ESLint is a static code inspection tool for JavaScript and JSX, which is mainly used to discover potential problems in the code and unify the code style. It not only checks for syntax errors, but also points out non-standard, prone to errors or in compliance with best practices based on configuration rules. Its core functions include: discovering common errors in advance (such as unused variables), unifying the code style, cooperating with the editor's real-time prompts, and supporting automatic fixes of some problems. The steps for use are: install ESLint, create configuration files, select rulesets, run check commands, and use them with the editor plug-in. Coping strategies include: using loose configurations to gradually strengthen rules, closing unwanted rules, and integrating in CI/CD to ensure uniform use of the team. Through reasonable configuration, ESLint can significantly improve code quality and maintenance efficiency.
ESLint is a static code inspection tool for JavaScript and JSX. It is mainly used to discover potential problems in the code and ensure consistency in the code style. Instead of just checking for syntax errors like the compiler, it can point out non-standard, prone to errors or incompatible with best practices based on the ruleset you configure.
Why do you need ESLint?
In team collaboration, different developers may have different coding habits, such as the naming method of variables, whether to use single or double quotes, etc. These differences can lead to confusion in the code style and even cause bugs.
ESLint can:
- Discover common errors in advance (such as unused variables)
- Unify code style and reduce "aesthetic" controversy
- Cooperate with the editor's real-time prompts to improve development efficiency
- Support automatic fixing of some problems (such as via
eslint --fix
)
For example: If you accidentally write code like this:
const name = "John"; console.log(nam); // I've spelled the name here
If ESLint is enabled, you can prompt you that this variable is not defined immediately to help you avoid runtime errors.
How to use ESLint?
Installing and configuring ESLint is not complicated, the basic process is as follows:
Install ESLint:
npm install eslint --save-dev
Create a configuration file
.eslintrc.js
or.eslintrc.json
Select your preferred rule set (such as Airbnb, Standard, etc.) or customize it in the configuration file
Run in the project root directory:
npx eslint .
In conjunction with editor plug-ins (such as the ESLint plug-in for VS Code), errors can be displayed in real time when writing code
You can add scripts to simplify commands, for example:
"scripts": { "lint": "eslint .", "lint:fix": "eslint . --fix" }
This way you can run npm run lint
directly to check the code.
FAQs and Suggestions
What should I do if there are too many rules and too strict?
When you first use ESLint, you may be frightened by a large number of errors. At this time, it is recommended:
- Enable a looser configuration first (such as
eslint:recommended
) - Gradually add stricter rules
- For unwanted rules, set to
"off"
in the configuration file or adjust to"warn"
How to make the team use ESLint uniformly?
- Add ESLint to the project initialization process
- Add ESLint checks to CI/CD (such as GitHub Actions)
- Recommend team members to install editor plug-in to keep local consistency
How to configure different project types?
ESLint supports a variety of environments, such as browser, Node.js, React, Vue, etc. You can enable support for the corresponding environment by configuring the env
field, or you can use plug-ins (such as eslint-plugin-react
) to enhance support for specific frameworks.
Basically that's it. ESLint can be a bit cumbersome at the beginning, but once configured, it can significantly improve code quality and maintenance efficiency.
The above is the detailed content of What is ESLint. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

React itself does not directly manage focus or accessibility, but provides tools to effectively deal with these issues. 1. Use Refs to programmatically manage focus, such as setting element focus through useRef; 2. Use ARIA attributes to improve accessibility, such as defining the structure and state of tab components; 3. Pay attention to keyboard navigation to ensure that the focus logic in components such as modal boxes is clear; 4. Try to use native HTML elements to reduce the workload and error risk of custom implementation; 5. React assists accessibility by controlling the DOM and adding ARIA attributes, but the correct use still depends on developers.

Shallowrenderingtestsacomponentinisolation,withoutchildren,whilefullrenderingincludesallchildcomponents.Shallowrenderingisgoodfortestingacomponent’sownlogicandmarkup,offeringfasterexecutionandisolationfromchildbehavior,butlacksfulllifecycleandDOMinte

StrictMode does not render any visual content in React, but it is very useful during development. Its main function is to help developers identify potential problems, especially those that may cause bugs or unexpected behavior in complex applications. Specifically, it flags unsafe lifecycle methods, recognizes side effects in render functions, and warns about the use of old string refAPI. In addition, it can expose these side effects by intentionally repeating calls to certain functions, thereby prompting developers to move related operations to appropriate locations, such as the useEffect hook. At the same time, it encourages the use of newer ref methods such as useRef or callback ref instead of string ref. To use Stri effectively

Create TypeScript-enabled projects using VueCLI or Vite, which can be quickly initialized through interactive selection features or using templates. Use tags in components to implement type inference with defineComponent, and it is recommended to explicitly declare props and emits types, and use interface or type to define complex structures. It is recommended to explicitly label types when using ref and reactive in setup functions to improve code maintainability and collaboration efficiency.

Server-siderendering(SSR)inNext.jsgeneratesHTMLontheserverforeachrequest,improvingperformanceandSEO.1.SSRisidealfordynamiccontentthatchangesfrequently,suchasuserdashboards.2.ItusesgetServerSidePropstofetchdataperrequestandpassittothecomponent.3.UseSS

WebAssembly(WASM)isagame-changerforfront-enddevelopersseekinghigh-performancewebapplications.1.WASMisabinaryinstructionformatthatrunsatnear-nativespeed,enablinglanguageslikeRust,C ,andGotoexecuteinthebrowser.2.ItcomplementsJavaScriptratherthanreplac

Vite or VueCLI depends on project requirements and development priorities. 1. Startup speed: Vite uses the browser's native ES module loading mechanism, which is extremely fast and cold-start, usually completed within 300ms, while VueCLI uses Webpack to rely on packaging and is slow to start; 2. Configuration complexity: Vite starts with zero configuration, has a rich plug-in ecosystem, which is suitable for modern front-end technology stacks, VueCLI provides comprehensive configuration options, suitable for enterprise-level customization but has high learning costs; 3. Applicable project types: Vite is suitable for small projects, rapid prototype development and projects using Vue3, VueCLI is more suitable for medium and large enterprise projects or projects that need to be compatible with Vue2; 4. Plug-in ecosystem: VueCLI is perfect but has slow updates,

Immutable updates are crucial in React because it ensures that state changes can be detected correctly, triggering component re-rendering and avoiding side effects. Directly modifying state, such as push or assignment, will cause React to be unable to detect changes. The correct way to do this is to create new objects instead of old objects, such as updating an array or object using the expand operator. For nested structures, you need to copy layer by layer and modify only the target part, such as using multiple expansion operators to deal with deep attributes. Common operations include updating array elements with maps, deleting elements with filters, adding elements with slices or expansion. Tool libraries such as Immer can simplify the process, allowing "seemingly" to modify the original state but generate new copies, but increase project complexity. Key tips include each
