fix(content): also trim leading/trailing   whitespace

spec/content.spec.js

@@ -626,6 +626,82 @@ describe('Content', function () {
       expect(result).to.equal('ac')
     })
 
+    describe('trim leading white space', function () {
+      it('removes single regular whitespace', function () {
+        const element = createElement('<div> hello world</div>')
+        const result = content.extractContent(element)
+        expect(result).to.equal('hello world')
+      })
+
+      it('removes multiple regular whitespaces', function () {
+        const element = createElement('<div>   hello world</div>')
+        const result = content.extractContent(element)
+        expect(result).to.equal('hello world')
+      })
+
+      it('removes &nbsp;', function () {
+        const element = createElement('<div>&nbsp; &nbsp;hello world</div>')
+        const result = content.extractContent(element)
+        expect(result).to.equal('hello world')
+      })
+
+      it('removes multiple regular whitespaces before tag', function () {
+        const element = createElement('<div>   <strong>hello world</strong></div>')
+        const result = content.extractContent(element)
+        expect(result).to.equal('<strong>hello world</strong>')
+      })
+
+      it('removes &nbsp; before tag', function () {
+        const element = createElement('<div>&nbsp;<strong>hello world</strong></div>')
+        const result = content.extractContent(element)
+        expect(result).to.equal('<strong>hello world</strong>')
+      })
+
+      it('keeps whitespace within tag', function () {
+        const element = createElement('<div>&nbsp;<strong> hello world</strong></div>')
+        const result = content.extractContent(element)
+        expect(result).to.equal('<strong> hello world</strong>')
+      })
+    })
+
+    describe('trim trailing white space', function () {
+      it('removes single regular whitespace', function () {
+        const element = createElement('<div>hello world </div>')
+        const result = content.extractContent(element)
+        expect(result).to.equal('hello world')
+      })
+
+      it('removes multiple regular whitespaces', function () {
+        const element = createElement('<div>hello world   </div>')
+        const result = content.extractContent(element)
+        expect(result).to.equal('hello world')
+      })
+
+      it('removes &nbsp;', function () {
+        const element = createElement('<div>hello world&nbsp; &nbsp;</div>')
+        const result = content.extractContent(element)
+        expect(result).to.equal('hello world')
+      })
+
+      it('removes multiple regular whitespaces after tag', function () {
+        const element = createElement('<div><strong>hello world</strong>   </div>')
+        const result = content.extractContent(element)
+        expect(result).to.equal('<strong>hello world</strong>')
+      })
+
+      it('removes &nbsp; after tag', function () {
+        const element = createElement('<div><strong>hello world</strong>&nbsp;</div>')
+        const result = content.extractContent(element)
+        expect(result).to.equal('<strong>hello world</strong>')
+      })
+
+      it('keeps whitespace within tag', function () {
+        const element = createElement('<div><strong>hello world </strong>&nbsp;</div>')
+        const result = content.extractContent(element)
+        expect(result).to.equal('<strong>hello world </strong>')
+      })
+    })
+
     describe('called with keepUiElements', function () {
 
       it('does not unwrap a "ui-unwrap" span', function () {

src/content.js

@@ -15,6 +15,10 @@ const zeroWidthSpace = /\u200B/g
 const zeroWidthNonBreakingSpace = /\uFEFF/g
 const whitespaceExceptSpace = /[^\S ]/g
 
+const everythingWhitespace = /^\s+$/
+const leadingWhitespace = /^\s+/
+const trailingWhitespace = /\s+$/
+
 // Clean up the Html.
 export function tidyHtml (element) {
   // if (element.normalize) element.normalize()
@@ -143,25 +147,34 @@ export function cloneRangeContents (range) {
 
 function removeWhitespaces (node, type, firstCall = true) {
   let elem
+  // loop through all children:
+  // from left to right if type = 'firstChild',
+  // from right to left if type = 'lastChild'
   while ((elem = node[type])) {
     if (elem.nodeType === nodeType.textNode) {
-      if (/^\s+$/.test(elem.textContent)) node.removeChild(elem)
+      // Just remove text nodes if they consist only of whitespace
+      if (everythingWhitespace.test(elem.textContent)) node.removeChild(elem)
       else break
     } else if (elem.nodeName === 'BR') {
       elem.remove()
     } else {
+      // For element nodes (e.g. <strong> tags), we repeat the logic recursively
+      // to remove empty text nodes or <br> tags.
       if (elem[type]) removeWhitespaces(elem, type, false)
       break
     }
   }
 
+  // Text nodes with leading/trailing whitespace can be trimmed if config allows.
+  // We only do it to the outermost text node. Once a text was wrapped in
+  // another element, we preserve the whitespace.
   if (!firstCall) return
   elem = node[type]
   if (elem?.nodeType !== nodeType.textNode) return
   // Remove whitespaces at the end or start of a block with content
   //   e.g. '  Hello world' > 'Hello World'
   if (config.trimLeadingAndTrailingWhitespaces) {
-    elem.textContent = elem.textContent.replace(type.startsWith('last') ? / +$/ : /^ +/, '')
+    elem.textContent = elem.textContent.replace(type.startsWith('last') ? trailingWhitespace : leadingWhitespace, '')
   }
 }