ANSI Colors for Deno

ColorMee

ANSI styling for Deno

Usage

// TODO: the links may need to be changed.
import {
  BackgroundCode, ForegroundCode, StyleCode, createStyle,
} from 'https://raw.githubusercontent.com/quilicicf/ColorMee/master/createStyle.ts';
import {
  parse, applyStyle, StyleMode,
} from 'https://raw.githubusercontent.com/quilicicf/ColorMee/master/index.ts';

const boldCyanOnRed = createStyle({
  foreground: ForegroundCode.Cyan,
  background: BackgroundCode.Red,
  style: StyleCode.Bold,
});

const parameter = 'this';
console.log(applyStyle(
  parse`I'm styling ${parameter}, but not ${parameter}.`,
  [ boldCyanOnRed, null /* Null style => no style */ ],
));

ℹ️ You can find more examples in 🔗 the tests

Why

I was tired of reading the common pattern that mixes style and content and usually does not support batch (no-color/style) mode:

import { red, bold, blue } from 'anyLib';

console.log(`${red(commit.sha)} ${bold(blue(`<${commit.owner}>`))}`);

Compare to the following:

import { red, boldBlue } from './graphicalChart.ts'; // Codes are computed using createStyle or just strings
import { parse, applyStyle } from 'ColorMee'; // dummy URL, of course

const styleMode = computeStyleModeFromCliArgOrWhatever(); // Allows no-color mode

console.log(
  applyStyle(parse`${commit.sha} ${`<${commit.author}>`}`, [ red, boldBlue ], styleMode)
);

For what usage

I wrote this lib to have a lib that would allow theming for a CLI tool.

The idea is to support theming and batch-mode (understand a --no-color mode).

Modules

• index.ts: apply styles on a template literal
• createStyle.ts: create ANSI code with a user-friendly API. This does not need to be included in your code (it’s the heaviest module, you might want to watch bundle size) but can be used as a tool to create your templates for example
• loadTemplate.ts: load a template and make sure it is consistent with a reference template. This allows you to create a default color scheme for your CLI tool and let anyone theme it by loading another template

The only module that is required is the applyStyle module (in index.ts).

Philosophy

The goal is to follow the philosophy below:

• IDE-integrated: uses real template literals!

• simple: straight-forward API, I don’t handle the parsing!

• maintainable: the whole algorithm is 40 lines long and annotated

• efficient: the algorithm uses the smallest possible amount of ANSI codes

• fail fast and hard: the lib throws ASAP if it finds an error

• small:

  Module	Bundled size	Minified size
  applyStyle (index)	1.6 Kb	772.0 b
  createStyle	5.4 Kb	2.8 Kb
  loadTemplate	784.0 b	466.0 b

My regrets:

• the template string mechanism can’t statically check for errors, but I find that the price to pay is pretty small compared to the gains
• the validation of the template is a bit clumsy at the moment, I’d like to try using runtypes to check that the template conforms to the provided interface but no library of this type has been ported to Deno to my knowledge (although for runtypes it seems to be happening)

Download Details:

Author: quilicicf

Source Code: https://github.com/quilicicf/ColorMee

#deno #node #nodejs #javascript