Add whitespace option (#21)

Author: yaodingyd

bench.js

@@ -12,3 +12,7 @@ bench('strip CSS comments', () => {
 bench('preserve option', () => {
 	stripCssComments(fixture, {preserve: /^!/});
 });
+
+bench('whitespace option', () => {
+	stripCssComments(fixture, {whitespace: false});
+});

index.d.ts

@@ -9,6 +9,13 @@ declare namespace stripCssComments {
 		@default true
 		*/
 		readonly preserve?: boolean | RegExp | ((comment: string) => boolean);
+
+		/**
+		Replace comments with whitespace instead of stripping them entirely.
+
+		@default true
+		*/
+		readonly whitespace?: boolean;
 	}
 }
 

index.js

@@ -3,6 +3,7 @@ const isRegExp = require('is-regexp');
 
 module.exports = (cssString, options = {}) => {
 	let preserveImportant = !(options.preserve === false || options.all === true);
+	const stripWhitespace = options.whitespace === false;
 
 	let preserveFilter;
 	if (typeof options.preserve === 'function') {
@@ -41,11 +42,14 @@ module.exports = (cssString, options = {}) => {
 			for (; j < cssString.length; j++) {
 				// Find end of comment
 				if (cssString[j] === '*' && cssString[j + 1] === '/') {
-					if (preserveImportant && isImportantComment) {
+					if ((preserveImportant && isImportantComment) || (preserveFilter && preserveFilter(comment))) {
 						returnValue += `/*${comment}*/`;
-					} else if (preserveFilter) {
-						// Evaluate comment text
-						returnValue = preserveFilter(comment) ? returnValue + `/*${comment}*/` : returnValue;
+					} else if (stripWhitespace) {
+						if (cssString[j + 2] === '\n') {
+							j++;
+						} else if (cssString[j + 2] + cssString[j + 3] === '\r\n') {
+							j += 2;
+						}
 					}
 
 					comment = '';

index.test-d.ts

@@ -20,3 +20,8 @@ expectType<string>(
 		preserve: comment => comment.charAt(0) === '#'
 	})
 );
+expectType<string>(
+	stripCssComments('/*# preserved */ body { /* unicorns */color: hotpink; }', {
+		whitespace: false
+	})
+);

readme.md

@@ -70,6 +70,12 @@ Default: `true`
 - `RegExp` - Preserve comments where the comment body matches a regular expression.
 - `Function` - Preserve comments for which a function returns `true`. The function is called on each comment, gets the comment body as the first argument, and is expected to return a boolean of whether to preserve the comment.
 
+### whitespace
+
+Type: `boolean`<br>
+Default: `true`
+
+Replace comments with whitespace instead of stripping them entirely.
 
 ## Benchmark
 

test.js

@@ -98,8 +98,26 @@ test('main', t => {
 	);
 });
 
-test.failing('strips trailing comment newline', t => {
-	t.is(stripCssComments('/* foo */\n\nbody{}'), '\nbody{}');
-	t.is(stripCssComments('/* foo */\r\n\r\nbody{}'), '\nbody{}');
-	t.is(stripCssComments('/*! foo */\r\n\r\nbody{}'), '/*! foo */\r\n\r\nbody{}');
+test('`whitespace` option', t => {
+	t.is(stripCssComments('/* foo */\n\nbody{}', {whitespace: false}), '\nbody{}');
+	t.is(stripCssComments('/* foo */\r\n\r\nbody{}', {whitespace: false}), '\r\nbody{}');
+	t.is(stripCssComments('/*! foo */\r\n\r\nbody{}', {whitespace: false}), '/*! foo */\r\n\r\nbody{}');
+	t.is(stripCssComments('/*! foo */\r\n\r\nbody{}', {preserve: false, whitespace: false}), '\r\nbody{}');
+
+	t.is(stripCssComments('/*##foo##*/\nbody{}', {preserve: /^##foo##/, whitespace: false}), '/*##foo##*/\nbody{}');
+	t.is(stripCssComments('/*##foo##*/\r\nbody{}', {preserve: /^##foo##/, whitespace: false}), '/*##foo##*/\r\nbody{}');
+
+	t.is(
+		stripCssComments('body{/*!##foo*/\n/*foo*/}', {
+			preserve: comment => comment.endsWith('foo'), whitespace: false
+		}),
+		'body{/*!##foo*/\n/*foo*/}'
+	);
+
+	t.is(
+		stripCssComments('body{/*!##foo*/\r\n/*foo*/}', {
+			preserve: comment => comment.endsWith('foo'), whitespace: false
+		}),
+		'body{/*!##foo*/\r\n/*foo*/}'
+	);
 });