From d43d78c5b843af401908e1c79fdbbc7b13715e5b Mon Sep 17 00:00:00 2001
From: Henk Poley <HenkPoley@gmail.com>
Date: Thu, 15 Jan 2026 13:21:08 +0100
Subject: [PATCH] Make \Illuminate\Testing\TestResponse::assertHeader() case
 insensitive

I bumped into a PhpUnit error today when asserting the response has the correct header:

```php
$response->assertHeader('content-type', 'text/html; charset=UTF-8');
```

PhpUnit error:

```
Header [content-type] was found, but value [text/html; charset=utf-8] does not match [text/html; charset=UTF-8].
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'text/html; charset=UTF-8'
+'text/html; charset=utf-8'

[..paths omitted..]
```

It might be that `redirect('/some/path')` fairly recently changed from UTF-8 to utf-8 due to HPACK/QPACK normalisation rules. But it broke some of my tests.

In principle these HTTP headers are case-insensitive, so this change to `\Illuminate\Testing\TestResponse::assertHeader()` makes sense.

Let me know if you agree, or you want it fixed in another way.
---
 TestResponse.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/TestResponse.php b/TestResponse.php
index f391bc7..4c5939f 100644
--- a/TestResponse.php
+++ b/TestResponse.php
@@ -373,7 +373,7 @@ public function assertHeader($headerName, $value = null)
         $actual = $this->headers->get($headerName);
 
         if (! is_null($value)) {
-            PHPUnit::withResponse($this)->assertEquals(
+            PHPUnit::withResponse($this)->assertEqualsIgnoringCase(
                 $value, $this->headers->get($headerName),
                 "Header [{$headerName}] was found, but value [{$actual}] does not match [{$value}]."
             );