@sanity/visual-editing/dist-svelte/hooks.js

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import crypto from 'crypto';
import { validatePreviewUrl } from '@sanity/preview-url-secret';
import { redirect as defaultRedirect, error } from '@sveltejs/kit';
/**
 * @public
 */
export const handlePreview = ({ client, preview }) => {
    const cookieName = preview?.cookie || '__sanity_preview';
    const enablePath = preview?.endpoints?.enable || '/preview/enable';
    const disablePath = preview?.endpoints?.disable || '/preview/disable';
    const secret = preview?.secret || crypto.randomBytes(16).toString('hex');
    const redirect = preview?.redirect || defaultRedirect;
    if (!client)
        throw new Error('No client configured for preview');
    return async ({ event, resolve }) => {
        const { cookies, url } = event;
        // Check the cookie to see if it preview is enabled
        event.locals.preview = event.cookies.get(cookieName) === secret;
        // Set default perspective and useCdn based on preview status
        const perspective = event.locals.preview ? 'drafts' : 'published';
        const useCdn = event.locals.preview ? false : true;
        // Check if the request is to enable or disable previews
        if (event.url.pathname === enablePath) {
            const { isValid, redirectTo = '/' } = await validatePreviewUrl(client, url.toString());
            if (!isValid) {
                throw error(401, 'Invalid secret');
            }
            const devMode = process.env['NODE_ENV'] === 'development';
            cookies.set(cookieName, secret, {
                httpOnly: true,
                sameSite: devMode ? 'lax' : 'none',
                secure: !devMode,
                path: '/',
            });
            return redirect(307, redirectTo);
        }
        if (event.url.pathname === disablePath) {
            cookies.delete(cookieName, { path: '/' });
            return redirect(307, url.searchParams.get('redirect') || '/');
        }
        // Add client to event locals with the defaults set above
        event.locals.client = client.withConfig({
            perspective,
            useCdn,
        });
        return await resolve(event);
    };
};