rdesign/frontend/node_modules/signal-polyfill/tests/Signal/state.test.ts

58 lines
1.4 KiB
TypeScript

import {describe, expect, it} from 'vitest';
import {Signal} from '../../src/wrapper.js';
describe('Signal.State', () => {
it('should work', () => {
const stateSignal = new Signal.State(0);
expect(stateSignal.get()).toEqual(0);
stateSignal.set(10);
expect(stateSignal.get()).toEqual(10);
});
describe('Comparison semantics', () => {
it('should cache State by Object.is', () => {
const state = new Signal.State(NaN);
let calls = 0;
const computed = new Signal.Computed(() => {
calls++;
return state.get();
});
expect(calls).toBe(0);
expect(computed.get()).toBe(NaN);
expect(calls).toBe(1);
state.set(NaN);
expect(computed.get()).toBe(NaN);
expect(calls).toBe(1);
});
it('applies custom equality in State', () => {
let ecalls = 0;
const state = new Signal.State(1, {
equals() {
ecalls++;
return false;
},
});
let calls = 0;
const computed = new Signal.Computed(() => {
calls++;
return state.get();
});
expect(calls).toBe(0);
expect(ecalls).toBe(0);
expect(computed.get()).toBe(1);
expect(ecalls).toBe(0);
expect(calls).toBe(1);
state.set(1);
expect(computed.get()).toBe(1);
expect(ecalls).toBe(1);
expect(calls).toBe(2);
});
});
});