change-string-case/node_modules/before-after-hook/lib/add.js

module.exports = addHook;

function addHook(state, kind, name, hook) {
  var orig = hook;
  if (!state.registry[name]) {
    state.registry[name] = [];
  }

  if (kind === "before") {
    hook = function (method, options) {
      return Promise.resolve()
        .then(orig.bind(null, options))
        .then(method.bind(null, options));
    };
  }

  if (kind === "after") {
    hook = function (method, options) {
      var result;
      return Promise.resolve()
        .then(method.bind(null, options))
        .then(function (result_) {
          result = result_;
          return orig(result, options);
        })
        .then(function () {
          return result;
        });
    };
  }

  if (kind === "error") {
    hook = function (method, options) {
      return Promise.resolve()
        .then(method.bind(null, options))
        .catch(function (error) {
          return orig(error, options);
        });
    };
  }

  state.registry[name].push({
    hook: hook,
    orig: orig,
  });
}