StoreWithSelectors.js

class MyStore extends Record({ a: 0, b: List() }) {
  constructor(values) {
    super(values);

    const mySelector = createSelector(
      [(record) => record.a, (record, arg) => arg],
      (a, arg) => a + arg
    );
    Object.defineProperty(this, 'mySelector',
      Object.getOwnPropertyDescriptor(values, 'mySelector') ||
      {
        value: function (...args) {
          return mySelector(this, ...args);
        },
      }
    );

    const myComputed = createSelector(
      [(record) => record.a],
      (a) => a * a
    );
    Object.defineProperty(this, 'myComputed',
      Object.getOwnPropertyDescriptor(values, 'myComputed') ||
      {
        get: function () {
          return myComputed(this);
        },
      }
    );

    copyProperty(values, this, 'mySelector', () => {
      const mySelector = createSelector(
        [(record) => record.a, (record, arg) => arg],
        (a, arg) => a + arg
      );

      return {
        value: function (...args) {
          return mySelector(this, ...args);
        },
      };
    });

    copyGetters(values, this, {
      myComputed: selector(
        ['a'],
        (a) => a * a,
      ),
    });

    copySelectors(values, this, {
      mySelector: selector(
        ['a', (record, arg) => arg],
        (a, arg) => a + arg,
        customEqualityChecker
      )),
    });

    copyProperties(values, this, {
      mySelector: () => selector(createSelector(
        [(record, arg) => record.a, (record, arg) => arg],
        (a, arg) => a + arg
      )),
      myComputed: () => getter(createComputed(
        ['a'],
        (a) => a * a
      )),
    });
  }
}