The solution below achieves:

1. Does not lint *.js files (important in my use case)
2. Avoids the tseslint.config() wrapper (I will rarely ever edit the configuration file and don't need the IDE help)
3. Keeps it clean and simple

eslint.config.js

import eslint   from '@eslint/js';
import tseslint from 'typescript-eslint';

export default [
   eslint.configs.recommended,
   ...tseslint.configs.strict,
   { ignores: ['**/*.js'] },
   {
      rules: {
         '@typescript-eslint/no-non-null-assertion': 'off',
      },
   },
];

--ext allows using custom javascript extensions, you can't force ESLint to work for languages other than JavaScript by passing a different file extension to it.

You can try using typescript-eslint-parser to enable ESLint for Typescript - it allows building a syntax tree from typescript code that can be passed to ESLint for linting.

But I'd suggest using Typescript linters for inspecting TypeScript code. You can try TSLint, for example.

Update: since 2017.1.3, WebStorm supports ESLint + typescript-eslint-parser; you just need to install both typescript plugin and typescript-eslint-parser and modify your ESLint config accordingly:

"parser": "typescript-eslint-parser",
"plugins": ["typescript"]

But, after removing typescript-eslint, esLint appears to function normally.

When you say it functions normally do you mean functions in your IDE (like vscode) or when you run the eslint command? Because most IDEs come with eslint either built in or available as a package and will lint your code in-editor (using a typescript parser under the hood). Without typescript-eslint eslint can't actually parse your typescript files. Try running eslint without it and see if it lets you.

My understanding is that tsc compiles TypeScript to JavaScript unless --noEmit tag is added. With options like "strict": true, it's possible to configure TypeScript rules to check.

ESLint and tsc do different things.

• Running tsc will inform you of type errors, something eslint does not do.
• Running eslint will inform you of linting errors (violations of defined rules) not type errors, something tsc does not do.

ESLint only reports errors from its own linters, it does not report typescript compilation failures. See: https://stackoverflow.com/a/60758789/14073449

The typescript-eslint page explains why it exists pretty well:https://typescript-eslint.io/

ESLint and TypeScript represent code differently internally. ESLint's default JavaScript parser cannot natively read in TypeScript-specific syntax and its rules don't natively have access to TypeScript's type information.