Attribution links only identified by colour

[minorOffense]

The maps have 'leaflet' link which is identified only by color.

Criteria 1.4.1
Compliance success level A

• I've looked at the documentation to make sure the behavior is documented and expected
• I'm sure this is a Leaflet code issue, not an issue with my own code nor with the framework I'm using (Cordova, Ionic, Angular, React…)
• I've searched through the issues to make sure it's not yet reported

Steps to reproduce
Steps to reproduce the behavior:

• View a map
• Look at the link text in the bottom right
• No visual indication that text is a link other than the colour difference

Expected behavior
When the link has focus or hover it should show an underline or some other visual indicator to pass WCAG compliance.
See https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-without-color.html

Current behavior
Only identified by a colour.
See https://www.w3.org/TR/2016/NOTE-WCAG20-TECHS-20161007/F73 for an example failure.

Environment

• Leaflet version: all
• Browser (with version): all
• OS/Platform (with version): all

[Malvoz]

See https://www.w3.org/TR/UNDERSTANDING-WCAG20/visual-audio-contrast-without-color.html

The latest recommendation is https://www.w3.org/WAI/WCAG21/Understanding/use-of-color.html.

No visual indication that text is a link other than the colour difference

According to Technique G183 as long as the difference in lightness (contrast) is 3:1 or greater with the surrounding text they still pass SC 1.4.1 Use of Color. That contrast ratio is currently 2.56 (fails SC 1.4.3 Contrast (Minimum) and 1.4.6 Contrast (Enhanced)).

Expected behavior
When the link has focus or hover it should show an underline

Technique F73 states:

If the non-color cue only happens when the mouse hovers over the link or when the link receives focus, it is still a failure.
so that wouldn't be sufficient, it'd need to always have an underline.

It also states: If the link is a different color and bold it would not fail because the boldness is not color dependent.

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In other words, for links not to fail I believe they should meet at least 1 of the following:

• Preserve the default text-decoration underline (in the default state, not only on hover/focus):
  
  
• Use font-weight: bolder:
  
  
• Have a contrast ratio of 3:1 with the surrounding text