[material-ui][InputBase] onBlur called with undefined event contrary to type definition

Hello 👋

Search keywords

undefined event onBlur

Latest version

• I have tested the latest version

Steps to reproduce

Steps:

1. Open this link to live example: https://stackblitz.com/edit/react-zufzmfhc?file=Demo.tsx
2. Type something in the input
3. See in the console that the event passed to onBlur is undefined if the InputBase is disabled

Current behavior

InputBase is calling onBlur with an undefined event in certain cases, but the type definition for onBlur does not have a nullable event:

/**
* Callback fired when the `input` is blurred.
*
* Notice that the first argument (event) might be undefined.
*/
onBlur?: React.FocusEventHandler<HTMLInputElement | HTMLTextAreaElement>;

Even though there is a comment, undefined is not an option for the events.

Expected behavior

I would have expected the behavior of the onBlur to match the type definition and no undefined event to be passed in. Would it be possible to either update the type definition to include undefined or update the onBlur call to pass in an event for InputBase?

Context

We are running with strict null safety and this is causing an issue.

Your environment

See sandbox: https://stackblitz.com/edit/react-zufzmfhc?file=Demo.tsx

Thank you!

Start with packages/mui-material/src/InputBase/InputBase.js at the linked onBlur call and compare it with the onBlur declaration in packages/mui-material/src/InputBase/InputBase.d.ts. Reproduce the disabled-input case using the linked StackBlitz example, then verify that the runtime behavior and type definition agree.