"use strict"; module.exports = function({ plugins }) { const isArrayOfStrings = typeof plugins[0] === "string"; return ` A config object has a "plugins" key defined as an array${isArrayOfStrings ? " of strings" : ""}. Flat config requires "plugins" to be an object in this form: { plugins: { ${isArrayOfStrings && plugins[0] ? plugins[0] : "namespace"}: pluginObject } } Please see the following page for information on how to convert your config object into the correct format: https://eslint.org/docs/latest/use/configure/migration-guide#importing-plugins-and-custom-parsers If you're using a shareable config that you cannot rewrite in flat config format, then use the compatibility utility: https://eslint.org/docs/latest/use/configure/migration-guide#using-eslintrc-configs-in-flat-config `; };