import {
    describe,
    expect,
    it,
} from 'vitest';
import { computeStrutHeight } from './computeStrutHeight';

describe('computeStrutHeight', () => {
    it('uses the centering height when the line-height is generous', () => {
        // centering = 40/2 + 16*0.34 = 25.44; floor = 16*1.1 = 17.6 → centering wins.
        expect(computeStrutHeight(40, 16)).toBeCloseTo(25.44, 5);
    });

    it('falls back to the ascent floor when the line-height is tight', () => {
        // centering = 16/2 + 16*0.34 = 13.44; floor = 16*1.1 = 17.6 → floor wins.
        expect(computeStrutHeight(16, 16)).toBeCloseTo(17.6, 5);
    });

    it('treats the floor and centering height as equal at the crossover line-height', () => {
        // centering == floor when lineHeight = 1.52 * fontSize → 24.32 for 16px.
        expect(computeStrutHeight(24.32, 16)).toBeCloseTo(17.6, 5);
    });

    it('scales with font size', () => {
        // centering = 60/2 + 32*0.34 = 40.88; floor = 32*1.1 = 35.2 → centering wins.
        expect(computeStrutHeight(60, 32)).toBeCloseTo(40.88, 5);
    });
});