$in: [] returning unexpected results

[j2L4e]

This happens on the client with feathers-rest and axios:

.find({
  query: {
    foo: {
      $in: foos
    }
  }
});

With foos = [] this produces an HTTP request with an empty query string, i.e. a plain .find() and thus it returns all records.

I'd expect it to actually return an emtpy array.

As a workaround i use which returns the expected result (none) for an empty foos array.

.find({
  query: {
    foo: {
      $in: [...foos, '__dummy']
    }
  }
});

[daffl]

This is a limitation on how query strings work and not really anything we can change. As the qs documentation states:

Key with no values (such as an empty object or array) will return nothing:

assert.equal(qs.stringify({ a: [] }), '');
assert.equal(qs.stringify({ a: {} }), '');
assert.equal(qs.stringify({ a: [{}] }), '');
assert.equal(qs.stringify({ a: { b: []} }), '');
assert.equal(qs.stringify({ a: { b: {}} }), '');

[j2L4e]

I see, thanks for clarifying.