The Chalk Module Can Be Used With The Console's String Interpolation In Node.js

test.js

// Require the core node modules.
var chalk = require( "chalk" );

// ----------------------------------------------------------------------------------- //
// ----------------------------------------------------------------------------------- //

// The approach that I normally use when nesting styles is to include a variable
// number of arguments in the root chalk() call. This allows the styles to build upon
// each other.
// --
// NOTE: Using the "+" in order to prevent a space before the ",".
process.stdout.write( "1: " );
console.log( chalk.red( "Hello", chalk.bold( "Kim" ) + ", I hope you are well." ) );

// The above works perfectly; but, it leaves the code with some readability problems.
// We can try to make the logic and formatting easier to read by using the "formatting"
// functionality of the Console (supplied under the hood by util.format()). Notice that
// in this version, we're using "%s" to interpolate original log message AND that we're
// using chalk in the interpolation value.
process.stdout.write( "2: " );
console.log( chalk.red( "Hello %s, I hope you are well." ), chalk.bold( "Kim" ) );

// Using the Console interpolation, however, doesn't work in all cases. It works for
// any case in which we are NOT OVERRIDING COLORS (foreground or background). Colors
// get some special treatment. But, any non-color modifiers can be used safely in the
// interpolation value.
process.stdout.write( "3: " );
console.log(
	chalk.red( "Hello %s, I %s you are %s." ),

	// Here, are keeping the same COLOR (background / foreground), but we're adding
	// style modifiers. This works! This is cool beans!
	chalk.bold( "Kim" ),
	chalk.underline( "rather hope" ),
	chalk.italic( "happy" )
);

// If we NEST THE STYLES directly, however, we can definitely override colors. This is
// because chalk is smart enough to know styles are being nested and will RE-OPEN the
// previous style when the nested style is closed.
process.stdout.write( "4: " );
console.log( chalk.red( "Hello", chalk.black( "Kim" ) + ", I think you are great!" ) );

// ... however, chalk can only be smart if it is doing the nesting directly. If we rely
// on the console interpolation to do the nesting, chalk doesn't see it, so IT CANNOT
// RE-OPEN THE STYLE. This leaves the remainder of the text with the DEFAULT colors.
// --
// CAUTION: THIS APPROACH DOES NOT WORK (for foreground or background conflicts).
process.stdout.write( "5: " );
console.log( chalk.red( "Hello %s, I think you are great!" ), chalk.black( "Kim" ) );

// Of course, if the outer console item has the DEFAULT background and foreground colors,
// then we can totally use color styles in the interpolation - since the reset just puts
// the style back into the default state.
process.stdout.write( "6: " );
console.log( "Hello %s, so great running into you!", chalk.red.bold( "Kim" ) );

// NOTE: We don't need to use variable arguments in order to get the nested styles to
// work properly. We can use string templates to get the same thing to work. This is
// because chalk is actually using PATTERN MATCHING to find the CLOSE pattern of any
// nested styles in order to replace them with an OPEN pattern of the parent style.
process.stdout.write( "7: " );
var value = chalk.black.bold.underline( "Kim" );
console.log( chalk.red( `Hello ${ value }, rock on with your bad self.` ) );