v8/tools/clusterfuzz/js_fuzzer/test/helpers.js
Michael Achenbach 320d98709f Open source js-fuzzer
This is a JavaScript fuzzer originally authored by Oliver Chang. It
is a mutation based fuzzer using Babel code transformations. For more
information see the included README.md.

The original code was altered:
- Add new V8 copyright headers.
- Make the test expectation generator aware of the headers.
- Fix file endings for presubmit checks.
- Fix `npm test` on fresh checkout with a new fake DB.
- Make test skipping work with new v8/tools location.
- OWNERS file.
- New title section in README.md.

No-Try: true
Bug: chromium:1109770
Change-Id: Ie71752c0a37491a50500c49060a3c526716ef933
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2320330
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69164}
2020-07-31 11:34:39 +00:00

76 lines
2.0 KiB
JavaScript

// Copyright 2020 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
/**
* @fileoverview Test helpers.
*/
'use strict';
const assert = require('assert');
const path = require('path');
const fs = require('fs');
const sourceHelpers = require('../source_helpers.js');
const BASE_DIR = path.join(path.dirname(__dirname), 'test_data');
const DB_DIR = path.join(BASE_DIR, 'fake_db');
const HEADER = `// Copyright 2020 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
`;
/**
* Create a function that returns one of `probs` when called. It rotates
* through the values. Useful to replace `random.random()` in tests using
* the probabilities that trigger different interesting cases.
*/
function cycleProbabilitiesFun(probs) {
let index = 0;
return () => {
index = index % probs.length;
return probs[index++];
};
}
/**
* Replace Math.random with a deterministic pseudo-random function.
*/
function deterministicRandom(sandbox) {
let seed = 1;
function random() {
const x = Math.sin(seed++) * 10000;
return x - Math.floor(x);
}
sandbox.stub(Math, 'random').callsFake(() => { return random(); });
}
function loadTestData(relPath) {
return sourceHelpers.loadSource(BASE_DIR, relPath);
}
function assertExpectedResult(expectedPath, result) {
const absPath = path.join(BASE_DIR, expectedPath);
if (process.env.GENERATE) {
fs.writeFileSync(absPath, HEADER + result.trim() + '\n');
return;
}
// Omit copyright header when comparing files.
const expected = fs.readFileSync(absPath, 'utf-8').trim().split('\n');
expected.splice(0, 4);
assert.strictEqual(expected.join('\n'), result.trim());
}
module.exports = {
BASE_DIR: BASE_DIR,
DB_DIR: DB_DIR,
assertExpectedResult: assertExpectedResult,
cycleProbabilitiesFun: cycleProbabilitiesFun,
deterministicRandom: deterministicRandom,
loadTestData: loadTestData,
}