I have migrated my project from v4 to v5, I am only using sx prop. I have not installed @emotion/react and everything is working fine. Is there any reason to install @emotion/react and @emotion/styled? because I havent install it and everything is running good.

"@mui/icons-material": "^5.0.1",
"@mui/lab": "^5.0.0-alpha.48",
"@mui/material": "^5.0.1",

CodePudding user response：

If you install MUI packages without extra configuration, you're using the default style engine powered by emotion, as opposed to the other official style engine that uses styled-component which needs more setup.

To use the default style engine, you need to install the 2 emotion packages as outlined in the installation guide:

npm install @mui/material @emotion/react @emotion/styled

Even when you only use the MUI icons from @mui/icons-material package, you also need the above 2 packages as explained in this answer. The only reason I can think why you don't have any error is because you're not using any MUI components yet, or you're using some unstyled components like the UnstyledButton which is a raw component that doesn't have any styles applied to it.

CodePudding user response：

You need both of them as per the installation guide

// with npm
npm install @mui/material @emotion/react @emotion/styled

// with yarn
yarn add @mui/material @emotion/react @emotion/styled