What is @types/eslint?
@types/eslint provides TypeScript type definitions for the ESLint library, enabling developers to use ESLint with TypeScript more effectively. It helps in ensuring type safety and better autocompletion in IDEs.
What are @types/eslint's main functionalities?
Linting Configuration
This feature allows you to define and configure ESLint settings using TypeScript. The code sample demonstrates how to set up an ESLint configuration object with various settings like environment, parser, and rules.
const eslintConfig: ESLint.Config = {
env: {
browser: true,
es2021: true
},
extends: [
'eslint:recommended',
'plugin:@typescript-eslint/recommended'
],
parser: '@typescript-eslint/parser',
parserOptions: {
ecmaVersion: 12,
sourceType: 'module'
},
rules: {
'no-unused-vars': 'warn',
'semi': ['error', 'always']
}
};
Linting Programmatically
This feature allows you to run ESLint programmatically using TypeScript. The code sample shows how to create an ESLint instance and lint files, then output the linting results.
import { ESLint } from 'eslint';
const eslint = new ESLint({
baseConfig: {
extends: ['eslint:recommended']
}
});
async function lintFiles(files: string[]) {
const results = await eslint.lintFiles(files);
results.forEach(result => {
console.log(result.filePath);
result.messages.forEach(msg => console.log(`${msg.line}:${msg.column} ${msg.message}`));
});
}
lintFiles(['src/**/*.ts']);
Custom ESLint Rules
This feature allows you to define custom ESLint rules using TypeScript. The code sample demonstrates how to create a rule that disallows the use of console statements.
import { Rule } from 'eslint';
const noConsoleRule: Rule.RuleModule = {
create(context) {
return {
CallExpression(node) {
if (node.callee.type === 'MemberExpression' && node.callee.object.name === 'console') {
context.report({ node, message: 'Unexpected console statement.' });
}
}
};
}
};
export default noConsoleRule;
Other packages similar to @types/eslint
@typescript-eslint/eslint-plugin
This package provides a set of ESLint rules that are specific to TypeScript. It works in conjunction with @typescript-eslint/parser to lint TypeScript code. Compared to @types/eslint, it focuses more on providing TypeScript-specific linting rules rather than type definitions.
tslint
TSLint is an extensible static analysis tool that checks TypeScript code for readability, maintainability, and functionality errors. While TSLint is deprecated in favor of ESLint with TypeScript support, it served a similar purpose to @types/eslint by providing linting capabilities for TypeScript.
eslint-config-airbnb-typescript
This package provides a TypeScript configuration for ESLint based on Airbnb's style guide. It is a shareable ESLint configuration that includes TypeScript support, making it easier to set up ESLint with TypeScript. Unlike @types/eslint, it focuses on providing a pre-configured set of rules rather than type definitions.