87 lines
2.1 KiB
JavaScript
87 lines
2.1 KiB
JavaScript
const { prop } = require('../lib/index.js');
|
|
|
|
describe('A property', () => {
|
|
it('returns its initialized value', () => {
|
|
const a = prop(true);
|
|
expect(a()).toEqual(true);
|
|
});
|
|
|
|
it('returns its set value', () => {
|
|
const a = prop();
|
|
expect(a()).toEqual(undefined);
|
|
expect(a(true)).toEqual(true);
|
|
});
|
|
|
|
it('returns notifies dependents of updates', () => {
|
|
let runCount = 0;
|
|
let currentValue = 1;
|
|
const a = prop();
|
|
a.subscribe(val => {
|
|
runCount += 1;
|
|
expect(val).toEqual(currentValue);
|
|
});
|
|
expect(a(1)).toEqual(1);
|
|
expect(runCount).toEqual(1);
|
|
expect(a(1)).toEqual(1);
|
|
expect(runCount).toEqual(1);
|
|
currentValue = 2;
|
|
expect(a(2)).toEqual(2);
|
|
expect(runCount).toEqual(2);
|
|
expect(a(2)).toEqual(2);
|
|
expect(runCount).toEqual(2);
|
|
currentValue = 1;
|
|
expect(a(1)).toEqual(1);
|
|
expect(runCount).toEqual(3);
|
|
expect(a(1)).toEqual(1);
|
|
expect(runCount).toEqual(3);
|
|
});
|
|
|
|
it('honors cancelled subscriptions', () => {
|
|
let runCount = 0;
|
|
let currentValue = 1;
|
|
const a = prop();
|
|
const cancelSubscription = a.subscribe(val => {
|
|
runCount += 1;
|
|
expect(val).toEqual(currentValue);
|
|
});
|
|
const cancelSubscription2 = a.subscribe(val => {
|
|
runCount += 1;
|
|
expect(val).toEqual(currentValue);
|
|
});
|
|
expect(a(1)).toEqual(1);
|
|
expect(runCount).toEqual(2);
|
|
expect(a(1)).toEqual(1);
|
|
expect(runCount).toEqual(2);
|
|
expect(cancelSubscription()).toEqual(1);
|
|
currentValue = 3;
|
|
expect(a(3)).toEqual(3);
|
|
expect(runCount).toEqual(3);
|
|
expect(cancelSubscription2()).toEqual(0);
|
|
currentValue = 4;
|
|
expect(a(4)).toEqual(4);
|
|
expect(runCount).toEqual(3);
|
|
});
|
|
|
|
it('uses a comparator', () => {
|
|
function setEquals(a, b) {
|
|
return (
|
|
a instanceof Set &&
|
|
b instanceof Set &&
|
|
[...a].reduce((acc, d) => acc && b.has(d), true) &&
|
|
[...b].reduce((acc, d) => acc && a.has(d), true)
|
|
);
|
|
}
|
|
|
|
let runCount = 0;
|
|
|
|
const a = prop(new Set([1, 2]), setEquals);
|
|
a.subscribe(() => (runCount += 1));
|
|
expect([...a()]).toEqual([1, 2]);
|
|
expect(runCount).toEqual(0);
|
|
expect([...a(new Set([2, 1]))]).toEqual([1, 2]);
|
|
expect(runCount).toEqual(0);
|
|
expect([...a(new Set([3, 2, 1]))]).toEqual([3, 2, 1]);
|
|
expect(runCount).toEqual(1);
|
|
});
|
|
});
|