Linting and Code Style
A linter is a tool that analizes source code to flag programming errors, bugs, stylistic errors, and suspicious constructs. In particular, it helps teams to keep the code consistent between their members.
For example, with ESLint, the rule @typescript-eslint/quotes: single
enforces the use of single quotes throughout the code.
// Valid
const foo = 'bar';
// Invalid
const foo = "bar";
ESLint & TypeScript
FoalTS offers a pre-configuration for the linter ESLint. It is the most commonly used in the JavaScript ecosystem and can work with TypeScript through the @typescript-eslint/parser
and @typescript-eslint/eslint-plugin
packages.
You can run the linting with this command:
npm run lint
And if the linting issues can be automatically fixed, you can also fix them with this command:
npm run lint:fix
Adding New Rules
The rules are specified in the .eslintrc
configuration file located at the root of the project.
The list of available JavaScript rules can be found on the ESLint website. Some of them are compatible with TypeScript. Others are not and you will need to find equivalents here.