shared.ts — astro Source File

Source Code

// @ts-expect-error
import { imageConfig } from 'astro:assets';
import { isRemotePath, removeQueryString } from '@astrojs/internal-helpers/path';
import { isRemoteAllowed } from '@astrojs/internal-helpers/remote';
import * as mime from 'mrmime';
import { getConfiguredImageService } from '../internal.js';
import { etag } from '../utils/etag.js';

export async function loadRemoteImage(src: URL): Promise<Buffer | undefined> {
	try {
		const res = await fetch(src);

		if (!res.ok) {
			return undefined;
		}

		return Buffer.from(await res.arrayBuffer());
	} catch {
		return undefined;
	}
}

export const handleImageRequest = async ({
	request,
	loadLocalImage,
}: {
	request: Request;
	loadLocalImage: (src: string, baseUrl: URL) => Promise<Buffer | undefined>;
}) => {
	const imageService = await getConfiguredImageService();

	if (!('transform' in imageService)) {
		throw new Error('Configured image service is not a local service');
	}

	const url = new URL(request.url);
	const transform = await imageService.parseURL(url, imageConfig);

	if (!transform?.src) {
		return new Response('Invalid request', { status: 400 });
	}

	let inputBuffer: Buffer | undefined = undefined;

	if (isRemotePath(transform.src)) {
		if (!isRemoteAllowed(transform.src, imageConfig)) {
			return new Response('Forbidden', { status: 403 });
		}

		inputBuffer = await loadRemoteImage(new URL(transform.src));
	} else {
		inputBuffer = await loadLocalImage(removeQueryString(transform.src), url);
	}

	if (!inputBuffer) {
		return new Response('Internal Server Error', { status: 500 });
	}

	const { data, format } = await imageService.transform(inputBuffer, transform, imageConfig);

	return new Response(data as Uint8Array<ArrayBuffer>, {
		status: 200,
		headers: {
			'Content-Type': mime.lookup(format) ?? `image/${format}`,
			'Cache-Control': 'public, max-age=31536000',
			ETag: etag(data.toString()),
			Date: new Date().toUTCString(),
		},
	});
};