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benchmark: add benchmark for NODE_V8_COVERAGE
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bcoe committed Jan 18, 2021
1 parent a8d8ca3 commit c5507d4
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115 changes: 115 additions & 0 deletions benchmark/fixtures/coverage-many-branches.js
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'use strict';

// Exercise coverage of a class. Note, this logic is silly and exists solely
// to generate branch coverage code paths:
class CoveredClass {
constructor(x, y, opts) {
this.x = x;
this.y = y;
// Exercise coverage of nullish coalescing:
this.opts = opts ?? (Math.random() > 0.5 ? {} : undefined);
}
add() {
return this.x + this.y;
}
addSpecial() {
// Exercise coverage of optional chains:
if (this.opts?.special && this.opts?.special?.x && this.opts?.special?.y) {
return this.opts.special.x + this.opts.special.y;
}
return add();
}
mult() {
return this.x * this.y;
}
multSpecial() {
if (this.opts?.special && this.opts?.special?.x && this.opts?.special?.y) {
return this.opts.special.x * this.opts.special.y;
}
return mult();
}
}

// Excercise coverage of functions:
function add(x, y) {
const mt = new CoveredClass(x, y);
return mt.add();
}

function addSpecial(x, y) {
let mt;
if (Math.random() > 0.5) {
mt = new CoveredClass(x, y);
} else {
mt = new CoveredClass(x, y, {
special: {
x: Math.random() * x,
y: Math.random() * y
}
});
}
return mt.addSpecial();
}

function mult(x, y) {
const mt = new CoveredClass(x, y);
return mt.mult();
}

function multSpecial(x, y) {
let mt;
if (Math.random() > 0.5) {
mt = new CoveredClass(x, y);
} else {
mt = new CoveredClass(x, y, {
special: {
x: Math.random() * x,
y: Math.random() * y
}
});
}
return mt.multSpecial();
}

for (let i = 0; i < parseInt(process.env.N); i++) {
const operations = ['add', 'addSpecial', 'mult', 'multSpecial'];
for (const operation of operations) {
// Exercise coverage of switch statements:
switch (operation) {
case 'add':
if (add(Math.random() * 10, Math.random() * 10) > 10) {
// Exercise coverage of ternary operations:
let r = addSpecial(Math.random() * 10, Math.random() * 10) > 10 ?
mult(Math.random() * 10, Math.random() * 10) :
add(Math.random() * 10, Math.random() * 10);
// Exercise && and ||
if (r && Math.random() > 0.5 || Math.random() < 0.5) r++;
}
break;
case 'addSpecial':
if (addSpecial(Math.random() * 10, Math.random() * 10) > 10 &&
add(Math.random() * 10, Math.random() * 10) > 10) {
let r = mult(Math.random() * 10, Math.random() * 10) > 10 ?
add(Math.random() * 10, Math.random() * 10) > 10 :
mult(Math.random() * 10, Math.random() * 10);
if (r && Math.random() > 0.5 || Math.random() < 0.5) r++;
}
break;
case 'mult':
if (mult(Math.random() * 10, Math.random() * 10) > 10) {
let r = multSpecial(Math.random() * 10, Math.random() * 10) > 10 ?
add(Math.random() * 10, Math.random() * 10) :
mult(Math.random() * 10, Math.random() * 10);
if (r && Math.random() > 0.5 || Math.random() < 0.5) r++;
}
break;
case 'multSpecial':
while (multSpecial(Math.random() * 10, Math.random() * 10) < 10) {
mult(Math.random() * 10, Math.random() * 10);
}
break;
default:
break;
}
}
}
32 changes: 32 additions & 0 deletions benchmark/process/coverage.js
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// This benchmark is meant to exercise a grab bag of code paths that would
// be expected to run slower under coverage. To use this benchmark, create an
// alternate node bin that enables coverage and compare it against ./node
'use strict';
const common = require('../common.js');
const bench = common.createBenchmark(main, {
n: [1e5]
});
const path = require('path');
const { randomUUID } = require('crypto');
const { rmSync } = require('fs');
const { spawnSync } = require('child_process');
const tmpdir = require('../../test/common/tmpdir');

const coverageDir = path.join(tmpdir.path, `./cov-${randomUUID()}`);

function main({ n }) {
bench.start();
const result = spawnSync(process.execPath, [
require.resolve('../fixtures/coverage-many-branches'),
], {
env: {
NODE_V8_COVERAGE: coverageDir,
N: n,
}
});
rmSync(coverageDir, { recursive: true, force: true });
if (result.status !== 0) {
throw new Error(result.stderr.toString('utf8'));
}
bench.end(n);
}

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