Cleanup injected attribution <style> and <script> tags

[jfolds]

<style> and <script> tags are injected into the page for attribution reasons when adding basemap layers. There should probably be a way to either: a) prevent injecting <script> or <style> tags into the page or b) remove the injected tags when a map is destroyed

[jfolds]

Would adding a map "unload" event listener here: https://github.com/Esri/esri-leaflet/blob/master/src/Util.js#L199 be a valid option? something like:

    map.on('unload', function() {
      hoverAttributionStyle.remove();
      attributionStyle.remove();
    });

The above not accounting for <script> tags inserted. Would adding classes to the scripts be reasonable?

    map.on('unload', function() {
      hoverAttributionStyle.remove();
      attributionStyle.remove();
      // remove scripts with custom class name
      var nodeList = document.getElementsByClassName('esri-leaflet-jsonp-script');
      for (var i = 0; i < nodeList.length; i++) {
        nodeList.item(i).remove();
      }
    });

Anyway, just some suggestions to get the conversation started.

Thanks!

[jgravois]

all that seems reasonable enough to me. thanks for chewing on it!

[jfolds]

So, this works for removing scripts/styles on unload:
dtsagile@2bd4f65

However, tests now fail...having a hard time deciphering the issue. Even adding an empty "unload" event in Util.js causes test failures for me. (Map container instance is being reused?)

Any advice welcome, thanks!

OS: Windows 10
Node version: 6.10.1
NPM version: 3.10.10

[jgravois]

its possible that my changes to the test suite in #1025 will help.