.message).toBe("this is a message");
  expect(() => {
    throw e.suppressed;
  }).toThrow("this was suppressed");
  expect(() => {
    throw e.error;
  }).toThrow("this is error");
});

let disposeOrder = 0;
function useWithAsync() {
  return {
    status: "none",
    disposeOrder: -1,
    [Symbol.dispose]() {
      this.status = "disposed";
      this.disposeOrder = disposeOrder++;
    },
    [Symbol.asyncDispose]() {
      this.status = "async-disposed";
      this.disposeOrder = disposeOrder++;
    },
  };
}

test("using syntax works and doesnt collide with user symbols", () => {
  disposeOrder = 0;
  {
    let __using = "break";
    let __callDispose = function () {
      throw new Error("should not be called");
    };
    let __stack = {
      push: () => {
        throw new Error("stack corruption");
      },
    };

    const a1 = useWithAsync();
    {
      using u1 = a1;
      expect(u1.status).toBe("none");
    }
    expect(a1.status).toBe("disposed");
  }

  {
    const a1 = useWithAsync();
    const a2 = useWithAsync();
    const a3 = useWithAsync();
    {
      using u1 = a1,
        u2 = a2;
      {
        using u3 = a3;
        expect(u3.status).toBe("none");
      }
      expect(u1.status).toBe("none");
      expect(u2.status).toBe("none");
      expect(a3.status).toBe("disposed");
    }
    expect(a1.status).toBe("disposed");
    expect(a2.status).toBe("disposed");

    expect(a3.disposeOrder).toBe(1);
    expect(a2.disposeOrder).toBe(2);
    expect(a1.disposeOrder).toBe(3);
  }

  const a1 = useWithAsync();
  {
    using u1 = a1;
    {
      var __stack = 1;
      var _catch = 1;
      var _err = 1;
      var _hasErr = 1;
    }
  }
});

test("await using syntax works and doesnt collide with user symbols", async () => {
  disposeOrder = 0;
  {
    let __using = "break";
    let __callDispose = function () {
      throw new Error("should not be called");
    };
    let __stack = {
      push: () => {
        throw new Error("stack corruption");
      },
    };

    const a1 = useWithAsync();
    {
      using u1 = a1;
      expect(u1.status).toBe("none");
    }
    expect(a1.status).toBe("disposed");
  }

  {
    const a1 = useWithAsync();
    const a2 = useWithAsync();
    const a3 = useWithAsync();
    {
      using u1 = a1;
      await using u2 = a2;
      {
        using u3 = a3;
        expect(u3.status).toBe("none");
      }
      expect(u1.status).toBe("none");
      expect(u2.status).toBe("none");
      expect(a3.status).toBe("disposed");
    }
    expect(a1.status).toBe("disposed");
    expect(a2.status).toBe("async-disposed");

    expect(a3.disposeOrder).toBe(1);
    expect(a2.disposeOrder).toBe(2);
    expect(a1.disposeOrder).toBe(3);
  }

  const a1 = useWithAsync();
  {
    await using u1 = a1;
    {
      var __stack = 1;
      var _catch = 1;
      var _err = 1;
      var _hasErr = 1;
    }
  }
});