gen_pdf_wk_loadConfig.js

const fsp = require("fs-promise");
const jsonschema = require("jsonschema");
const jsonSchemaDefaults = require("json-schema-defaults");
const merge = require("merge");
const path = require("path");

/**
  Load book.json or a specified file, and validate the content.
  And return with mixing with the default values.

  @param {string} filename The file containing the Json object
  @return {Object}
*/
function loadConfig(filename = "book.json") {
  return Promise.all([
    fsp.readJson(filename),
    fsp.readJson(path.join(__dirname, "gen_pdf_wk_config_schema.json"))
  ]).then(([book, schema]) => {
    new jsonschema.Validator().validate(book, schema, { throwError: true });
    return merge.recursive(true, jsonSchemaDefaults(schema), book);
  });
}

module.exports.loadConfig = loadConfig;