Fix constructor

[jshjohnson]

Description

As highlighted by @tinovyatkin here, the ability to pass multiple elements to the Choices constructor and get multiple instances back was buggy at best. This PR removes that functionality so the Choices constructor will only ever return one instance and that instance will only be associated with one element. To achieve the same behaviour, you would need to do the following:

const elements = Array.from(document.querySelectorAll('.your-class'));

const instances = elements.map((element) => {
  return new Choices(element);
});

or even simpler:

const elements = Array.from(
  document.querySelectorAll(".your-class"),
  element => new Choices(element)
);

I've also updated the constructor to throw an error if no valid element is passed or no valid element is found in the DOM. Previously this would have failed silently.

How Has This Been Tested?

Constructor tests have been added with this change.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[codecov]

Codecov Report

Merging #693 into master will increase coverage by 0.35%.
The diff coverage is 57.14%.

@@            Coverage Diff             @@
##           master     #693      +/-   ##
==========================================
+ Coverage   66.03%   66.38%   +0.35%     
==========================================
  Files          23       23              
  Lines        1316     1306      -10     
==========================================
- Hits          869      867       -2     
+ Misses        447      439       -8

Impacted Files	Coverage Δ
src/scripts/lib/utils.js	79.16% <100%> (+1.08%)	⬆️
src/scripts/components/wrapped-element.js	93.54% <100%> (ø)	⬆️
src/scripts/components/list.js	24.32% <11.11%> (ø)	⬆️
src/scripts/choices.js	53.98% <62.96%> (+0.35%)	⬆️

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[tinovyatkin]

@jshjohnson Array.from accepts second parameter, so, code may be easier:

const elements = Array.from(
  document.querySelectorAll(".your-class"),
  element => new Choices(element)
);

[jshjohnson]

@jshjohnson Array.from accepts second parameter, so, code may be easier:

Nice - have updated

[tinovyatkin]

Also need to update typings by removing brackets hack.
And probably document behaviour if Choices is constructed with selector that may return several elements (we use document.querySelector to pick the first one)

[tinovyatkin]

@jshjohnson consider also #691 for 8.x 🙏

[jshjohnson]

Also need to update typings by removing brackets hack.
And probably document behaviour if Choices is constructed with selector that may return several elements (we use document.querySelector to pick the first one)

See here: 4435efc - let me know if this is wrong