updux/src/mutations.test.ts

import { test, expect } from 'vitest';

import Updux, { createAction } from './index.js';

test('set a mutation', () => {
    const dux = new Updux({
        initial: 'potato',
        actions: {
            foo: (x) => ({ x }),
            bar: 0,
        },
    });

    let didIt = false;

    dux.addMutation(dux.actions.foo, (payload, action) => () => {
        didIt = true;
        expect(payload).toEqual({ x: 'hello ' });
        expect(action).toEqual(dux.actions.foo('hello '));
        return payload.x + action.type;
    });

    const result = dux.reducer(undefined, dux.actions.foo('hello '));
    expect(didIt).toBeTruthy();
    expect(result).toEqual('hello foo');
});

test('catch-all mutation', () => {
    const dux = new Updux({
        initial: '',
    });

    dux.addMutation(
        () => true,
        (payload, action) => () => 'got it',
    );

    expect(dux.reducer(undefined, { type: 'foo' })).toEqual('got it');
});

test('default mutation', () => {
    const dux = new Updux({
        initial: '',
        actions: {
            foo: 0,
        },
    });

    dux.addMutation(dux.actions.foo, () => () => 'got it');

    dux.addDefaultMutation((_payload, action) => () => action.type);

    expect(dux.reducer(undefined, { type: 'foo' })).toEqual('got it');
    expect(dux.reducer(undefined, { type: 'bar' })).toEqual('bar');
});

test('mutation of a subdux', () => {
    const baz = createAction('baz');
    const noop = createAction('noop');
    const stopit = createAction('stopit');

    const bar = new Updux({
        initial: 0,
        actions: {
            baz,
            stopit,
        },
    });
    bar.addMutation(baz, () => () => 1);
    bar.addMutation(stopit, () => () => 2);

    const foo = new Updux({
        subduxes: { bar },
    });
    foo.addMutation(stopit, () => (state) => state, true);

    expect(foo.reducer(undefined, noop())).toHaveProperty('bar', 0);
    expect(foo.reducer(undefined, baz())).toHaveProperty('bar', 1);
    expect(foo.reducer(undefined, stopit())).toHaveProperty('bar', 0);
});