import {test} from 'node:test';
import assert from 'node:assert/strict';
import sharp from 'sharp';
import {compressPreview,previewWidth,staticPreviewPath,cachedPreview} from '../src/lib/preview';
test('preview input validation rejects traversal and arbitrary sizes',()=>{for(const value of [1,10000,'bad'])assert.equal(previewWidth(value),null);assert.equal(previewWidth(480),480);for(const source of ['https://example.com/x.png','/../secret.png','//remote/x.png','/x.svg','/x.png?foo=bar'])assert.throws(()=>staticPreviewPath(source,'/public'));assert.equal(staticPreviewPath('/images/a.png','/public'),'/public/images/a.png');});
test('large PNG becomes a bounded WebP with no upscaling',async()=>{const original=await sharp({create:{width:2200,height:3000,channels:3,background:'#f0e2d2'}}).png().toBuffer();const preview=await compressPreview(original,480);const info=await sharp(preview).metadata();assert.equal(info.format,'webp');assert.equal(info.width,480);assert.ok(preview.length<=100000);});
test('identical concurrent requests share one transform and reuse the disk result',async()=>{let loads=0;const input=await sharp({create:{width:40,height:40,channels:3,background:'#fff'}}).png().toBuffer();const identity='test-'+Date.now();const load=async()=>{loads++;return input};const [a,b]=await Promise.all([cachedPreview(identity,480,load),cachedPreview(identity,480,load)]);assert.deepEqual(a.bytes,b.bytes);assert.equal(loads,1);await cachedPreview(identity,480,load);assert.equal(loads,1);});
test('export derivatives keep resolution and use an independent cache identity',async()=>{assert.equal(previewWidth(2160,'export'),2160);assert.equal(previewWidth(2160),null);assert.equal(previewWidth(480,'export'),null);const input=await sharp({create:{width:1800,height:1200,channels:3,background:'#eddfbd'}}).png().toBuffer();const identity='export-'+Date.now();const result=await cachedPreview(identity,2160,async()=>input,true);const meta=await sharp(result.bytes).metadata();assert.equal(meta.width,1800);assert.equal(meta.height,1200);const normal=await cachedPreview(identity,480,async()=>input);assert.notEqual(result.etag,normal.etag)});