.eslintrc.json

{
  "env": {
    "es6": true,
    "node": true
  },
  "globals": {
    "AbortController": true,
    "fetch": true,
    "FormData": true
  },
  "ignorePatterns": [ "**/*.min.js" ],
  "overrides": [
    {
      "env": {
        "browser": true
      },
      "files": [ "static/js/**/*.js" ]
    }
  ],
  "parser": "@babel/eslint-parser",
  "parserOptions": {
    "babelOptions": {
      "plugins": [
        "@babel/plugin-syntax-import-assertions"
      ]
    },
    "requireConfigFile": false
  },
  "root": true,
  "rules": {
    "eqeqeq": "error"
  }
}

eslint.config.js

import babelESLintParser from "@babel/eslint-parser";
import globals from "globals";

export default [
  {
    ignores: [ "**/*.min.js" ],
    languageOptions: {
      globals: {
        ...globals.node,
        AbortController: true,
        FormData: true,
        fetch: true
      },
      parser: "babel/eslint-parser",
      parserOptions: {
        babelOptions: {
          plugins: [
            "@babel/plugin-syntax-import-assertions"
          ]
        },
        requireConfigFile: false
      }
    },
    plugins: {
      babel: {
        parsers: {
          "eslint-parser": babelESLintParser
        }
      }
    },
    rules: {
      eqeqeq: "error"
    }
  },
  {
    files: [ "static/js/**/*.js" ],
    languageOptions: {
      globals: {
        ...globals.browser
      }
    }
  }
];