@fastly/esi/build/EsiTransformStream.js

ESI implementation for JavaScript, using the modern fetch and streaming APIs.

/*
 * Copyright Fastly, Inc.
 * Licensed under the MIT license. See LICENSE file for details.
 */
import XmlTransformStream from "./XmlTransformStream.js";
import EsiTransformer, { EsiError } from "./EsiTransformer.js";
import { XmlDocument } from "./XmlModel.js";
import { EsiVariables } from "./EsiVariables.js";
export default class EsiTransformStream extends XmlTransformStream {
    constructor(url, headers, options, depth = 0) {
        const transformerOpts = {
            ...options,
        };
        transformerOpts.vars ??= new EsiVariables(new URL(url), new Headers(headers));
        const esiTransformer = new EsiTransformer(url, headers, {
            async processIncludeResponse(result) {
                if (result.res.body == null) {
                    // we have no 'body'? I guess the response can just be an empty string
                    return '';
                }
                const innerEsiTransformStream = new EsiTransformStream(result.url, result.headers, transformerOpts, depth + 1);
                const innerTransformed = result.res.body.pipeThrough(innerEsiTransformStream);
                const tempResp = new Response(innerTransformed);
                return await tempResp.text();
            },
            ...transformerOpts,
        }, depth);
        const esiPrefix = options?.esiPrefix;
        const namespaceDefs = {};
        if (esiPrefix === null) {
            // We create a document with no namespace definitions
        }
        else {
            if (esiPrefix != null && !/^[a-zA-Z][-a-zA-Z0-9]*$/.test(esiPrefix)) {
                throw new EsiError(`ESI namespace prefix '${esiPrefix}' is not a valid identifier.`);
            }
            // If esiPrefix is undefined, we use the default of 'esi'.
            namespaceDefs[esiPrefix ?? 'esi'] = EsiTransformer.namespace;
        }
        const document = new XmlDocument(namespaceDefs, true);
        // We ignore default (non-namespaced) tags. Only ESI and other namespaced tags
        // are expected to follow XML rules.
        const ignoreDefaultTags = true;
        super(document, esiTransformer, ignoreDefaultTags);
    }
}