123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172
/** * This module provides canonicalization of JSON trees.  This complies with * RFC 8785, also known as JCS (JSON Canonicalization Scheme). * @license LGPL-3.0-or-later */
/** * Represents a JSON tree. */export type Tree =  | null  | boolean  | number  | string  | TreeArray  | TreeObject;
// deno-lint-ignore no-empty-interfaceinterface TreeArray extends Array<Tree> {}
interface TreeObject {  [_: string]: Tree;}
function serialize(tree: Tree, buffer: string[]): void {  if (tree == null || typeof tree !== "object") {    // ES6 JSON partially complies with RFC 8785 (JCS: JSON Canonicalization    // Scheme) except for objects and arrays:    buffer.push(JSON.stringify(tree));  } else if (Array.isArray(tree)) {    buffer.push("[");    let notFirst = false;    for (const item of tree) {      if (notFirst) {        buffer.push(",");      }      notFirst = true;      serialize(item, buffer);    }    buffer.push("]");  } else {    // Object keys must be sorted in JSON.    const keys = Object.keys(tree);    keys.sort();    buffer.push("{");    let notFirst = false;    for (const key of keys) {      if (notFirst) {        buffer.push(",");      }      notFirst = true;      buffer.push(JSON.stringify(key));      buffer.push(":");      serialize(tree[key], buffer);    }    buffer.push("}");  }}
/** * Serializes a tree into a JSON string which complies with RFC 8785 * (JCS: JSON Canonicalization Scheme). * @param tree The tree to serialize. * @returns The canonicalized JSON string. */export function canonicalize(tree: Tree): string {  const buffer: string[] = [];  serialize(tree, buffer);  return buffer.join("");}