src/utils.js
function mergeYamls(file1, file2) {
  const obj1 = yaml.safeLoad(fileToString(file1), { schema: yamlfiles.YAML_FILES_SCHEMA });
  const obj2 = yaml.safeLoad(fileToString(file2), { schema: yamlfiles.YAML_FILES_SCHEMA });

  return yaml.safeDump(merge({}, obj1, obj2));
}
function mergeYamls(file1, file2) {
  const obj1 = yaml.safeLoad(fileToString(file1), { schema: yamlfiles.YAML_FILES_SCHEMA });
  const obj2 = yaml.safeLoad(fileToString(file2), { schema: yamlfiles.YAML_FILES_SCHEMA });

  return yaml.safeDump(merge({}, obj1, obj2));
}
Merges two yaml files. The merge is done using lodash.merge
and it happens recursively. Meaning that values of file2 will
replace values of file 1 if they have the same key.

@param {String} file1 Yaml path to file 1 or file 1 string
@param {String} file2 Yaml path to file 2 or file 2 string
@returns {String} Merged Yaml file in string format