From a24833b0bf1643b47700f8355b62f033d566a744 Mon Sep 17 00:00:00 2001
From: shail-mehta <shailmehta25@gmail.com>
Date: Sat, 31 Oct 2026 05:08:05 +0000
Subject: [PATCH 1/2] Tests: Cover wp_get_default_extension_for_mime_type().

Add unit tests for known mime-to-extension mapping and unknown mime types.\n\nSee #65819.
---
 .../wpGetDefaultExtensionForMimeType.php      | 48 +++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 tests/phpunit/tests/functions/wpGetDefaultExtensionForMimeType.php

diff --git a/tests/phpunit/tests/functions/wpGetDefaultExtensionForMimeType.php b/tests/phpunit/tests/functions/wpGetDefaultExtensionForMimeType.php
new file mode 100644
index 0000000000000..67fe760b63946
--- /dev/null
+++ b/tests/phpunit/tests/functions/wpGetDefaultExtensionForMimeType.php
@@ -0,0 +1,48 @@
+<?php
+
+/**
+ * Tests for wp_get_default_extension_for_mime_type().
+ *
+ * @group functions
+ *
+ * @covers ::wp_get_default_extension_for_mime_type
+ */
+class Tests_Functions_WpGetDefaultExtensionForMimeType extends WP_UnitTestCase {
+
+	/**
+	 * Tests that known mime types return the first mapped extension.
+	 *
+	 * @ticket 65819
+	 *
+	 * @dataProvider data_known_mime_types
+	 *
+	 * @param string $mime_type Mime type.
+	 * @param string $expected  Expected first extension.
+	 */
+	public function test_returns_first_extension_for_known_mime_type( $mime_type, $expected ) {
+		$this->assertSame( $expected, wp_get_default_extension_for_mime_type( $mime_type ) );
+	}
+
+	/**
+	 * Data provider.
+	 *
+	 * @return array[]
+	 */
+	public static function data_known_mime_types() {
+		return array(
+			'jpeg' => array( 'image/jpeg', 'jpg' ),
+			'png'  => array( 'image/png', 'png' ),
+			'pdf'  => array( 'application/pdf', 'pdf' ),
+			'mp3'  => array( 'audio/mpeg', 'mp3' ),
+		);
+	}
+
+	/**
+	 * Tests that an unknown mime type returns false.
+	 *
+	 * @ticket 65819
+	 */
+	public function test_returns_false_for_unknown_mime_type() {
+		$this->assertFalse( wp_get_default_extension_for_mime_type( 'application/x-not-a-real-type' ) );
+	}
+}

From 437892796830c5a3fe228eeebe7d953cb251553b Mon Sep 17 00:00:00 2001
From: shail-mehta <shailmehta25@gmail.com>
Date: Sun, 1 Nov 2026 05:20:45 +0000
Subject: [PATCH 2/2] Tests: Extend mime default-extension coverage in
 Tests_Functions.

Add PDF and MP3 first-extension assertions to the existing helper test and drop the dedicated class.

See #65819.
---
 tests/phpunit/tests/functions.php             |  4 ++
 .../wpGetDefaultExtensionForMimeType.php      | 48 -------------------
 2 files changed, 4 insertions(+), 48 deletions(-)
 delete mode 100644 tests/phpunit/tests/functions/wpGetDefaultExtensionForMimeType.php

diff --git a/tests/phpunit/tests/functions.php b/tests/phpunit/tests/functions.php
index 9939678366265..4ecbdd81c554f 100644
--- a/tests/phpunit/tests/functions.php
+++ b/tests/phpunit/tests/functions.php
@@ -2265,11 +2265,15 @@ public static function data_wp_is_json_media_type() {
 
 	/**
 	 * @ticket 53668
+	 * @ticket 65819
+	 * @covers ::wp_get_default_extension_for_mime_type
 	 */
 	public function test_wp_get_default_extension_for_mime_type() {
 		$this->assertSame( 'jpg', wp_get_default_extension_for_mime_type( 'image/jpeg' ), 'jpg not returned as default extension for "image/jpeg"' );
 		$this->assertNotSame( 'jpeg', wp_get_default_extension_for_mime_type( 'image/jpeg' ), 'jpeg should not be returned as default extension for "image/jpeg"' );
 		$this->assertSame( 'png', wp_get_default_extension_for_mime_type( 'image/png' ), 'png not returned as default extension for "image/png"' );
+		$this->assertSame( 'pdf', wp_get_default_extension_for_mime_type( 'application/pdf' ), 'pdf not returned as default extension for "application/pdf"' );
+		$this->assertSame( 'mp3', wp_get_default_extension_for_mime_type( 'audio/mpeg' ), 'mp3 not returned as default extension for "audio/mpeg"' );
 		$this->assertFalse( wp_get_default_extension_for_mime_type( 'wibble/wobble' ), 'false not returned for unrecognized mime type' );
 		$this->assertFalse( wp_get_default_extension_for_mime_type( '' ), 'false not returned when empty string as mime type supplied' );
 		$this->assertFalse( wp_get_default_extension_for_mime_type( '   ' ), 'false not returned when empty string as mime type supplied' );
diff --git a/tests/phpunit/tests/functions/wpGetDefaultExtensionForMimeType.php b/tests/phpunit/tests/functions/wpGetDefaultExtensionForMimeType.php
deleted file mode 100644
index 67fe760b63946..0000000000000
--- a/tests/phpunit/tests/functions/wpGetDefaultExtensionForMimeType.php
+++ /dev/null
@@ -1,48 +0,0 @@
-<?php
-
-/**
- * Tests for wp_get_default_extension_for_mime_type().
- *
- * @group functions
- *
- * @covers ::wp_get_default_extension_for_mime_type
- */
-class Tests_Functions_WpGetDefaultExtensionForMimeType extends WP_UnitTestCase {
-
-	/**
-	 * Tests that known mime types return the first mapped extension.
-	 *
-	 * @ticket 65819
-	 *
-	 * @dataProvider data_known_mime_types
-	 *
-	 * @param string $mime_type Mime type.
-	 * @param string $expected  Expected first extension.
-	 */
-	public function test_returns_first_extension_for_known_mime_type( $mime_type, $expected ) {
-		$this->assertSame( $expected, wp_get_default_extension_for_mime_type( $mime_type ) );
-	}
-
-	/**
-	 * Data provider.
-	 *
-	 * @return array[]
-	 */
-	public static function data_known_mime_types() {
-		return array(
-			'jpeg' => array( 'image/jpeg', 'jpg' ),
-			'png'  => array( 'image/png', 'png' ),
-			'pdf'  => array( 'application/pdf', 'pdf' ),
-			'mp3'  => array( 'audio/mpeg', 'mp3' ),
-		);
-	}
-
-	/**
-	 * Tests that an unknown mime type returns false.
-	 *
-	 * @ticket 65819
-	 */
-	public function test_returns_false_for_unknown_mime_type() {
-		$this->assertFalse( wp_get_default_extension_for_mime_type( 'application/x-not-a-real-type' ) );
-	}
-}