recoil/cjs/recoil_values/__tests__/Recoil_constSelector-test.js.flow

Recoil - A state management library for React

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @emails oncall+recoil
 * @flow strict-local
 * @format
 */
'use strict';

import type { RecoilValue } from '../../core/Recoil_RecoilValue';

const {
  getRecoilTestFn
} = require('../../__test_utils__/Recoil_TestingUtils');

let getRecoilValueAsLoadable, store, constSelector;
const testRecoil = getRecoilTestFn(() => {
  const {
    makeStore
  } = require('../../__test_utils__/Recoil_TestingUtils');

  ({
    getRecoilValueAsLoadable
  } = require('../../core/Recoil_RecoilValueInterface'));
  constSelector = require('../Recoil_constSelector');
  store = makeStore();
});
declare function get<T>(recoilValue: RecoilValue<T>): T;
testRecoil('constSelector - string', () => {
  const mySelector = constSelector('HELLO');
  expect(get(mySelector)).toEqual('HELLO');
  expect(get(mySelector)).toBe('HELLO');
});
testRecoil('constSelector - number', () => {
  const mySelector = constSelector(42);
  expect(get(mySelector)).toEqual(42);
  expect(get(mySelector)).toBe(42);
});
testRecoil('constSelector - null', () => {
  const mySelector = constSelector(null);
  expect(get(mySelector)).toEqual(null);
  expect(get(mySelector)).toBe(null);
});
testRecoil('constSelector - boolean', () => {
  const mySelector = constSelector(true);
  expect(get(mySelector)).toEqual(true);
  expect(get(mySelector)).toBe(true);
});
testRecoil('constSelector - array', () => {
  const emptyArraySelector = constSelector([]);
  expect(get(emptyArraySelector)).toEqual([]);
  const numberArray = [1, 2, 3];
  const numberArraySelector = constSelector(numberArray);
  expect(get(numberArraySelector)).toEqual([1, 2, 3]);
  expect(get(numberArraySelector)).toBe(numberArray);
});
testRecoil('constSelector - object', () => {
  const emptyObjSelector = constSelector({});
  expect(get(emptyObjSelector)).toEqual({});
  const obj = {
    foo: 'bar'
  };
  const objSelector = constSelector(obj);
  expect(get(objSelector)).toEqual({
    foo: 'bar'
  });
  expect(get(objSelector)).toBe(obj); // Calling a second time with same object provides the same selector

  const objSelector2 = constSelector(obj);
  expect(objSelector2).toBe(objSelector);
  expect(get(objSelector2)).toEqual({
    foo: 'bar'
  });
  expect(get(objSelector2)).toBe(obj); // Calling a third time with similar but different object provides
  // a new selector for the new reference.

  const newObj = {
    foo: 'bar'
  };
  const objSelector3 = constSelector(newObj);
  expect(get(objSelector3)).toEqual({
    foo: 'bar'
  });
  expect(get(objSelector3)).toBe(newObj);
});
testRecoil('constSelector - function', () => {
  declare var foo: () => any;
  declare var bar: () => any;
  const fooSelector = constSelector(foo);
  const barSelector = constSelector(bar);
  expect(get(fooSelector)()).toEqual('FOO');
  expect(get(barSelector)()).toEqual('BAR');
  expect(constSelector(foo)).toEqual(fooSelector);
});