jsonfm/index.ts

JSON format for good presentation

/*
  change for npm modules.
  by Luiz Estácio.

  json-format v.1.1
  http://github.com/phoboslab/json-format

  Released under MIT license:
  http://www.opensource.org/licenses/mit-license.php
*/
var p: Array<any> = [],
  indentConfig = {
    tab: { char: '\t', size: 1 },
    space: { char: ' ', size: 4 }
  },
  configDefault = {
    type: 'tab'
  },
  push = function (m: any) { return '\\' + p.push(m) + '\\'; },
  pop = function (m: any, i: number) { return p[i - 1] },
  tabs = function (count: number, indentType: string | undefined) { return new Array(count + 1).join(indentType); };

function JSONFormat(json: string, indentType: string) {
  p = [];
  var out = "",
    indent = 0;

  // Extract backslashes and strings
  json = json
    .replace(/\\./g, push)
    .replace(/(".*?"|'.*?')/g, push)
    .replace(/\s+/, '');

  // Indent and insert newlines
  for (var i = 0; i < json.length; i++) {
    var c = json.charAt(i);

    switch (c) {
      case '{':
      case '[':
        out += c + "\n" + tabs(++indent, indentType);
        break;
      case '}':
      case ']':
        out += "\n" + tabs(--indent, indentType) + c;
        break;
      case ',':
        out += ",\n" + tabs(indent, indentType);
        break;
      case ':':
        out += ": ";
        break;
      default:
        out += c;
        break;
    }
  }

  // Strip whitespace from numeric arrays and put backslashes 
  // and strings back in
  out = out
    .replace(/\[[\d,\s]+?\]/g, function (m) { return m.replace(/\s/g, ''); })
    .replace(/\\(\d+)\\/g, pop) // strings
    .replace(/\\(\d+)\\/g, pop); // backslashes in strings

  return out;
};


interface jsonfConfig {
  type?: 'space' | "tab" | string;
  tab?: { char: '\t', size: 1 };
  space?: { char: ' ', size: 4 };
  [key: string]: { char: string, size: number } | string | undefined;
}

export = function (json: Array<any> | Object | string, config?: jsonfConfig): string {
  if (!config) {
    config = configDefault;
  }
  var indent = config.type as string | undefined ? indentConfig[config.type as "tab"] : indentConfig["tab"];

  if (indent == null) {
    throw new Error('Unrecognized indent type: "' + config.type + '"');
  }

  // @ts-expect-error
  var indentType = new Array((config.size || indent.size) + 1).join(indent.char);
  if (typeof json == "string") {
    return JSONFormat(json, indentType);

  } else
    return JSONFormat(JSON.stringify(json), indentType);
}

declare module 'jsonfm' {
  export {jsonfConfig}
}