From c5147b7d8df6def1c39d35c3bb9eff71fcc21f87 Mon Sep 17 00:00:00 2001
From: Alex <alexmail87@gmail.com>
Date: Sat, 7 Feb 2026 20:05:15 -0500
Subject: [PATCH] Fix prefetch for links with data-turbo-frame=_self

Prefetching a link `<a href="/" data-turbo-frame="_self"></a>` sends a
request with a header `Turbo-Frame: _self`. This is incorrect as `_self`
should be resolved to the current frame's id.

This change resolves `_self` to the current turbo frame id before
setting the header. When outside of a turbo frame the header is not set.

Fixes #1349
---
 src/observers/link_prefetch_observer.js        |  6 +++++-
 src/tests/fixtures/hover_to_prefetch.html      |  5 +++++
 .../functional/link_prefetch_observer_tests.js | 18 ++++++++++++++++++
 3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/src/observers/link_prefetch_observer.js b/src/observers/link_prefetch_observer.js
index 5f5f66d43..e4dfe864a 100644
--- a/src/observers/link_prefetch_observer.js
+++ b/src/observers/link_prefetch_observer.js
@@ -113,7 +113,11 @@ export class LinkPrefetchObserver {
     request.headers["X-Sec-Purpose"] = "prefetch"
 
     const turboFrame = link.closest("turbo-frame")
-    const turboFrameTarget = link.getAttribute("data-turbo-frame") || turboFrame?.getAttribute("target") || turboFrame?.id
+    let turboFrameTarget = link.getAttribute("data-turbo-frame") || turboFrame?.getAttribute("target") || turboFrame?.id
+
+    if (turboFrameTarget === "_self") {
+      turboFrameTarget = turboFrame?.id
+    }
 
     if (turboFrameTarget && turboFrameTarget !== "_top") {
       request.headers["Turbo-Frame"] = turboFrameTarget
diff --git a/src/tests/fixtures/hover_to_prefetch.html b/src/tests/fixtures/hover_to_prefetch.html
index bd0f6f944..4ba7017ba 100644
--- a/src/tests/fixtures/hover_to_prefetch.html
+++ b/src/tests/fixtures/hover_to_prefetch.html
@@ -56,5 +56,10 @@
     <turbo-frame id="frame_for_prefetch_top" target="_top">
       <a href="/src/tests/fixtures/prefetched.html" id="anchor_for_prefetch_in_frame_target_top">Hover to prefetch me</a>
     </turbo-frame>
+
+    <a href="/src/tests/fixtures/prefetched.html" id="anchor_for_prefetch_out_of_frame_target_self" data-turbo-frame="_self">Hover to prefetch me</a>
+    <turbo-frame id="frame_for_prefetch_self">
+      <a href="/src/tests/fixtures/prefetched.html" id="anchor_for_prefetch_in_frame_target_self" data-turbo-frame="_self">Hover to prefetch me</a>
+    </turbo-frame>
   </body>
 </html>
diff --git a/src/tests/functional/link_prefetch_observer_tests.js b/src/tests/functional/link_prefetch_observer_tests.js
index a40ea16dc..eae2b83a4 100644
--- a/src/tests/functional/link_prefetch_observer_tests.js
+++ b/src/tests/functional/link_prefetch_observer_tests.js
@@ -205,6 +205,24 @@ test("doesn't include a turbo-frame header when the link is inside a turbo frame
   }})
 })
 
+test("includes turbo-frame header when the link with a data-turbo-frame=_self is inside a turbo frame", async ({ page}) => {
+  await goTo({ page, path: "/hover_to_prefetch.html" })
+
+  await assertPrefetchedOnHover({ page, selector: "#anchor_for_prefetch_in_frame_target_self", callback: (request) => {
+    const turboFrameHeader = request.headers()["turbo-frame"]
+    expect(turboFrameHeader).toEqual("frame_for_prefetch_self")
+  }})
+})
+
+test("doesn't include turbo-frame header when the link with a data-turbo-frame=_self is outside of a turbo frame", async ({ page}) => {
+  await goTo({ page, path: "/hover_to_prefetch.html" })
+
+  await assertPrefetchedOnHover({ page, selector: "#anchor_for_prefetch_out_of_frame_target_self", callback: (request) => {
+    const turboFrameHeader = request.headers()["turbo-frame"]
+    expect(turboFrameHeader).toEqual(undefined)
+  }})
+})
+
 test("it prefetches links with a delay", async ({ page }) => {
   await goTo({ page, path: "/hover_to_prefetch.html" })