every_test.ts

import { test } from "@cross/test";
import { assertEquals } from "@std/assert";
import { assertType, type IsExact } from "@std/testing/types";
import { every } from "./every.ts";

await test("every returns true if all elements satisfy the function", () => {
  const values: number[] = [];
  const indices: number[] = [];
  const result = every([1, 2, 3, 4, 5], (v, index) => {
    values.push(v);
    indices.push(index);
    return v < 6;
  });
  const expected = true;
  assertEquals(result, expected);
  assertEquals(values, [1, 2, 3, 4, 5]);
  assertEquals(indices, [0, 1, 2, 3, 4]);
  assertType<IsExact<typeof result, boolean>>(true);
});

await test(
  "every returns false if not all elements satisfy the function",
  () => {
    const values: number[] = [];
    const indices: number[] = [];
    const result = every([1, 2, 3, 4, 5], (v, index) => {
      values.push(v);
      indices.push(index);
      return v < 3;
    });
    const expected = false;
    assertEquals(result, expected);
    assertEquals(values, [1, 2, 3]);
    assertEquals(indices, [0, 1, 2]);
    assertType<IsExact<typeof result, boolean>>(true);
  },
);