import { describe, expect, test } from "bun:test";
import { count, intersperse, uniq } from "../array";

describe("intersperse", () => {
	test("inserts separator between elements", () => {
		const result = intersperse([1, 2, 3], () => 0);
		expect(result).toEqual([1, 0, 2, 0, 3]);
	});

	test("returns empty array for empty input", () => {
		expect(intersperse([], () => 0)).toEqual([]);
	});

	test("returns single element without separator", () => {
		expect(intersperse([1], () => 0)).toEqual([1]);
	});

	test("passes index to separator function", () => {
		const result = intersperse(["a", "b", "c"], (i) => `sep-${i}`);
		expect(result).toEqual(["a", "sep-1", "b", "sep-2", "c"]);
	});
});

describe("count", () => {
	test("counts matching elements", () => {
		expect(count([1, 2, 3, 4, 5], (x) => x > 3)).toBe(2);
	});

	test("returns 0 for empty array", () => {
		expect(count([], () => true)).toBe(0);
	});

	test("returns 0 when nothing matches", () => {
		expect(count([1, 2, 3], (x) => x > 10)).toBe(0);
	});

	test("counts all when everything matches", () => {
		expect(count([1, 2, 3], () => true)).toBe(3);
	});
});

describe("uniq", () => {
	test("removes duplicates", () => {
		expect(uniq([1, 2, 2, 3, 3, 3])).toEqual([1, 2, 3]);
	});

	test("preserves order of first occurrence", () => {
		expect(uniq([3, 1, 2, 1, 3])).toEqual([3, 1, 2]);
	});

	test("handles empty array", () => {
		expect(uniq([])).toEqual([]);
	});

	test("works with strings", () => {
		expect(uniq(["a", "b", "a"])).toEqual(["a", "b"]);
	});
});