Add trim, preserveLineEndings, and HTML options

index.js

@@ -1,11 +1,86 @@
 /**
- * Collapse white space to a single space.
+ * @typedef {'html'|'js'} Style
+ *
+ * @typedef Options
+ *   Configuration.
+ * @property {Style} [style='js']
+ *   Style of white space to support.
+ * @property {boolean} [preserveLineEndings=false]
+ *   Whether to collapse white space containing a line ending to that line
+ *   ending.
+ *   The default is to collapse to a single space.
+ * @property {boolean} [trim=false]
+ *   Whether to drop white space at the start and end of `value`.
+ *   The default is to keep it.
+ */
+
+const js = /\s+/g
+const html = /[\t\n\v\f\r ]+/g
+
+/**
+ * Collapse white space.
  *
  * @param {string} value
  *   Value to collapse white space in.
+ * @param {Style|Options} [options='js']
+ *   Configuration.
  * @returns {string}
  *   Value with collapsed white space.
  */
-export function collapseWhiteSpace(value) {
-  return String(value).replace(/\s+/g, ' ')
+export function collapseWhiteSpace(value, options) {
+  if (!options) {
+    options = {}
+  } else if (typeof options === 'string') {
+    options = {style: options}
+  }
+
+  const replace = options.preserveLineEndings ? replaceLineEnding : replaceSpace
+
+  return String(value).replace(
+    options.style === 'html' ? html : js,
+    options.trim ? trimFactory(replace) : replace
+  )
+}
+
+/**
+ * Replace white space with a line ending as that line ending and otherwise a
+ * space.
+ *
+ * @param {string} value
+ * @returns {string}
+ */
+function replaceLineEnding(value) {
+  const match = /\r?\n|\r/.exec(value)
+  return match ? match[0] : ' '
+}
+
+/**
+ * Replace white space with a space.
+ *
+ * @returns {string}
+ */
+function replaceSpace() {
+  return ' '
+}
+
+/**
+ * @param {(value: string) => string} replace
+ */
+function trimFactory(replace) {
+  return dropOrReplace
+
+  /**
+   * Replace white space with nothing if it starts or ends the string.
+   * Calls `replace` otherwise.
+   *
+   * @param {string} value
+   * @param {number} index
+   * @param {string} all
+   * @returns {string}
+   */
+  function dropOrReplace(value, index, all) {
+    return index === 0 || index + value.length === all.length
+      ? ''
+      : replace(value)
+  }
 }

package.json

@@ -1,7 +1,7 @@
 {
   "name": "collapse-white-space",
   "version": "2.0.0",
-  "description": "Collapse white space to a single space",
+  "description": "Collapse white space",
   "license": "MIT",
   "keywords": [
     "collapse",

readme.md

@@ -5,21 +5,35 @@
 [![Downloads][downloads-badge]][downloads]
 [![Size][size-badge]][size]
 
-Collapse white space to a single space.
+Collapse white space.
 
 ## Contents
 
+*   [What is this?](#what-is-this)
+*   [When should I use this?](#when-should-i-use-this)
 *   [Install](#install)
 *   [Use](#use)
 *   [API](#api)
-    *   [`collapseWhiteSpace(value)`](#collapsewhitespacevalue)
+    *   [`collapseWhiteSpace(value[, options|style])`](#collapsewhitespacevalue-optionsstyle)
 *   [Types](#types)
 *   [Compatibility](#compatibility)
 *   [Security](#security)
 *   [Related](#related)
 *   [Contribute](#contribute)
 *   [License](#license)
 
+## What is this?
+
+This is a small package that collapses multiple white space characters into one.
+
+## When should I use this?
+
+You can use this package if you want to HTML or JavaScript (default) white space
+to a single character.
+You can optionally drop initial and final white space.
+By default it collapses to a single space, but optionally line endings can be
+preserved.
+
 ## Install
 
 This package is [ESM only][esm].
@@ -56,18 +70,40 @@ collapseWhiteSpace('\tfoo \n\tbar  \t\r\nbaz') //=> ' foo bar baz'
 This package exports the following identifier: `collapseWhiteSpace`.
 There is no default export.
 
-### `collapseWhiteSpace(value)`
+### `collapseWhiteSpace(value[, options|style])`
+
+Collapse white space in `value` (`string`).
+
+##### `style`
+
+Treated as `options.style`.
+
+##### `options`
+
+Configuration.
+
+###### `options.style`
+
+Style of white space to support (`'html'` or `'js'`, default: `'js'`).
+JavaScript white space matches the pattern `\s+`.
+HTML white space matches `[\t\n\v\f\r ]`.
+
+###### `options.preserveLineEndings`
 
-Collapse white space to a single space.
+Whether to collapse white space containing a line ending to that line ending
+(`boolean`, default: `false`).
+The default is to collapse to a single space.
+Line endings matches the pattern `\r?\n|\r`.
 
-###### Parameters
+###### `options.trim`
 
-*   `value` (`string`)
-    – value to collapse white space in
+Whether to drop white space at the start and end of `value` (`boolean`, default:
+`false`).
+The default is to keep it.
 
 ###### Returns
 
-`value` (`string`) – value with collapsed white space.
+`string` – value with collapsed white space.
 
 ## Types
 

test.js

@@ -9,5 +9,34 @@ test('collapseWhiteSpace(value)', function (t) {
   t.equal(collapseWhiteSpace('   bar\t\t\tbaz\n\n\n'), ' bar baz ')
   t.equal(collapseWhiteSpace(' \n bar\t\n\tbaz\r\n'), ' bar baz ')
 
+  t.equal(collapseWhiteSpace(' \u00A0 ', 'js'), ' ', 'style: js')
+  t.equal(collapseWhiteSpace(' \u00A0 ', 'html'), ' \u00A0 ', 'style: html')
+  t.equal(
+    collapseWhiteSpace('a \n b  c', {preserveLineEndings: true}),
+    'a\nb c',
+    '`options.preserveLineEndings: true`'
+  )
+  t.equal(
+    collapseWhiteSpace('a \n b  c', {preserveLineEndings: false}),
+    'a b c',
+    '`options.preserveLineEndings: false`'
+  )
+
+  t.equal(
+    collapseWhiteSpace(' a  b ', {trim: true}),
+    'a b',
+    '`options.trim: true`'
+  )
+  t.equal(
+    collapseWhiteSpace('  ', {trim: true}),
+    '',
+    '`options.trim: true` (2)'
+  )
+  t.equal(
+    collapseWhiteSpace(' a ', {trim: false}),
+    ' a ',
+    '`options.trim: false`'
+  )
+
   t.end()
 })