npm output / logging follow up tasks

[wraithgar]

Epic

This is a follow up to #810

Tasks

Beta Give feedback

1. push out user input (proc-log.read) to dependencies
2. spike on what an "npm is doing something" output should look like
3. rethink how the logger displays content to the end user (i.e. when to show the label)
4. exit-handler (log.error(...errline)) gets logged without log prefixes
5. Color templating by internal names and not color names
6. Consider no logging headers if log level is default (part of logger display rethink)
7. Remove the rest of tabular output? Internal "column output" library?

[wraithgar]

From #810 (comment)

Customizable colors

npmlog used to be in charge of colors which we set once at runtime. The Display class now generate a color palette on load which takes configured options.

Our goal is to have one (1) good and accessible color palette for all output shown to the terminal. BUT if we find cases where that is impossible (eg dark vs light terminal backgrounds) it is now at least possible to have a config option to change colors.

[wraithgar]

From #810 (comment)

Command templates

What if a command could do this?

// producer
const data = { name, version }
output.standard(data, {
  templates: {
    // pick any templating DSL
    human: `{{ name }}@{{ version }}`,
    parseable: `{{ name }}\t{{ version }}`
  }
})

// consumer
process.on('output', (level, data, { templates }) => {
  if (level === 'standard') {
    const templateName = templates[this.human ? 'human' : this.parseable : 'parseable' : '']
    process.stdout.write(template(data, templateName || JSON.stringify))
  }
})