45 lines
996 B
JavaScript
45 lines
996 B
JavaScript
// @flow strict-local
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import assert from 'assert';
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import sinon from 'sinon';
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import throttle from '../src/throttle';
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describe('throttle', () => {
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it("doesn't invoke a function more than once in a given interval", () => {
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let spy = sinon.spy();
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let throttled = throttle(spy, 100);
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throttled(1);
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throttled(2);
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throttled(3);
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assert(spy.calledOnceWithExactly(1));
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});
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it('calls the underlying function again once the interval has passed', () => {
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let time = sinon.useFakeTimers();
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let spy = sinon.spy();
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let throttled = throttle(spy, 100);
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throttled(1);
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throttled(2);
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throttled(3);
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time.tick(100);
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throttled(4);
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assert.deepEqual(spy.args, [[1], [4]]);
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time.restore();
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});
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it('preserves the `this` when throttled functions are invoked', () => {
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let result;
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let throttled = throttle(function () {
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result = this.bar;
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}, 100);
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throttled.call({bar: 'baz'});
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assert(result === 'baz');
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});
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});
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