import {it,expect} from 'vitest'
import {withPngDensity} from '../src/main/png-density'
// A small valid PNG; injecting resolution must not change its image payload.
const source=Buffer.from('iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+jvF8AAAAASUVORK5CYII=','base64')
it('PNG 带有实际 300 DPI 分辨率且可重复更新',()=>{
 const png=withPngDensity(source,300),index=png.indexOf('pHYs')
 expect(png.readUInt32BE(index+4)).toBe(11811);expect(png.readUInt32BE(index+8)).toBe(11811)
 const second=withPngDensity(png,150)
 expect(second.toString('latin1').split('pHYs')).toHaveLength(2)
 expect(second.readUInt32BE(second.indexOf('pHYs')+4)).toBe(5906)
})