Brian GoughandCopybot
d24f37d3a4
add latexmk `-time` option to clsi and record performance logs GitOrigin-RevId: 467473859359913da73f83e10b63b45603ea175c
86 lines
3.2 KiB
JavaScript
86 lines
3.2 KiB
JavaScript
const { expect } = require('chai')
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const { sampleByHash } = require('../../../app/js/StatsManager')
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describe('StatsManager', function () {
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describe('sampleByHash', function () {
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it('should always return false for a sample percentage of 0', function () {
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for (let i = 0; i < 100; i++) {
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const key = `test-key-${i}`
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expect(sampleByHash(key, 0), `key ${key} should be false`).to.be.false
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}
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})
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it('should always return false for a negative sample percentage', function () {
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for (let i = 0; i < 100; i++) {
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const key = `test-key-${i}`
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expect(sampleByHash(key, -10), `key ${key} should be false`).to.be.false
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}
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})
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it('should always return true for a sample percentage of 100', function () {
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// This isn't strictly true, if the hash is exactly 0xffffffff, then the percentile is 100
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// and 100 < 100 is false. But the chances of that are 1 in 4 billion.
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for (let i = 0; i < 100; i++) {
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const key = `test-key-${i}`
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expect(sampleByHash(key, 100), `key ${key} should be true`).to.be.true
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}
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})
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it('should return the expected number of results for a sample percentage of 75', function () {
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// This isn't strictly true, if the hash is exactly 0xffffffff, then the percentile is 100
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// and 100 < 100 is false. But the chances of that are 1 in 4 billion.
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let count = 0
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for (let i = 0; i < 100; i++) {
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const key = `test-key-${i}`
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count += sampleByHash(key, 75) ? 1 : 0
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}
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// Actual result is 74, it's deterministic but the test allows the algorithm to change
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expect(count).to.be.within(70, 80)
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})
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it('should return true when the hash is within the sample percentage', function () {
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// The MD5 hash of 'test-key-in' gives a percentile of 13
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const key = 'test-key-in'
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const percentage = 40
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expect(sampleByHash(key, percentage)).to.be.true
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})
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it('should return false when the hash is outside the sample percentage', function () {
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// The MD5 hash of 'test-key-outer' gives a percentile of 47
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const key = 'test-key-outer'
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const percentage = 40
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expect(sampleByHash(key, percentage)).to.be.false
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})
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it('should produce consistent results for the same key', function () {
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const key = 'consistent-key'
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const percentage = 50
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const result1 = sampleByHash(key, percentage)
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const result2 = sampleByHash(key, percentage)
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expect(result1).to.equal(result2)
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})
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it('should handle different keys correctly', function () {
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// MD5('key1') => percentile 76
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// MD5('key2') => percentile 47
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expect(sampleByHash('key1', 80)).to.be.true
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expect(sampleByHash('key1', 70)).to.be.false
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expect(sampleByHash('key2', 50)).to.be.true
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expect(sampleByHash('key2', 40)).to.be.false
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})
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it('should be monotonic with respect to percentage', function () {
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const key = 'test-key'
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const percentile = 32
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for (let i = 0; i <= 100; i++) {
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const result = sampleByHash(key, i)
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if (i <= percentile) {
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expect(result, `percentage ${i} should be false`).to.be.false
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} else {
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expect(result, `percentage ${i} should be true`).to.be.true
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}
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}
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})
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})
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})
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