Adds support for nested chalk expressions.

green(a + blue(b) + c) will now look the same as green(a) +
blue(b) + green(c), as expected. In the previous implementation the
output would have been green(a) + blue(b) + c, because the reset code of
the second expression would close all expressions around it as well.

Now this reset code is replaced by a start code of the outer lying
expression, both stopping the inner and re-starting the outer.

index.js

@@ -22,6 +22,19 @@ var styles = (function () {
 	return ret;
 })();
 
+// enrich each ansiStyle object with regular expression matching
+// all instances of the corresponding code.close
+(function () {
+	var _matchUnescapedCharacters = /[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g;
+	function escapeStr(str) {
+		return str.replace(_matchUnescapedCharacters, '\\$&');
+	}
+
+	Object.keys(ansiStyles).forEach(function (key) {
+		ansiStyles[key].closeRe = new RegExp(escapeStr(ansiStyles[key].close), 'g');
+	});
+})();
+
 function init() {
 	var ret = {};
 
@@ -37,7 +50,12 @@ function init() {
 
 					return self._styles.reduce(function (str, name) {
 						var code = ansiStyles[name];
-						return str ? code.open + str + code.close : '';
+						return str ?
+							// Replace any instances already present with a re-opening code
+							// otherwise only the part of the string until said closing code will be coloured, and the rest will be
+							// simply 'plain'.
+							code.open + str.replace(code.closeRe, code.open) + code.close :
+							'';
 					}, str);
 				}, styles);
 

readme.md

@@ -47,6 +47,9 @@ console.log(  chalk.blue.bgRed.bold('Hello world!')  );
 // nest styles
 console.log(  chalk.red('Hello', chalk.underline.bgBlue('world') + '!')  );
 
+// nest styles of the same type even (colour, underline, background)
+console.log( chalk.green('Hello, I'm a green line ' + chalk.blue('with a blue substring') + ' that becomes green again!') );
+
 // pass in multiple arguments
 console.log(  chalk.blue('Hello', 'World!', 'Foo', 'bar', 'biz', 'baz')  );
 ```

test.js

@@ -21,6 +21,13 @@ describe('chalk', function () {
 		);
 	});
 
+	it('should support nesting styles of the same type (color, underline, bg)', function () {
+		assert.equal(
+			chalk.red('a' + chalk.blue('b' + chalk.green('c') + 'b') + 'c'),
+			'\u001b[31ma\u001b[34mb\u001b[32mc\u001b[34mb\u001b[31mc\u001b[39m'
+		);
+	});
+
 	it('should reset all styles with `.reset()`', function () {
 		assert.equal(chalk.reset(chalk.red.bgGreen.underline('foo') + 'foo'), '\u001b[0m\u001b[4m\u001b[42m\u001b[31mfoo\u001b[39m\u001b[49m\u001b[24mfoo\u001b[0m');
 	});