import { test } from "node:test";
import assert from "node:assert/strict";
import { add, complete, remove, format } from "../src/todo.js";

test("add appends an open todo", () => {
  const todos = add([], "buy milk");
  assert.deepEqual(todos, [{ id: 1, text: "buy milk", done: false }]);
});

test("complete marks only the matching todo", () => {
  const todos = complete(add(add([], "a"), "b"), 2);
  assert.equal(todos[0].done, false);
  assert.equal(todos[1].done, true);
});

test("remove drops the matching todo", () => {
  const todos = remove(add(add([], "a"), "b"), 1);
  assert.deepEqual(todos.map((t) => t.text), ["b"]);
});

test("format renders an empty list", () => {
  assert.equal(format([]), "Nothing to do.");
});