[INTENT TO DEPRECATE] Remove support for IE8 and remove shimming code in Less

[matthew-dean]

Any comments / opposition to dropping IE8 support?

Also, any reason to keep support for Node 0.12? Seems like Node 4+ is a suitable target now?

[matthew-dean]

Related to: #3121

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[matthew-dean]

Just to be clear, Less is now on 4+ and I'm changing this to something that should happen. Anything IE8-10 specific in the code base or tests should be removed.

[jfitzsimmons]

I was going to give this a go.

From what I can tell their is a Grunt command

`node bin/lessc --ie-compat ${lessFolder}/_main/lazy-eval.less tmp/lazy-eval.css`,

which currently the flag just warns of deprecation and nothing else

case 'ie-compat': console.warn('The --ie-compat option is deprecated, as it has no effect on compilation.'); break;

may be a few other Grunt tweaks.

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the are also 2 tests around multiple Guards for ie8

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and there is a detached ruleset for ie9 that is also used in the docs as an example for detached rulesets:
https://github.com/less/less-docs/blob/master/content/features/detached-rulesets.md

[matthew-dean]

@jfitzsimmons On the test level, yes, but I meant there might be shims for Promises or other browser shims within the codebase itself that are now irrelevant. I can't remember if the browser shim was removed or not.

[jfitzsimmons]

@matthew-dean I'm not seeing anything jump out in the source. Do you have an example area of concern? or a rough idea of features that may have needed shimming?

Was the ie-compat plugin being used for shimming? #3446

[matthew-dean]

@jfitzsimmons To be honest, I opened this in 2017, so I have no idea if I or someone else addressed this by now.

[SarveshChandnani]

is this bug still open to work on?

[iChenLei]

Yes , @SarveshChandnani