add a plugin option to support passing options cssnano v4

[tommytroylin]

for issue #69 #71

add a cssProcessorPluginOptions as a third arg passed to cssProcessor

[kidBrazil]

Is this still being used?

[tommytroylin]

yes， postcss needs the same options in old versions
{ from, to }

As a convenience, plugins also expose a process method so that you can use them as standalone tools.

cleaner.process(css, processOpts, pluginOpts)
// This is equivalent to:
postcss([ cleaner(pluginOpts) ]).process(css, processOpts)

from postcss api

[mirucon]

Been having the issue with the option, and this PR completely solved it! +1 for merging this.

[NMFR]

Was thinking if this should be implemented with a cssProcessorOptionsArgs option.

If cssProcessorOptionsArgs was not passed use:
cssProcessor.process(css, cssProcessorOptions)

If cssProcessorOptionsArgs was passed, ignore the value of cssProcessorOptions and use cssProcessorOptionsArgs for the rest of the arguments after the css:
cssProcessor.process(css, ...cssProcessorOptionsArgs)

But the ignoring cssProcessorOptions part fells bad.

What do you think?

[tommytroylin]

@NMFR
I also fell bad when ignoring it.
I'm thinking if we can make sure that cssProcessorOptions should be an object. maybe we can reuse this arg name;

There are 3 solutions now:

1. Keep old cssProcessorOptions. Add cssProcessorPluginOptions for pluginsOptions
2. Keep old cssProcessorOptions. Add cssProcessorOptionsArgs Array, when it was passed, ignore cssProcessorOptions and spread cssProcessorOptionsArgs to that plugin call
3. if cssProcessorOptions is object, it should work as same as now. But if it is an array, spread it to plugin call

Idk which one would you guys prefer.

[NMFR]

I don't think solution 3 is a good ideia, it would make it weird if the first parameter was an array.

Going with solution 1 since its more retro compatible.

[NMFR]

Many thx for the help