[core] Components crash when required prop is missing

[fredprodibi]

• [x ] The issue is present in the latest release.
• [ x] I have searched the issues of this repository and believe that this is not a duplicate.

Current Behavior 😯

if ariaLabel is missing the component crashes

Expected Behavior 🤔

Steps to Reproduce 🕹

take the demo and remove ariaLabel

Steps:

Context 🔦

Your Environment 🌎

Tech	Version
Material-UI	v4.?.?
React
Browser
TypeScript
etc.

[oliviertassinari]

This prop is required. We have other components that crash when a required prop is missing or wrong, this problem is not specific to the Speed Dial. Could you expand on the concern? Thanks.

The list of components that crash on missing required props (as far as I'm aware of):

• SpeedDial
• ExpansionPanel
• Tooltip
• FormControlLabel
• Modal
• TrapFocus

Note that you won't see the prop-type warning when rendering on the server.

[fredprodibi]

Hello, when you know it it's fine.

It's my first project with meterial UI and it wasn't simple to figure out what was wrong as the error wasn't "requiered prop ariaLabel is missing", but something like "replace is not a method of undefined"

[oliviertassinari]

It's my first project with meterial UI and it wasn't simple to figure out what was wrong as the error wasn't "requiered prop ariaLabel is missing", but something like "replace is not a method of undefined"

@fredprodibi Thanks! It seems that the warning message gets buried down by the exception and its stack trace.

I'm in favor of adding defensive checks in the codebase to avoid these crashes and have the prop types warning messages easier to follow. What do you think @eps1lon?

[eps1lon]

It's my first project with meterial UI and it wasn't simple to figure out what was wrong as the error wasn't "requiered prop ariaLabel is missing", but something like "replace is not a method of undefined"

I understand your confusion. This caused by the error screen of create react app only having a tiny hint to check your console. This also might happen when you stop reading the log when the last error occured. I would recommend to either start at the top of your error log or don't stop reading when you see the first error log.

In this specific example above the "replace is not a method of undefined" an additional error should be logged telling you that Warning: Failed prop type: The prop ariaLabel is marked as required in ForwardRef(SpeedDial), but its value is undefined.

[oliviertassinari]

I think that we can keep the components crash when they miss important props.