state-synchronizers/dist/create-state-synchronizer.test.js

Deterministically update state based on other state

"use strict";
var __assign = (this && this.__assign) || function () {
    __assign = Object.assign || function(t) {
        for (var s, i = 1, n = arguments.length; i < n; i++) {
            s = arguments[i];
            for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
                t[p] = s[p];
        }
        return t;
    };
    return __assign.apply(this, arguments);
};
exports.__esModule = true;
var create_state_synchronizer_1 = require("./create-state-synchronizer");
describe('createStateSynchronizer', function () {
    it('should return a function', function () {
        expect.hasAssertions();
        var result = create_state_synchronizer_1.createStateSynchronizer(jest.fn(), ['a', 'b']);
        expect(result).toBeInstanceOf(Function);
    });
    describe('returned state synchronizer', function () {
        var initialState = {
            name: 'John',
            age: 10,
            legalAge: false
        };
        var updateLegalAge = jest.fn(function (state) { return (__assign(__assign({}, state), { legalAge: state.age >= 21 })); });
        beforeEach(function () {
            jest.clearAllMocks();
        });
        it('should run the updater when a dependency changed', function () {
            expect.hasAssertions();
            var legalAgeSynchronizer = create_state_synchronizer_1.createStateSynchronizer(updateLegalAge, [
                'age',
            ]);
            var newState = __assign(__assign({}, initialState), { age: 11 });
            var result = legalAgeSynchronizer(newState, initialState);
            expect(updateLegalAge).toHaveBeenCalledTimes(1);
            expect(updateLegalAge).toHaveBeenCalledWith(newState);
            expect(result).toStrictEqual(updateLegalAge.mock.results[0].value);
        });
        it('should not run the updater when no dependencies changed', function () {
            expect.hasAssertions();
            var legalAgeSynchronizer = create_state_synchronizer_1.createStateSynchronizer(updateLegalAge, [
                'age',
            ]);
            var newState = __assign(__assign({}, initialState), { name: 'Ann' });
            var result = legalAgeSynchronizer(newState, initialState);
            expect(updateLegalAge).not.toHaveBeenCalled();
            expect(result).toStrictEqual(newState);
        });
        it('should not call the updater when the dependencies array is empty', function () {
            expect.hasAssertions();
            var legalAgeSynchronizer = create_state_synchronizer_1.createStateSynchronizer(updateLegalAge, []);
            var newState = { name: 'Ann', age: 50, legalAge: true };
            var result = legalAgeSynchronizer(newState, initialState);
            expect(updateLegalAge).not.toHaveBeenCalled();
            expect(result).toStrictEqual(newState);
        });
    });
});