[DateRangePicker] Allow same date selection

[cloudshadow]

               <DateRangePicker
                  startText="Created From"
                  endText="Created To"
                  allowSameDateSelection={true}
                  value={[
                    searchCriteria.beginDate,
                    searchCriteria.endDate,
                  ]}
                  onChange={}
                  renderInput={(startProps, endProps) => (
                    <React.Fragment>
                      <TextField
                        {...produce(startProps, (draft) => {
                          draft.helperText = '';
                        })}
                      />
                      <DateRangeDelimiter> to </DateRangeDelimiter>
                      <TextField
                        {...produce(endProps, (draft) => {
                          draft.helperText = '';
                        })}
                      />
                    </React.Fragment>
                  )}
                />

i think the issue is in the validateDateRange function. This function not use the allowSameDateSelection to pass the validate of utils.isBefore(range[0], range[1])

[bennoparikh]

I have this problem also. I would appreciate if it could be fixed as fast as possible. Thanks!

[loewe]

Please fix this. We need it!

[oliviertassinari]

It looks like we should remove the allowSameDateSelection prop. The prop is described as:

https://github.com/mui-org/material-ui/blob/35e674311a97a72da806c04ba61e44fae79fdfee/packages/material-ui-lab/src/DesktopDateRangePicker/DesktopDateRangePicker.tsx#L29-L33

As far as I know, there are no valid use cases for it, no matter a date picker, time picker, date range picker, etc. One thing that we have seen in the past is the capability to control the range that can be selected, this is a different problem and require a broader solution.

[havgry]

@oliviertassinari Is this a matter of applying the old PR to this repository or is there more to it?

[oliviertassinari]

@havgry I can't say. I didn't look at the pull request in detail.

[hmaddisb]

@oliviertassinari Maybe you can introduce an or clause like below?

diff --git a/packages/material-ui-lab/src/internal/pickers/date-utils.ts b/packages/material-ui-lab/src/internal/pickers/date-utils.ts
index c3d17b5703..4c1c7a7aa0 100644
--- a/packages/material-ui-lab/src/internal/pickers/date-utils.ts
+++ b/packages/material-ui-lab/src/internal/pickers/date-utils.ts
@@ -128,7 +128,7 @@ export const isRangeValid = <TDate>(
   utils: MuiPickersAdapter<TDate>,
   range: DateRange<TDate> | null,
 ): range is NonEmptyDateRange<TDate> => {
-  return Boolean(range && range[0] && range[1] && utils.isBefore(range[0], range[1]));
+  return Boolean(range && range[0] && range[1] && (utils.isBefore(range[0], range[1]) || utils.isEqual(range[0], range[1])));
 };
 
 export const isWithinRange = <TDate>(

[oliviertassinari]

@hmaddisb I think that we can be more efficient:

diff --git a/packages/material-ui-lab/src/internal/pickers/date-utils.ts b/packages/material-ui-lab/src/internal/pickers/date-utils.ts
index c3d17b5703..63fb4aef06 100644
--- a/packages/material-ui-lab/src/internal/pickers/date-utils.ts
+++ b/packages/material-ui-lab/src/internal/pickers/date-utils.ts
@@ -128,7 +128,8 @@ export const isRangeValid = <TDate>(
   utils: MuiPickersAdapter<TDate>,
   range: DateRange<TDate> | null,
 ): range is NonEmptyDateRange<TDate> => {
-  return Boolean(range && range[0] && range[1] && utils.isBefore(range[0], range[1]));
+  // isBefore is exclusive, if two dates are equal, it returns false.
+  return Boolean(range && range[0] && range[1] && !utils.isBefore(range[1], range[0]));
 };

 export const isWithinRange = <TDate>(

[hmaddisb]

@oliviertassinari that's fair! Should I make a PR for that? Or do you want to introduce more changes for this issue?

[oliviertassinari]

@hmaddisb I think that we can try a pull request :), we would need to add a test.