[Snackbar] Improve accessibility

[oliviertassinari]

A continuation of #19016 in a standalone pull request. As requested by @eps1lon.

[mui-pr-bot]

Details of bundle changes.

Comparing: ee46512...d59bca9

bundle	Size Change	Size	Gzip Change	Gzip
@material-ui/core[umd]	▲ +20 B (+0.01% )	314 kB	▲ +21 B (+0.02% )	90.6 kB
@material-ui/core	▲ +20 B (+0.01% )	358 kB	▼ -9 B (-0.01% )	98.2 kB
docs.main	▲ +20 B (0.00% )	614 kB	▲ +7 B (0.00% )	196 kB
Snackbar	▲ +20 B (+0.03% )	74.9 kB	▲ +5 B (+0.02% )	23.5 kB
@material-ui/lab	--	182 kB	--	54.6 kB
@material-ui/styles	--	50.8 kB	--	15.3 kB
@material-ui/system	--	14.5 kB	--	4.04 kB
Alert	--	83.5 kB	--	26.2 kB
AlertTitle	--	63.9 kB	--	20.2 kB
AppBar	--	63.7 kB	--	20 kB
Autocomplete	--	129 kB	--	40.6 kB
Avatar	--	65 kB	--	20.6 kB
AvatarGroup	--	62 kB	--	19.5 kB
Backdrop	--	67.5 kB	--	20.9 kB
Badge	--	65.1 kB	--	20.3 kB
BottomNavigation	--	62.2 kB	--	19.5 kB
BottomNavigationAction	--	75.2 kB	--	23.8 kB
Box	--	70.5 kB	--	21.5 kB
Breadcrumbs	--	67.7 kB	--	21.3 kB
Button	--	79.4 kB	--	24.4 kB
ButtonBase	--	73.7 kB	--	23.2 kB
ButtonGroup	--	82.9 kB	--	25.5 kB
Card	--	62.6 kB	--	19.6 kB
CardActionArea	--	74.8 kB	--	23.6 kB
CardActions	--	61.8 kB	--	19.4 kB
CardContent	--	61.7 kB	--	19.4 kB
CardHeader	--	64.8 kB	--	20.4 kB
CardMedia	--	62.1 kB	--	19.6 kB
Checkbox	--	81.7 kB	--	25.9 kB
Chip	--	82.3 kB	--	25.3 kB
CircularProgress	--	63.9 kB	--	20.2 kB
ClickAwayListener	--	3.85 kB	--	1.54 kB
Collapse	--	67.6 kB	--	21 kB
colorManipulator	--	3.85 kB	--	1.52 kB
Container	--	63 kB	--	19.8 kB
CssBaseline	--	57.3 kB	--	18 kB
Dialog	--	82.5 kB	--	25.9 kB
DialogActions	--	61.9 kB	--	19.5 kB
DialogContent	--	62 kB	--	19.5 kB
DialogContentText	--	63.8 kB	--	20.1 kB
DialogTitle	--	64 kB	--	20.1 kB
Divider	--	62.3 kB	--	19.7 kB
docs.landing	--	50.7 kB	--	13.4 kB
Drawer	--	84.2 kB	--	25.7 kB
ExpansionPanel	--	71.1 kB	--	22.3 kB
ExpansionPanelActions	--	61.8 kB	--	19.4 kB
ExpansionPanelDetails	--	61.7 kB	--	19.4 kB
ExpansionPanelSummary	--	77.8 kB	--	24.6 kB
Fab	--	76.5 kB	--	23.9 kB
Fade	--	23.3 kB	--	8 kB
FilledInput	--	73.3 kB	--	22.8 kB
FormControl	--	64.1 kB	--	20 kB
FormControlLabel	--	65.3 kB	--	20.5 kB
FormGroup	--	61.8 kB	--	19.4 kB
FormHelperText	--	63 kB	--	19.8 kB
FormLabel	--	63.2 kB	--	19.7 kB
Grid	--	64.9 kB	--	20.4 kB
GridList	--	62.2 kB	--	19.6 kB
GridListTile	--	63.5 kB	--	20 kB
GridListTileBar	--	63 kB	--	19.8 kB
Grow	--	23.9 kB	--	8.21 kB
Hidden	--	65.7 kB	--	20.7 kB
Icon	--	62.5 kB	--	19.7 kB
IconButton	--	75.9 kB	--	23.7 kB
Input	--	72.2 kB	--	22.6 kB
InputAdornment	--	64.8 kB	--	20.5 kB
InputBase	--	70.3 kB	--	22.1 kB
InputLabel	--	65.1 kB	--	20.1 kB
LinearProgress	--	65.1 kB	--	20.4 kB
Link	--	66.4 kB	--	21 kB
List	--	62.1 kB	--	19.4 kB
ListItem	--	76.9 kB	--	24.1 kB
ListItemAvatar	--	61.9 kB	--	19.4 kB
ListItemIcon	--	61.9 kB	--	19.4 kB
ListItemSecondaryAction	--	61.8 kB	--	19.4 kB
