fix(Dropdown): do not close on click when search is empty

[rajchourasia]

Fixes #1451 . Mimics the behaviour of SUI core in similar scenario.

[codecov-io]

Codecov Report

Merging #1490 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1490      +/-   ##
==========================================
+ Coverage   99.74%   99.74%   +<.01%     
==========================================
  Files         141      141              
  Lines        2371     2378       +7     
==========================================
+ Hits         2365     2372       +7     
  Misses          6        6

Impacted Files	Coverage Δ
src/modules/Dropdown/Dropdown.js	100% <100%> (ø)	⬆️

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[layershifter]

Can we simplify logic there?

toggle = (e) => {
  if (this.state.open) {
    this.open(e)
    return
  }

  const { search } = this.props
  const options = this.getMenuOptions()

  if (search && _.isEmpty(options)) {
    e.preventDefault()
    return
  }

  this.close(e)
}

It looks more readable to me.

[levithomason]

Thanks for writing a test for this as well. This is a good stop-gap for now, however, the SUI core dropdown still allows toggling an empty search dropdown when the icon is clicked:

We should address that at some point.

[levithomason]

Released in semantic-ui-react@0.67.2.