image.test.js — astro Source File

Source Code

import assert from 'node:assert/strict';
import { after, before, describe, it } from 'node:test';
import * as cheerio from 'cheerio';
import { loadFixture } from './test-utils.js';

describe('Image', () => {
	/** @type {import('./test-utils.js').Fixture} */
	let fixture;

	before(async () => {
		fixture = await loadFixture({
			root: './fixtures/image/',
		});
		await fixture.build();
	});

	it('build successful', async () => {
		assert.ok(await fixture.readFile('../.vercel/output/static/index.html'));
	});

	it('has link to vercel in build with proper attributes', async () => {
		const html = await fixture.readFile('../.vercel/output/static/index.html');
		const $ = cheerio.load(html);
		const img = $('#basic-image img');

		assert.equal(img.attr('src').startsWith('/_vercel/image?url=_astr'), true);
		assert.equal(img.attr('loading'), 'lazy');
		assert.equal(img.attr('width'), '225');
	});

	it('generates valid image sizes when requested width is larger than source image', async () => {
		const html = await fixture.readFile('../.vercel/output/static/index.html');
		const $ = cheerio.load(html);
		const img = $('#small-source img');
		const widths = img
			.attr('srcset')
			.split(', ')
			.map((entry) => entry.split(' ')[1]);
		assert.deepEqual(widths, ['640w'], 'uses valid widths in srcset');

		const url = new URL(img.attr('src'), 'http://localhost');
		assert.equal(url.searchParams.get('w'), '640', 'uses valid width in src');

		assert.equal(img.attr('width'), '225', 'uses requested width in img attribute');
	});

	it('generates valid densities-based srcset using only configured sizes', async () => {
		const html = await fixture.readFile('../.vercel/output/static/index.html');
		const $ = cheerio.load(html);
		const img = $('#densities-test img');
		const srcset = img.attr('srcset');

		// Extract widths from srcset (format: "url 1x", "url 1.5x", etc)
		const descriptors = srcset.split(', ').map((entry) => entry.split(' ')[1]);

		// Extract the widths from the URLs (they should be valid configured sizes)
		const urls = srcset.split(', ').map((entry) => entry.split(' ')[0]);
		const widthsFromUrls = urls.map((url) => {
			const urlObj = new URL(url, 'http://localhost');
			return parseInt(urlObj.searchParams.get('w'), 10);
// ... (87 more lines)