ListItemText	--	64.7 kB	--	20.4 kB
ListSubheader	--	62.5 kB	--	19.7 kB
Menu	--	88.2 kB	--	27.3 kB
MenuItem	--	77.9 kB	--	24.4 kB
MenuList	--	65.7 kB	--	20.6 kB
MobileStepper	--	67.6 kB	--	21.3 kB
Modal	--	14.3 kB	--	5.01 kB
NativeSelect	--	76.6 kB	--	24.2 kB
NoSsr	--	2.19 kB	--	1.03 kB
OutlinedInput	--	73.7 kB	--	23 kB
Paper	--	62.1 kB	--	19.4 kB
Popover	--	82.5 kB	--	25.7 kB
Popper	--	28.7 kB	--	10.3 kB
Portal	--	2.9 kB	--	1.3 kB
Radio	--	82.7 kB	--	26.2 kB
RadioGroup	--	63.2 kB	--	19.9 kB
Rating	--	70 kB	--	22.5 kB
RootRef	--	4.21 kB	--	1.64 kB
Select	--	114 kB	--	34 kB
Skeleton	--	62.7 kB	--	19.9 kB
Slide	--	25.3 kB	--	8.72 kB
Slider	--	75.3 kB	--	23.9 kB
SnackbarContent	--	63.3 kB	--	20 kB
SpeedDial	--	85.8 kB	--	27.1 kB
SpeedDialAction	--	117 kB	--	37.1 kB
SpeedDialIcon	--	64.3 kB	--	20.2 kB
Step	--	62.4 kB	--	19.6 kB
StepButton	--	82 kB	--	26 kB
StepConnector	--	62.5 kB	--	19.7 kB
StepContent	--	68.8 kB	--	21.6 kB
StepIcon	--	64.4 kB	--	20.1 kB
StepLabel	--	68.3 kB	--	21.6 kB
Stepper	--	64.6 kB	--	20.4 kB
styles/createMuiTheme	--	16.5 kB	--	5.85 kB
SvgIcon	--	62.8 kB	--	19.7 kB
SwipeableDrawer	--	91.6 kB	--	28.7 kB
Switch	--	80.9 kB	--	25.5 kB
Tab	--	76.1 kB	--	24.1 kB
Table	--	62.3 kB	--	19.6 kB
TableBody	--	61.9 kB	--	19.4 kB
TableCell	--	63.8 kB	--	20.2 kB
TableContainer	--	61.7 kB	--	19.4 kB
TableFooter	--	61.9 kB	--	19.4 kB
TableHead	--	61.9 kB	--	19.4 kB
TablePagination	--	141 kB	--	41.3 kB
TableRow	--	62.3 kB	--	19.6 kB
TableSortLabel	--	77.1 kB	--	24.3 kB
Tabs	--	85.2 kB	--	27.1 kB
TextareaAutosize	--	5.09 kB	--	2.14 kB
TextField	--	123 kB	--	36.1 kB
ToggleButton	--	75.9 kB	--	24.1 kB
ToggleButtonGroup	--	63 kB	--	19.9 kB
Toolbar	--	62.1 kB	--	19.6 kB
Tooltip	--	101 kB	--	31.9 kB
TreeItem	--	73.5 kB	--	23.3 kB
TreeView	--	66.1 kB	--	20.8 kB
Typography	--	63.4 kB	--	19.9 kB
useAutocomplete	--	12.7 kB	--	4.71 kB
useMediaQuery	--	2.5 kB	--	1.06 kB
Zoom	--	23.4 kB	--	8.11 kB

Generated by 🚫 dangerJS against d59bca9

Updated

[eps1lon]

I'm a bit lost how the autoHide duration relates to the aria-describedby change. Could you elaborate a bit what you're trying to do in this PR?

[oliviertassinari]

@eps1lon I have tried to clean up the overall handling of accessibility for the component. MDN says that the aria-describedby is required when using the role alertdialog. Since we have stopped using this role, to use alert instead, and that all the implementations I could benchmark announce everything in the alert, I have concluded that we could remove code from the demos (the ids were added in the initial pull request to follow MDN in 2017: #7059).

Then, Matt made me have a deeper dive at the alertdialog role, given that the snackbar doesn't have the capability to make an interaction with the snackbar "required" like the modal can, I believe we shouldn't even mention the role.

[oliviertassinari]

@eps1lon What do you think?