'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' : ''}. It looks something like this: { "plugins": ${JSON.stringify(plugins)} } Flat config requires "plugins" to be an object, like this: { 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 `; };