Allow custom value stringify

[gomain]

I have a case where a backend accepts values say for a key created accepts a date range of the format:

https://domain.com/endpoint?created=2000-01-01T11:22:33Z...2000-01-01T11:22:33Z

For that I have a custom type

type DateRange = {
  from: Date,
  to: Date,
};

And my query type:

type Query = {
  created: DateRange,
  somethingElse: unknown,
};

Now passing this to qs I need to:

  const query: Query = { .. };
  const seflImplementedStringify(rage: DateRange): string = .. ;
  const queryString = qs.stringify({
     ...query,
    // override `created`
    created: selfImplementedStringify(query.created),
  });

Now this gets cumbersome when DateRange is reused across multiple api, multiple keys, ...

I request feature that would allow this:

const queryString = qs.stringify(
    query,
    {
      serializer: (value: unknown) => {
          if (isDateRagne(value)) {
            return selfImplementedStringify(value);
          }
          return SENITAL_TO_INDICATE_LET_QS_DO_ITS_THING;
        },
      },
    },
  );

or perhaps

const queryString = qs.stringify(
    query,
    {
      serializers: [
          [ isDateRange, selfImplementedStringify ],
      ],
    },
  );

This would allow any sort of custom serialization to be handled in user land. On top of the great defaults and options that qs already provides. Not just for Dates.

[gomain]

OK, this feature is actually available through the filter option.

  const queryString = qs.stringify(
    query,
    {
      filter: (prefix: string, value: unknown) => {
          if (isDateRagne(value)) {
            return selfImplementedStringify(value);
          }
          return value;
        },
      },
    },
  );

This would have been more obvious had the option was named filterMap.

[gomain]

created #447 and #448

[ljharb]

Sounds like your issue was resolved.