logolite/lib/format.js

Lite Virtual Logger and Writer

'use strict';

const argPattern = /(\{|\$\{|\#\{)[\s]*([0-9]+|[a-zA-Z_][0-9a-zA-Z_\.]*[0-9a-zA-Z_])[\s]*(\})/g;
const notFoundValue = process.env.LOGOLITE_FORMAT_NOT_FOUND_VALUE || 'not_found_value';
const stringifyFailed = process.env.LOGOLITE_STRINGIFY_FAILED_VALUE || 'stringify_failed';
function transform(a) {
  let b;
  if (arguments.length === 2 && typeof arguments[1] === "object") {
    b = arguments[1];
  } else {
    b = Array.prototype.slice.call(arguments, 1);
  }
  if (!b || !b.hasOwnProperty) b = {};
  return a.replace(argPattern, function h(c, d, f, g, e) {
    if (a[e - 1] === "{" && d === "{" && a[e + c.length] === "}") {
      return f; // transform {{variable}} to {variable}
    } else if (a[e - 1] === "$" && d === "${") {
      return "{" + f + "}"; // transform $${variable} to ${variable}
    } else if (a[e - 1] === "#" && d === "#{") {
      return "{" + f + "}"; // transform ##{variable} to #{variable}
    } else {
      let a = b.hasOwnProperty(f) ? b[f] : null;
      if (a === null || a === undefined) {
        let c = f.split('.');
        if (c.length > 1) {
          a = c.reduce(function (a, b) {
            return a && a.hasOwnProperty(b) ? a[b] : null;
          }, b);
        }
      }
      if (a === null || a === undefined) return notFoundValue;
      if (typeof a === "object") return stringify(a);
      return a;
    }
  });
}
function stringify(a) {
  try {
    return JSON.stringify(a);
  } catch (a) {}
  return stringifyFailed;
}
module.exports = transform;