fix: support textContent swap style for hx-swap-oob (#3563)

swapWithStyle() handled none, outerHTML, afterbegin, beforebegin,
beforeend, afterend, and delete, but had no case for textContent.
Falling through to the default branch caused textContent OOB swaps
to be treated as innerHTML, parsing the response body as HTML
instead of inserting it as literal text.

Mirrors the main-swap textContent handling, which sets
target.textContent directly without parsing as HTML.

Fixes #3563

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: manwithacat

src/htmx.js

@@ -1818,6 +1818,9 @@ var htmx = (function() {
       case 'delete':
         swapDelete(target)
         return
+      case 'textContent':
+        target.textContent = fragment.textContent
+        return
       default:
         var extensions = getExtensions(elt)
         for (let i = 0; i < extensions.length; i++) {

test/attributes/hx-swap-oob.js

@@ -128,6 +128,28 @@ describe('hx-swap-oob attribute', function() {
     byId('d1').innerHTML.should.equal('Swapped5')
   })
 
+  it('handles textContent response properly', function() {
+    this.server.respondWith('GET', '/test', "Clicked<div id='d1' hx-swap-oob='textContent'><h1>Swapped</h1></div>")
+    var div = make('<div hx-get="/test">click me</div>')
+    make('<div id="d1"><span>old</span></div>')
+    div.click()
+    this.server.respond()
+    div.innerHTML.should.equal('Clicked')
+    byId('d1').innerHTML.should.equal('Swapped')
+    byId('d1').textContent.should.equal('Swapped')
+  })
+
+  it('handles textContent oob swap with selector', function() {
+    this.server.respondWith('GET', '/test', "<div>Clicked</div><div hx-swap-oob='textContent:#d1'><em>new</em></div>")
+    var div = make('<div hx-get="/test">click me</div>')
+    make('<div id="d1"><strong>old</strong></div>')
+    div.click()
+    this.server.respond()
+    div.innerHTML.should.equal('<div>Clicked</div>')
+    byId('d1').innerHTML.should.equal('new')
+    byId('d1').textContent.should.equal('new')
+  })
+
   it('oob swaps can be nested in content with config {"allowNestedOobSwaps": true}', function() {
     htmx.config.allowNestedOobSwaps = true
     this.server.respondWith('GET', '/test', "<div>Clicked<div id='d1' foo='bar' hx-swap-oob='innerHTML'>Swapped6</div></div>")