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@typescript-eslint/parser
Advanced tools
An ESLint custom parser which leverages TypeScript ESTree
The @typescript-eslint/parser is an ESLint parser that allows for the analysis and linting of TypeScript code. It is part of the TypeScript-ESLint project, which aims to bring ESLint's powerful static analysis capabilities to TypeScript codebases. The parser converts TypeScript source code into an ESTree-compatible form so that it can be used by ESLint for linting and other code analysis tasks.
Parsing TypeScript code
This feature allows the parser to read TypeScript files and produce an abstract syntax tree (AST) that is compatible with ESLint, enabling it to understand and lint TypeScript syntax.
const { ESLint } = require('eslint');
async function main() {
const eslint = new ESLint({
parser: '@typescript-eslint/parser',
parserOptions: {
ecmaVersion: 2020,
sourceType: 'module',
project: './tsconfig.json'
}
});
const results = await eslint.lintFiles(['src/**/*.ts']);
// Handle the results
}
main();
Integration with ESLint rules
The parser can be used in conjunction with ESLint rules, including those specifically designed for TypeScript, to enforce code quality and style guidelines.
module.exports = {
parser: '@typescript-eslint/parser',
extends: [
'plugin:@typescript-eslint/recommended'
],
rules: {
'@typescript-eslint/no-unused-vars': 'error',
'@typescript-eslint/explicit-function-return-type': 'warn'
}
};
babel-eslint is an ESLint parser that allows you to lint all valid Babel code with ESLint. While it is not specifically designed for TypeScript, it can be used to lint code that uses Babel for transpilation, including TypeScript when used with the appropriate Babel plugins.
This is a deprecated package that was used to provide ESLint rules for TypeScript before the TypeScript-ESLint project was created. It has been replaced by the @typescript-eslint/parser and typescript-eslint/eslint-plugin packages.
An ESLint custom parser which leverages TypeScript ESTree to allow for ESLint to lint TypeScript source code.
npm install --save-dev @typescript-eslint/parser
In your ESLint configuration file, set the parser
property:
{
"parser": "@typescript-eslint/parser"
}
There is sometimes an incorrect assumption that the parser itself is what does everything necessary to facilitate the use of ESLint with TypeScript. In actuality, it is the combination of the parser and one or more plugins which allow you to maximize your usage of ESLint with TypeScript.
For example, once this parser successfully produces an AST for the TypeScript source code, it might well contain some information which simply does not exist in a standard JavaScript context, such as the data for a TypeScript-specific construct, like an interface
.
The core rules built into ESLint, such as indent
have no knowledge of such constructs, so it is impossible to expect them to work out of the box with them.
Instead, you also need to make use of one more plugins which will add or extend rules with TypeScript-specific features.
By far the most common case will be installing the @typescript-eslint/eslint-plugin plugin, but there are also other relevant options available such a @typescript-eslint/eslint-plugin-tslint.
The following additional configuration options are available by specifying them in parserOptions
in your ESLint configuration file.
jsx
- default false
. Enable parsing JSX when true
. More details can be found here.
false
on *.ts
files regardless of this option.true
on *.tsx
files regardless of this option.useJSXTextNode
- default true
. Please set false
if you use this parser on ESLint v4. If this is false
, the parser creates the AST of JSX texts as the legacy style.
{
"parser": "@typescript-eslint/parser",
"parserOptions": {
"jsx": true,
"useJSXTextNode": true
}
}
We will always endeavor to support the latest stable version of TypeScript.
The version of TypeScript currently supported by this parser is ~3.2.1
. This is reflected in the devDependency
requirement within the package.json file, and it is what the tests will be run against. We have an open peerDependency
requirement in order to allow for experimentation on newer/beta versions of TypeScript.
If you use a non-supported version of TypeScript, the parser will log a warning to the console.
Please ensure that you are using a supported version before submitting any issues/bug reports.
Please check the current list of open and known issues and ensure the issue has not been reported before. When creating a new issue provide as much information about your environment as possible. This includes:
@typescript-eslint/parser
versionWe have a very flexible way of running integration tests which connects all of the moving parts of the usage of this parser in the ESLint ecosystem.
We run each test within its own docker container, and so each one has complete autonomy over what dependencies/plugins are installed and what versions are used. This also has the benefit of not bloating the package.json
and node_modules
of the parser project itself.
If you are going to submit an issue related to the usage of this parser with ESLint, please consider creating a failing integration test which clearly demonstrates the behavior. It's honestly super quick!
You just need to duplicate one of the existing test sub-directories found in tests/integration/
, tweak the dependencies and ESLint config to match what you need, and add a new entry to the docker-compose.yml file which matches the format of the existing ones.
Then run:
npm run integration-tests
If you ever need to change what gets installed when the docker images are built by docker-compose, you will first need to kill the existing containers by running:
npm run kill-integration-test-containers
npm test
- run all linting and testsnpm run lint
- run all lintingnpm run integration-tests
- run only integration testsTypeScript ESLint Parser is licensed under a permissive BSD 2-clause license.
FAQs
An ESLint custom parser which leverages TypeScript ESTree
The npm package @typescript-eslint/parser receives a total of 28,814,490 weekly downloads. As such, @typescript-eslint/parser popularity was classified as popular.
We found that @typescript-eslint/parser demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 2 open source maintainers collaborating on the project.
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