@fedify/fedify/esm/federation/router.js

An ActivityPub server framework

// @ts-ignore TS7016
import { Router as InnerRouter } from "uri-template-router";
import { parseTemplate } from "url-template";
/**
 * URL router and constructor based on URI Template
 * ([RFC 6570](https://tools.ietf.org/html/rfc6570)).
 */
export class Router {
    #router;
    #templates;
    #templateStrings;
    #trailingSlashInsensitive;
    /**
     * Create a new {@link Router}.
     * @param options Options for the router.
     */
    constructor(options = {}) {
        this.#router = new InnerRouter();
        this.#templates = {};
        this.#templateStrings = {};
        this.#trailingSlashInsensitive = options.trailingSlashInsensitive ?? false;
    }
    /**
     * Checks if a path name exists in the router.
     * @param name The name of the path.
     * @returns `true` if the path name exists, otherwise `false`.
     */
    has(name) {
        return name in this.#templates;
    }
    /**
     * Adds a new path rule to the router.
     * @param template The path pattern.
     * @param name The name of the path.
     * @returns The names of the variables in the path pattern.
     */
    add(template, name) {
        if (!template.startsWith("/")) {
            throw new RouterError("Path must start with a slash.");
        }
        const rule = this.#router.addTemplate(template, {}, name);
        this.#templates[name] = parseTemplate(template);
        this.#templateStrings[name] = template;
        return new Set(rule.variables.map((v) => v.varname));
    }
    /**
     * Resolves a path name and values from a URL, if any match.
     * @param url The URL to resolve.
     * @returns The name of the path and its values, if any match.  Otherwise,
     *          `null`.
     */
    route(url) {
        let match = this.#router.resolveURI(url);
        if (match == null) {
            if (!this.#trailingSlashInsensitive)
                return null;
            url = url.endsWith("/") ? url.replace(/\/+$/, "") : `${url}/`;
            match = this.#router.resolveURI(url);
            if (match == null)
                return null;
        }
        return {
            name: match.matchValue,
            template: this.#templateStrings[match.matchValue],
            values: match.params,
        };
    }
    /**
     * Constructs a URL/path from a path name and values.
     * @param name The name of the path.
     * @param values The values to expand the path with.
     * @returns The URL/path, if the name exists.  Otherwise, `null`.
     */
    build(name, values) {
        if (name in this.#templates) {
            return this.#templates[name].expand(values);
        }
        return null;
    }
}
/**
 * An error thrown by the {@link Router}.
 */
export class RouterError extends Error {
    /**
     * Create a new {@link RouterError}.
     * @param message The error message.
     */
    constructor(message) {
        super(message);
        this.name = "RouterError";
    }
}