fable/val Public Public: anyone can read this; nobody can change it.

/** The body contract: what it names, and what it refuses. */

import { expect, test } from "bun:test";

import { bodyProblems, meProblems } from "./body.ts";

const good = { id: "a", name: "A", x: 1, y: 2, angle: 0, alive: true, hp: 100, mate: false };

test("a well-formed body has no problems, and each missing or mistyped field is named", () => {

  expect(bodyProblems(good)).toEqual([]);

  const { alive: _, ...noAlive } = good;

  expect(bodyProblems({ ...noAlive, down: false })).toEqual(["body.alive should be a boolean, is undefined"]);

  expect(bodyProblems({ ...good, x: NaN })).toHaveLength(1);

  expect(bodyProblems(null)).toEqual(["body is not an object"]);

  expect(meProblems({ id: "a" })).toContain("me.ammo should be a number, is undefined");

});

test("`side` may be left out, but when it is sent it is a string", () => {

  expect(bodyProblems({ ...good, side: "north" })).toEqual([]);

  expect(bodyProblems({ ...good, side: 3 })).toEqual(["body.side should be a string, is 3"]);

});