Best JavaScript code snippet using jest
CopyrightUtils.js
Source: CopyrightUtils.js
...107 !micromatch.isMatch(file, excludePatterns) &&108 existsSync(file) &&109 !lstatSync(file).isDirectory() &&110 !isBinaryFileSync(file) &&111 needsCopyrightHeader(copyrightText, file),112 );113};114export const getFilesWithCopyrightHeader = ({115 extensions = [],116 /* micromatch glob patterns */117 excludePatterns = [],118 copyrightText,119}) => {120 const files = execSync('git ls-files', { encoding: 'utf-8' })121 .trim()122 .split('\n');123 const includePatterns = getIncludedPatterns({ extensions });124 return files.filter(125 (file) =>...
check-license-headers.js
Source: check-license-headers.js
...109 // Any file with an extension110 /\.[^/]+$/,111];112const COPYRIGHT_HEADER_RE = /Copyright (\(c\))? [0-9]{4}, (s|S)alesforce.com, inc./;113function needsCopyrightHeader(file) {114 const contents = getFileContents(file);115 return contents.trim().length > 0 && !COPYRIGHT_HEADER_RE.test(contents);116}117function check() {118 const allFiles = execSync('git ls-files', { encoding: 'utf-8' }).trim().split('\n');119 const invalidFiles = allFiles.filter(120 (file) =>121 INCLUDED_PATTERNS.some((pattern) => pattern.test(file)) &&122 !IGNORED_PATTERNS.some((pattern) => pattern.test(file)) &&123 !isDirectory(file) &&124 !isBinaryFileSync(file) &&125 needsCopyrightHeader(file)126 );127 if (invalidFiles.length > 0) {128 console.log(`Salesforce copyright header check failed for the following files:129 ${invalidFiles.join('\n ')}130Please include the header or add an exception for the file in \`scripts/checkCopyrightHeaders.js\``);131 process.exit(1);132 }133}...
checkLicenseHeaders.js
Source: checkLicenseHeaders.js
...105 // Any file with an extension106 /\.[^/]+$/,107];108const COPYRIGHT_HEADER_RE = /Copyright (\(c\))? [0-9]{4}, (s|S)alesforce.com, inc./;109function needsCopyrightHeader(file) {110 const contents = getFileContents(file);111 return contents.trim().length > 0 && !COPYRIGHT_HEADER_RE.test(contents);112}113function check() {114 const allFiles = execSync('git ls-files', {encoding: 'utf-8'})115 .trim()116 .split('\n');117 const invalidFiles = allFiles.filter(118 file =>119 INCLUDED_PATTERNS.some(pattern => pattern.test(file)) &&120 !IGNORED_PATTERNS.some(pattern => pattern.test(file)) &&121 !isDirectory(file) &&122 !isBinaryFileSync(file) &&123 needsCopyrightHeader(file)124 );125 if (invalidFiles.length > 0) {126 console.log(`Salesforce copyright header check failed for the following files:127 ${invalidFiles.join('\n ')}128Please include the header or blacklist the files in \`scripts/checkCopyrightHeaders.js\``);129 process.exit(1);130 }131}...
checkCopyrightHeaders.js
Source: checkCopyrightHeaders.js
...104 /\.[^/]+$/,105];106const COPYRIGHT_HEADER =107 'Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.';108function needsCopyrightHeader(file) {109 const contents = getFileContents(file);110 return contents.trim().length > 0 && !contents.includes(COPYRIGHT_HEADER);111}112function check() {113 const allFiles = execSync('git ls-files', {encoding: 'utf-8'})114 .trim()115 .split('\n');116 const invalidFiles = allFiles.filter(117 file =>118 INCLUDED_PATTERNS.some(pattern => pattern.test(file)) &&119 !IGNORED_PATTERNS.some(pattern => pattern.test(file)) &&120 !isDirectory(file) &&121 !isBinaryFileSync(file) &&122 needsCopyrightHeader(file)123 );124 if (invalidFiles.length > 0) {125 console.log(`Facebook copyright header check failed for the following files:126 ${invalidFiles.join('\n ')}127Please include the header or blacklist the files in \`scripts/checkCopyrightHeaders.js\``);128 process.exit(1);129 }130}...
