There is component named Text in my project. ESLint doesn't tell me that Text is undefined because it's existing class in the DOM API.
I suggest add rule which deny use components defined globally:

{ "rules": { "react/jsx-no-undef": ["error", { "onlyImported": true }] } }

import Text from './Text'; <Text /> // ok

<Text /> // react/jsx-no-undef: 'Text' component not found in current scope.