no id:scoped for repeated w-id

[mlrawlings]

Description

In Marko 3, w-id was used as both a key and set a scoped id. The id was primarily an implementation detail, but it could also be used with w-for to associate DOM elements.

Marko 3:

<label w-for="foo"/>
<input w-id="foo"/>

Marko 4 equivalent:

<label for:scoped="foo"/>
<input key="foo" id:scoped="foo"/>

However Marko 4's :scoped modifier does not support repeated values. This is because it's difficult to reason about association of repeated values (the primary use-case fore :scoped). However, this causes the same ids to appear on the page because :scoped doesn't have special behavior for repeated[] values.

In Marko 3, this association doesn't actually work between repeated w-id and w-for attributes:

Input template:

<label w-for="foo[]">1</label>
<input w-id="foo[]" value="1">
<label w-for="foo[]">2</label>
<input w-id="foo[]" value="2">

Output HTML:

<label for="foo[0]">1</label>
<input id="foo[1]" value="1">
<label for="foo[2]">2</label>
<input id="foo[3]" value="2">

Because of this, it should be safe to assume that a repeated w-id is only being used to reference the elements, not associate them with other elements. This PR modifies the migration of w-id so that repeated ids do not add an id:scoped attribute.

Checklist:

• I have read the CONTRIBUTING document and have signed (or will sign) the CLA.
• I have updated/added documentation affected by my changes.
• I have added tests to cover my changes.

[codecov]

Codecov Report

Merging #1377 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #1377      +/-   ##
==========================================
+ Coverage   90.59%   90.59%   +<.01%     
==========================================
  Files         341      341              
  Lines       12467    12468       +1     
==========================================
+ Hits        11294    11295       +1     
  Misses       1173     1173

Impacted Files	Coverage Δ
src/core-tags/migrate/all-tags/w-id.js	100% <100%> (ø)	⬆️

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[coveralls]

Coverage increased (+0.0008%) to 90.592% when pulling a80ad07 on w-id-repeated into 535daf9 on master.

[coveralls]

Coverage increased (+0.0008%) to 90.592% when pulling a80ad07 on w-id-repeated into 535daf9 on master.