import { describe, expect, test } from "bun:test";
import { parseScanLimit } from "../scan";

describe("parseScanLimit", () => {
	test("accepts positive integers and nullish/empty as no-limit", () => {
		expect(parseScanLimit(5)).toEqual({ ok: true, value: 5 });
		expect(parseScanLimit(1)).toEqual({ ok: true, value: 1 });
		expect(parseScanLimit(10_000)).toEqual({ ok: true, value: 10_000 });
		expect(parseScanLimit(null)).toEqual({ ok: true, value: null });
		expect(parseScanLimit(undefined)).toEqual({ ok: true, value: null });
		expect(parseScanLimit("")).toEqual({ ok: true, value: null });
	});

	test("coerces numeric strings (env var path) but rejects garbage", () => {
		expect(parseScanLimit("7")).toEqual({ ok: true, value: 7 });
		expect(parseScanLimit("abc")).toEqual({ ok: false });
		expect(parseScanLimit("12abc")).toEqual({ ok: false });
	});

	test("rejects the footguns that would silently disable the cap", () => {
		// NaN: processed >= NaN never trips → cap never fires.
		expect(parseScanLimit(Number.NaN)).toEqual({ ok: false });
		// Negative: off-by-one bugs in Math.min(limit, total).
		expect(parseScanLimit(-1)).toEqual({ ok: false });
		expect(parseScanLimit(0)).toEqual({ ok: false });
		// Float: Math.min is fine but percentage math breaks on non-integers.
		expect(parseScanLimit(1.5)).toEqual({ ok: false });
		// Infinity is technically a number but has no business as a cap.
		expect(parseScanLimit(Number.POSITIVE_INFINITY)).toEqual({ ok: false });
	});
});