Files
tools/test/observables/ReadOnlySubject.test.ts
2025-08-16 14:17:46 -04:00

61 lines
2.0 KiB
TypeScript

import {jest, describe, it, expect} from 'bun:test';
import {Subject, ReadOnlySubject} from '../../src/observables';
describe(`A ReadOnlySubject`, () => {
it(`exposes the Subject value`, () => {
const subject = new Subject<string>(`init-value`);
const readOnlySubject = new ReadOnlySubject(subject);
expect(readOnlySubject.value).toBe(`init-value`);
});
it(`updates the ReadOnlySubject value when set`, () => {
const subject = new Subject<string>('init-value');
const readOnlySubject = new ReadOnlySubject(subject);
subject.value = 'some thing';
expect(readOnlySubject.value).toBe('some thing');
});
it(`notifies subcribers when subscribing`, () => {
const subject = new Subject<string>('init-value');
const readOnlySubject = new ReadOnlySubject(subject);
const listener = jest.fn() as (value: string) => void;
readOnlySubject.subscribe(listener);
expect(listener).toHaveBeenCalledWith('init-value');
});
it(`notifies subcribers when value changes`, () => {
const subject = new Subject<string>('init-value');
const readOnlySubject = new ReadOnlySubject(subject);
const listener = jest.fn() as (value: string) => void;
readOnlySubject.subscribe(listener);
subject.value = 'some thing';
expect(listener).toHaveBeenCalledWith('some thing');
});
it(`notifies all subcribers when value changes`, () => {
const subject = new Subject<string>('init-value');
const readOnlySubject = new ReadOnlySubject(subject);
const listener1 = jest.fn() as (value: string) => void;
const listener2 = jest.fn() as (value: string) => void;
const listener3 = jest.fn() as (value: string) => void;
readOnlySubject.subscribe(listener1);
readOnlySubject.subscribe(listener2);
readOnlySubject.subscribe(listener3);
subject.value = 'some thing';
expect(listener1).toHaveBeenCalledWith('some thing');
expect(listener2).toHaveBeenCalledWith('some thing');
expect(listener3).toHaveBeenCalledWith('some thing');
});
});