import { describe, it, expect } from "vitest";
import { normalizeWhitespace } from "../../extensions/compress/stages/whitespace.js";

describe("normalizeWhitespace", () => {
	it("returns unchanged string when already clean", () => {
		const text = "line one\nline two\nline three";
		expect(normalizeWhitespace(text)).toBe(text);
	});

	it("strips trailing spaces from lines", () => {
		expect(normalizeWhitespace("line   \nother")).toBe("line\nother");
	});

	it("strips trailing tabs from lines", () => {
		expect(normalizeWhitespace("line\t\t\nother")).toBe("line\nother");
	});

	it("collapses 3+ blank lines to 2", () => {
		expect(normalizeWhitespace("a\n\n\n\n\nb")).toBe("a\n\nb");
		expect(normalizeWhitespace("a\n\n\nb")).toBe("a\n\nb");
	});

	it("leaves exactly 2 blank lines intact", () => {
		const text = "a\n\n\nb";
		expect(normalizeWhitespace(text)).toBe("a\n\nb");
		// 2 blank lines = 3 newlines total → collapses to 2 newlines
		const twoNewlines = "a\n\nb";
		expect(normalizeWhitespace(twoNewlines)).toBe(twoNewlines);
	});

	it("strips leading blank lines", () => {
		expect(normalizeWhitespace("\n\nline")).toBe("line");
		expect(normalizeWhitespace("\nline")).toBe("line");
	});

	it("strips trailing blank lines", () => {
		expect(normalizeWhitespace("line\n\n")).toBe("line");
	});

	it("handles empty string", () => {
		expect(normalizeWhitespace("")).toBe("");
	});

	it("handles string with only whitespace", () => {
		const result = normalizeWhitespace("\n\n\n");
		// All newlines → collapses to max 2, then leading stripped
		expect(result).toBe("");
	});

	it("combined: strips trailing spaces, collapses blanks, strips leading/trailing blank lines", () => {
		const input = "\n\nfoo   \nbar  \n\n\n\nbaz\n\n";
		const expected = "foo\nbar\n\nbaz";
		expect(normalizeWhitespace(input)).toBe(expected);
	});
});