Theming

[phated]

@sttk @erikkemperman @tdeschryver I've begun experimenting with a solution to chalk replacement that utilizes yargs to parse --color/--no-color and replaces direct color names to work towards #63

There's still some problems with this approach so I may use @tdeschryver's solution of checking the process.argv directly for --no-colors

I just wanted to open this to get some more eyes on it.

[erikkemperman]

@phated Sorry, I don't really have an opinion on this... Well, not an opinion that you don't already know, anyway :-) Having said that, it's probably just a typo above but is it --no-color or --no-colors?

[sttk]

This pr makes clear coloring and easy to add a function of configuring colors.

However some names are ambiguous, e.g. flag and desc. I think it's better to use property tree or consistent prefix for categorizing.

About --no-color(s), chalk supports flags: --no-color, --color=false, --no-colors for color-off, and flags: --color, --colors, --color=true, --color=always, and more flags for 256 or 16m colors for color-on. But I think it's OK to support only the flags: --color and --no-color which are announced in CLI document.

[phated]

@sttk good points.

I was actually trying to add some more work onto this but ran into a problem because we register the logger more than once and need to clean it up. I'm starting to think the config-file stuff shouldn't be within liftoff but instead should be within the argv parser. Thoughts?

[sttk]

I've created a package: ansi-colors-nestable and ansi-colors-prioritized to extend ansi-colors. Are these usable?

To this pr, I tried to suggest about help message, such as:

var usage = `\n' +
  color.helpUsage('Usage:') + ' '
  color.helpSyntax('gulp ' + color.helpOptions('[options]') + ' tasks');

but ansi-color doesn't support nesting, and ' tasks' above is no color.

ansi-colors-nestable enables this as follows:

var nestableColor = require('ansi-colors-nestable');

color.helpSyntax = nestableColor('(color-name)');

var usage = `\n' +
  color.helpUsage('Usage:') + ' '
  color.helpSyntax('gulp ', color.helpOptions('[options]'), ' tasks');

Another one, ansi-colors-prioritized enables to set multiple colors with priority.
This would be useful for users who want to customize colors both in details and roughly.
For example:

var prioritizedColors = require('ansi-colors-prioritized');

var colorCfg = {
  ...
  require: {
    fail: '',
    moduleName: 'magenta',
  },
  system: {
    error: 'bgred',
  },
  ...
  moduleName: 'bold',
  error: 'red',
  ...
}

// ansiColors.bgred is used in this case.
color.requireFail = prioritizedColors(colorCfg.require.fail, colorCfg.system.error, colorCfg.error);

// ansiColors.bold is used in this case.
color.requiredModule = prioritizedColors(colorCfg.require.moduleName, colorCfg.moduleName);

log.error(
  color.requireFail('Failed to load external module ', color.requiredModule(name))
);

[phated]

@sttk those are some interesting modules, but my thoughts are converging on using template strings

Something like:

var usage = '\n{helpUsage}Usage:{/helpUsage} {helpSyntax}gulp {helpOptions}[options]{/helpOptions} tasks{/helpSyntax}'

But I'm not happy with that verbosity and I'd like to solve argument replacement as well so we don't have to use string concatenation (probably using printf-style variables like %s)