did it change because of axios or react-searchkit? (sorry if this was mentioned somewhere before)

@kprzerwa searchkit :)

when does it happen that we have filters with the same name?

Good question, I would re-phrase then given the confusion:

/** react-searchkit allows having the same filter multiple times with different values.
   * For this range dates filters, we want each filter to appear only one time with one value
   * (e.g. loan_start_date = `<date>`)
   *

Good question, I would re-phrase then given the confusion:

/** react-searchkit allows having the same filter multiple times with different values.
   * For this range dates filters, we want each filter to appear only one time with one value
   * (e.g. loan_start_date = `<date>`)
   *

To remove the previously selected filter, shouldn't you pass the already selected value first?
E.g. currently I have loan_start_date:2020-01-01 if I select the date loan_start_date:2019-01-01, shouldn't we pass:
[['loan_start_date', '2020-01-01'], ['loan_start_date', '2019-01-01']]

That was indeed my initial understanding, but in the searchkit the comparison we do not check for the value, we only check if it matches the starting part. So if there is any value we pass ['loan_start_date', ''] to clear it.

Unfortunately this is not the case, see tests that you wrote too. This is related to this bug: it happens that since the string is empty, it clears out all filters selected for this filter. If we fix that bug, we might break this code.
Please change it to something like (pseudo-code):

onDateChange = newSelectedValue => {
    const resetPreviousValue = getFromRSKCurrentQueryState()
    const newFilters = [resetPreviousValue];
    if (!isEmpty(newSelectedValue)) {
        newFilters.push(newSelectedValue);
    }
    return this.props.updateQueryState({ filters: newFilters });
  };

I don't understand this if. If empty, it means that before might had a value, so you should call updateQueryState with the previous value.
If it had no value even before, then just return, nothing to do.
I would simply remove this if. WDYT?

I am not sure I understand all this manipulation of values and different cases.
Here my reasoning:

case 1:

• current: []
• newFilter: ['loan_start_date', '2020-01-01']
• call this.props.updateQueryState({ filters: [ ['loan_start_date', '2020-01-01'] ] });

case 2:

• current: ['loan_start_date', '2020-01-01']
• newFilter: ['loan_start_date', '2021-02-02']
• call this.props.updateQueryState({ filters: [ ['loan_start_date', '2020-01-01'], ['loan_start_date', '2021-02-02'] ] });

In any case, we always pass the previous value to remove it, and eventually if a new one is set, add it.

onDateChange = newFilter => {
      const [name, value] = newFilter;
      const newFilters = this.props.currentQueryState.filters

      // if there is a new date, add it to the current filters so that the previous date is removed and the new one is added.
      // if the date is cleared, then just leave the previous date in the filters so that it will be remove
      const hasSelectedNewDate = !_isEmtpy(value);
      if (hasSelectedNewDate) {
          newFilters.push(newFilter)
      }

      return this.props.updateQueryState({ filters: newFilters });
}

@ntarocco I see what you mean and I am sorry for the confusion it was very messy I cleaned it up according to your suggestions, thanks!