67 lines
2.3 KiB
JavaScript
67 lines
2.3 KiB
JavaScript
const assert = require('assert');
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const TokenBucket = require('../../lib/util/token-bucket').TokenBucket;
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describe('TokenBucket', () => {
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describe('#throttle', () => {
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let bucket;
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beforeEach(() => {
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bucket = new TokenBucket(5, 5);
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});
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it('consumes capacity and then throttles', () => {
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assert(!bucket.throttle(), 'should not be empty yet');
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assert(!bucket.throttle(), 'should not be empty yet');
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assert(!bucket.throttle(), 'should not be empty yet');
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assert(!bucket.throttle(), 'should not be empty yet');
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assert(!bucket.throttle(), 'should not be empty yet');
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assert(bucket.throttle(), 'should be empty now');
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});
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it('refills tokens', () => {
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bucket.count = 0;
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const oldRefill = bucket.lastRefill = Date.now() - 1000;
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assert(!bucket.throttle(), 'should have refilled');
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assert(bucket.lastRefill >= oldRefill + 1000, 'should have updated lastRefill');
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});
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it('refills at most {capacity} tokens', () => {
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bucket.count = 0;
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bucket.lastRefill = Date.now() - 10000;
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bucket.throttle();
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assert.strictEqual(bucket.count, 4);
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});
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it('does a partial refill', () => {
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bucket.count = 0;
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bucket.lastRefill = Date.now() - 400;
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bucket.throttle();
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assert.strictEqual(bucket.count, 1);
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});
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it('skips refilling if delta = 0', () => {
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bucket.count = 0;
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const oldRefill = bucket.lastRefill;
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bucket.throttle();
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assert.strictEqual(bucket.count, 0);
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assert.strictEqual(bucket.lastRefill, oldRefill);
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});
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it('handles fractional refill rates', () => {
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bucket = new TokenBucket(5, 0.1);
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bucket.count = 0;
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assert(bucket.throttle());
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bucket.lastRefill = Date.now() - 10000;
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assert(!bucket.throttle());
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assert.strictEqual(bucket.count, 0);
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});
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it('handles infinite refill rate and capacity', () => {
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bucket = new TokenBucket(Infinity, Infinity);
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for (let i = 0; i < 100; i++) {
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assert(!bucket.throttle(), 'should not throttle');
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}
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});
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});
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});
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