How to test if a method returns an array of a class in Jest
How do node_modules packages read config files in the project root?
Jest: how to mock console when it is used by a third-party-library?
ERESOLVE unable to resolve dependency tree while installing a pacakge
Testing arguments with toBeCalledWith() in Jest
Is there assertCountEqual equivalent in javascript unittests jest library?
NodeJS: NOT able to set PERCY_TOKEN via package script with start-server-and-test
Jest: How to consume result of jest.genMockFromModule
How To Reset Manual Mocks In Jest
How to move '__mocks__' folder in Jest to /test?
Since Jest tests are runtime tests, they only have access to runtime information. You're trying to use a type, which is compile-time information. TypeScript should already be doing the type aspect of this for you. (More on that in a moment.)
The fact the tests only have access to runtime information has a couple of ramifications:
If it's valid for getAll
to return an empty array (because there aren't any entities to get), the test cannot tell you whether the array would have had Entity
elements in it if it hadn't been empty. All it can tell you is it got an array.
In the non-empty case, you have to check every element of the array to see if it's an Entity
. You've said Entity
is a class, not just a type, so that's possible. I'm not a user of Jest (I should be), but it doesn't seem to have a test specifically for this; it does have toBeTruthy
, though, and we can use every
to tell us if every element is an Entity
:
it('should return an array of Entity class', async () => {
const all = await service.getAll()
expect(all.every(e => e instanceof Entity)).toBeTruthy();
});
Beware, though, that all calls to every
on an empty array return true
, so again, that empty array issue raises its head.
If your Jest tests are written in TypeScript, you can improve on that by ensuring TypeScript tests the compile-time type of getAll
's return value:
it('should return an array of Entity class', async () => {
const all: Entity[] = await service.getAll()
// ^^^^^^^^^^
expect(all.every(e => e instanceof Entity)).toBeTruthy();
});
TypeScript will complain about that assignment at compile time if it's not valid, and Jest will complain at runtime if it sees an array containing a non-Entity
object.
But jonrsharpe has a good point: This test may not be useful vs. testing for specific values that should be there.
Check out the latest blogs from LambdaTest on this topic:
Node js has become one of the most popular frameworks in JavaScript today. Used by millions of developers, to develop thousands of project, node js is being extensively used. The more you develop, the better the testing you require to have a smooth, seamless application. This article shares the best practices for the testing node.in 2019, to deliver a robust web application or website.
Storybook offers a clean-room setting for isolating component testing. No matter how complex a component is, stories make it simple to explore it in all of its permutations. Before we discuss the Storybook testing in any browser, let us try and understand the fundamentals related to the Storybook framework and how it simplifies how we build UI components.
Quality Assurance (QA) is at the point of inflection and it is an exciting time to be in the field of QA as advanced digital technologies are influencing QA practices. As per a press release by Gartner, The encouraging part is that IT and automation will play a major role in transformation as the IT industry will spend close to $3.87 trillion in 2020, up from $3.76 trillion in 2019.
This article is a part of our Content Hub. For more in-depth resources, check out our content hub on WebDriverIO Tutorial and Selenium JavaScript Tutorial.
Having a strategy or plan can be the key to unlocking many successes, this is true to most contexts in life whether that be sport, business, education, and much more. The same is true for any company or organisation that delivers software/application solutions to their end users/customers. If you narrow that down even further from Engineering to Agile and then even to Testing or Quality Engineering, then strategy and planning is key at every level.
LambdaTest’s Jest Testing Tutorial covers step-by-step guides around Jest with code examples to help you be proficient with the Jest framework. The Jest tutorial has chapters to help you learn right from the basics of Jest framework to code-based tutorials around testing react apps with Jest, perform snapshot testing, import ES modules and more.
|<p>it('check_object_of_Car', () => {</p><p>
expect(newCar()).toBeInstanceOf(Car);</p><p>
});</p>|
| :- |
Get 100 minutes of automation test minutes FREE!!