state-synchronizers/dist/compose-state-synchronizers.test.js

Deterministically update state based on other state

"use strict";
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    __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];
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exports.__esModule = true;
var compose_state_synchronizers_1 = require("./compose-state-synchronizers");
var create_composable_state_synchronizer_1 = require("./create-composable-state-synchronizer");
describe('composeStateSynchronizers', function () {
    it('should return a function', function () {
        expect.hasAssertions();
        var synchronizer = compose_state_synchronizers_1.composeStateSynchronizers([]);
        expect(synchronizer).toBeInstanceOf(Function);
    });
    it('should throw an error when there is a cycle in the dependencies', function () {
        expect.hasAssertions();
        var synchronizers = [
            {
                stateKey: 'a',
                dependenciesKeys: ['b'],
                synchronizer: jest.fn()
            },
            {
                stateKey: 'b',
                dependenciesKeys: ['a'],
                synchronizer: jest.fn()
            },
        ];
        expect(function () { return compose_state_synchronizers_1.composeStateSynchronizers(synchronizers); }).toThrow('Cycle detected: b->a->b');
    });
    describe('returned state synchronizer', function () {
        var initialState = {
            pageSize: 10,
            recordsCount: 20,
            maxPage: 2,
            currentPage: 1
        };
        var maxPageUpdater = jest.fn(function (state) { return (__assign(__assign({}, state), { maxPage: Math.max(1, Math.ceil(state.recordsCount / state.pageSize)) })); });
        var currentPageUpdater = jest.fn(function (state) { return (__assign(__assign({}, state), { currentPage: Math.min(state.currentPage, state.maxPage) })); });
        var synchronizers = [
            create_composable_state_synchronizer_1.createComposableStateSynchronizer(maxPageUpdater, 'maxPage', [
                'recordsCount',
                'pageSize',
            ]),
            create_composable_state_synchronizer_1.createComposableStateSynchronizer(currentPageUpdater, 'currentPage', [
                'maxPage',
            ]),
        ];
        beforeEach(function () {
            jest.clearAllMocks();
        });
        it('should run necessary synchronizers in correct order when the state changed', function () {
            expect.hasAssertions();
            var synchronizer = compose_state_synchronizers_1.composeStateSynchronizers(synchronizers);
            var newState = __assign(__assign({}, initialState), { recordsCount: 17 });
            var result = synchronizer(newState, initialState);
            expect(maxPageUpdater).toHaveBeenCalledTimes(1);
            expect(currentPageUpdater).not.toHaveBeenCalled();
            expect(result).toStrictEqual(newState);
        });
        it('should propagate the change made by the synchronizers', function () {
            expect.hasAssertions();
            var synchronizer = compose_state_synchronizers_1.composeStateSynchronizers(synchronizers);
            var newState = __assign(__assign({}, initialState), { recordsCount: 28 });
            var result = synchronizer(newState, initialState);
            expect(maxPageUpdater).toHaveBeenCalledTimes(1);
            expect(currentPageUpdater).toHaveBeenCalledTimes(1);
            expect(result).toStrictEqual(__assign(__assign({}, newState), { maxPage: 3 }));
        });
        it('should propagate the change made by the synchronizers (2)', function () {
            expect.hasAssertions();
            var synchronizer = compose_state_synchronizers_1.composeStateSynchronizers(synchronizers);
            var newState = __assign(__assign({}, initialState), { recordsCount: 28, currentPage: 4 });
            var result = synchronizer(newState, initialState);
            expect(maxPageUpdater).toHaveBeenCalledTimes(1);
            expect(currentPageUpdater).toHaveBeenCalledTimes(1);
            expect(result).toStrictEqual(__assign(__assign({}, newState), { maxPage: 3, currentPage: 3 }));
        });
        it('should pass state returned from earlier synchronizer to the later one', function () {
            expect.hasAssertions();
            var synchronizer = compose_state_synchronizers_1.composeStateSynchronizers(synchronizers);
            var newState = __assign(__assign({}, initialState), { recordsCount: 28, currentPage: 4 });
            synchronizer(newState, initialState);
            expect(maxPageUpdater).toHaveBeenCalledWith(newState);
            expect(currentPageUpdater).toHaveBeenCalledWith(maxPageUpdater.mock.results[0].value);
        });
    });
});