puppeteer/test/golden-utils.js
Andrey Lushnikov e6725e15af
tests: drop jasmine test runner (#1519)
This patch introduces a tiny test runner to run puppeteer tests.
The test runner is self-container and allows parallel (wrt IO) test execution.
It will also allow us to split tests into multiple files if necessary.

Comparing to the jasmine, the testrunner supports parallel execution, properly
handles "unhandled promise rejection" event and signals.

Comparing to ava/jest, the testrunner doesn't run multiple node processes,
which makes it simpler but sufficient for our goals.
2017-12-07 16:37:22 -08:00

145 lines
4.7 KiB
JavaScript

/**
* Copyright 2017 Google Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
const path = require('path');
const fs = require('fs');
const Diff = require('text-diff');
const mime = require('mime');
const PNG = require('pngjs').PNG;
const pixelmatch = require('pixelmatch');
module.exports = {compare};
const GoldenComparators = {
'image/png': compareImages,
'text/plain': compareText
};
/**
* @param {?Object} actualBuffer
* @param {!Buffer} expectedBuffer
* @return {?{diff: (!Object:undefined), errorMessage: (string|undefined)}}
*/
function compareImages(actualBuffer, expectedBuffer) {
if (!actualBuffer || !(actualBuffer instanceof Buffer))
return { errorMessage: 'Actual result should be Buffer.' };
const actual = PNG.sync.read(actualBuffer);
const expected = PNG.sync.read(expectedBuffer);
if (expected.width !== actual.width || expected.height !== actual.height) {
return {
errorMessage: `Sizes differ: expected image ${expected.width}px X ${expected.height}px, but got ${actual.width}px X ${actual.height}px. `
};
}
const diff = new PNG({width: expected.width, height: expected.height});
const count = pixelmatch(expected.data, actual.data, diff.data, expected.width, expected.height, {threshold: 0.1});
return count > 0 ? { diff: PNG.sync.write(diff) } : null;
}
/**
* @param {?Object} actual
* @param {!Buffer} expectedBuffer
* @return {?{diff: (!Object:undefined), errorMessage: (string|undefined)}}
*/
function compareText(actual, expectedBuffer) {
if (typeof actual !== 'string')
return { errorMessage: 'Actual result should be string' };
const expected = expectedBuffer.toString('utf-8');
if (expected === actual)
return null;
const diff = new Diff();
const result = diff.main(expected, actual);
diff.cleanupSemantic(result);
let html = diff.prettyHtml(result);
const diffStylePath = path.join(__dirname, 'diffstyle.css');
html = `<link rel="stylesheet" href="file://${diffStylePath}">` + html;
return {
diff: html,
diffExtension: '.html'
};
}
/**
* @param {?Object} actual
* @param {string} goldenName
* @return {!{pass: boolean, message: (undefined|string)}}
*/
function compare(goldenPath, outputPath, actual, goldenName) {
goldenPath = path.normalize(goldenPath);
outputPath = path.normalize(outputPath);
const expectedPath = path.join(goldenPath, goldenName);
const actualPath = path.join(outputPath, goldenName);
const messageSuffix = 'Output is saved in "' + path.basename(outputPath + '" directory');
if (!fs.existsSync(expectedPath)) {
ensureOutputDir();
fs.writeFileSync(actualPath, actual);
return {
pass: false,
message: goldenName + ' is missing in golden results. ' + messageSuffix
};
}
const expected = fs.readFileSync(expectedPath);
const comparator = GoldenComparators[mime.lookup(goldenName)];
if (!comparator) {
return {
pass: false,
message: 'Failed to find comparator with type ' + mime.lookup(goldenName) + ': ' + goldenName
};
}
const result = comparator(actual, expected);
if (!result)
return { pass: true };
ensureOutputDir();
if (goldenPath === outputPath) {
fs.writeFileSync(addSuffix(actualPath, '-actual'), actual);
} else {
fs.writeFileSync(actualPath, actual);
// Copy expected to the output/ folder for convenience.
fs.writeFileSync(addSuffix(actualPath, '-expected'), expected);
}
if (result.diff) {
const diffPath = addSuffix(actualPath, '-diff', result.diffExtension);
fs.writeFileSync(diffPath, result.diff);
}
let message = goldenName + ' mismatch!';
if (result.errorMessage)
message += ' ' + result.errorMessage;
return {
pass: false,
message: message + ' ' + messageSuffix
};
function ensureOutputDir() {
if (!fs.existsSync(outputPath))
fs.mkdirSync(outputPath);
}
}
/**
* @param {string} filePath
* @param {string} suffix
* @param {string=} customExtension
* @return {string}
*/
function addSuffix(filePath, suffix, customExtension) {
const dirname = path.dirname(filePath);
const ext = path.extname(filePath);
const name = path.basename(filePath, ext);
return path.join(dirname, name + suffix + (customExtension || ext));
}