@remix-run/headers/dist/lib/if-match.js

A toolkit for working with HTTP headers in JavaScript

import {} from "./header-value.js";
import { quoteEtag } from "./utils.js";
/**
 * The value of an `If-Match` HTTP header.
 *
 * [MDN `If-Match` Reference](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/If-Match)
 *
 * [HTTP/1.1 Specification](https://datatracker.ietf.org/doc/html/rfc7232#section-3.1)
 */
export class IfMatch {
    tags = [];
    /**
     * @param init A string, array of strings, or object to initialize the header
     */
    constructor(init) {
        if (init) {
            if (typeof init === 'string') {
                this.tags.push(...init.split(/\s*,\s*/).map(quoteEtag));
            }
            else if (Array.isArray(init)) {
                this.tags.push(...init.map(quoteEtag));
            }
            else {
                this.tags.push(...init.tags.map(quoteEtag));
            }
        }
    }
    /**
     * Checks if the header contains the given entity tag.
     *
     * Note: This method checks only for exact matches and does not consider wildcards.
     *
     * @param tag The entity tag to check for
     * @return `true` if the tag is present in the header, `false` otherwise
     */
    has(tag) {
        return this.tags.includes(quoteEtag(tag));
    }
    /**
     * Checks if the precondition passes for the given entity tag.
     *
     * This method always returns `true` if the `If-Match` header is not present
     * since the precondition passes regardless of the entity tag being checked.
     *
     * Uses strong comparison as per RFC 9110, meaning weak entity tags (prefixed with `W/`)
     * will never match.
     *
     * @param tag The entity tag to check against
     * @return `true` if the precondition passes, `false` if it fails (should return 412)
     */
    matches(tag) {
        if (this.tags.length === 0) {
            return true;
        }
        // Wildcard always matches (regardless of weak/strong)
        if (this.tags.includes('*')) {
            return true;
        }
        let normalizedTag = quoteEtag(tag);
        // Weak tags never match in If-Match (strong comparison only)
        if (normalizedTag.startsWith('W/')) {
            return false;
        }
        // Only match against strong tags in the header
        for (let headerTag of this.tags) {
            if (!headerTag.startsWith('W/') && headerTag === normalizedTag) {
                return true;
            }
        }
        return false;
    }
    /**
     * Returns the string representation of the header value.
     *
     * @return The header value as a string
     */
    toString() {
        return this.tags.join(', ');
    }
}