diff --git a/tests/phpunit/tests/functions/canonical-charset.php b/tests/phpunit/tests/functions/canonicalCharset.php
similarity index 93%
rename from tests/phpunit/tests/functions/canonical-charset.php
rename to tests/phpunit/tests/functions/canonicalCharset.php
index 107b6d94b9..bd128b769e 100644
--- a/tests/phpunit/tests/functions/canonical-charset.php
+++ b/tests/phpunit/tests/functions/canonicalCharset.php
@@ -1,12 +1,12 @@
 <?php
 
 /*
- * Validate that's badly named charsets always return the correct format for UTF-8 and ISO-8859-1
+ * Validate that badly named charsets always return the correct format for UTF-8 and ISO-8859-1.
  *
  *  @since 4.8.0
  */
 
-class Tests_Functions_canonical_charset extends WP_UnitTestCase {
+class Tests_Functions_CanonicalCharset extends WP_UnitTestCase {
 
 	public function test_utf_8_lower() {
 		$this->assertEquals( 'UTF-8', _canonical_charset( 'utf-8' ) );
diff --git a/tests/phpunit/tests/functions/_cleanup_header_comment.php b/tests/phpunit/tests/functions/cleanupHeaderComment.php
similarity index 97%
rename from tests/phpunit/tests/functions/_cleanup_header_comment.php
rename to tests/phpunit/tests/functions/cleanupHeaderComment.php
index 0f1ceed3b0..825523bf7a 100644
--- a/tests/phpunit/tests/functions/_cleanup_header_comment.php
+++ b/tests/phpunit/tests/functions/cleanupHeaderComment.php
@@ -6,7 +6,7 @@
  * @ticket 8497
  * @ticket 38101
  */
-class Tests_Cleanup_Header_Comment extends WP_UnitTestCase {
+class Tests_Functions_CleanupHeaderComment extends WP_UnitTestCase {
 	/**
 	 * Test cleanup header of header comment.
 	 *
diff --git a/tests/phpunit/tests/functions/deprecated.php b/tests/phpunit/tests/functions/deprecated.php
index 2473972bb4..f42d3daa92 100644
--- a/tests/phpunit/tests/functions/deprecated.php
+++ b/tests/phpunit/tests/functions/deprecated.php
@@ -5,10 +5,10 @@
  *
  * @package    WordPress
  * @subpackage Unit Tests
- * @since      3.5
+ * @since      3.5.0
  * @group      deprecated
  */
-class Test_Functions_Deprecated extends WP_UnitTestCase {
+class Tests_Functions_Deprecated extends WP_UnitTestCase {
 
 	/**
 	 * List of functions that have been passed through _deprecated_function()
diff --git a/tests/phpunit/tests/functions/getStatusHeaderDesc.php b/tests/phpunit/tests/functions/getStatusHeaderDesc.php
index 0b4ec37661..956eae880f 100644
--- a/tests/phpunit/tests/functions/getStatusHeaderDesc.php
+++ b/tests/phpunit/tests/functions/getStatusHeaderDesc.php
@@ -7,7 +7,7 @@
  *
  * @group functions.php
  */
-class Tests_Functions_get_status_header_desc extends WP_UnitTestCase {
+class Tests_Functions_GetStatusHeaderDesc extends WP_UnitTestCase {
 
 	/**
 	 * @dataProvider _status_strings
diff --git a/tests/phpunit/tests/functions/isNewDay.php b/tests/phpunit/tests/functions/isNewDay.php
index 629a6d3de5..0bc459d52c 100644
--- a/tests/phpunit/tests/functions/isNewDay.php
+++ b/tests/phpunit/tests/functions/isNewDay.php
@@ -6,7 +6,7 @@
  *
  * @group functions.php
  */
-class Tests_Functions_is_new_date extends WP_UnitTestCase {
+class Tests_Functions_IsNewDate extends WP_UnitTestCase {
 
 	/**
 	 * @ticket 46627
diff --git a/tests/phpunit/tests/functions/isSerializedString.php b/tests/phpunit/tests/functions/isSerializedString.php
index 292765aab4..9a6bb4f7d7 100644
--- a/tests/phpunit/tests/functions/isSerializedString.php
+++ b/tests/phpunit/tests/functions/isSerializedString.php
@@ -6,7 +6,7 @@
  * @group functions.php
  * @ticket 42870
  */
-class Tests_Functions_Is_Serialized_String extends WP_UnitTestCase {
+class Tests_Functions_IsSerializedString extends WP_UnitTestCase {
 
 	/**
 	 * Data provider method for testing `is_serialized_string()`.
diff --git a/tests/phpunit/tests/functions/numberFormatI18n.php b/tests/phpunit/tests/functions/numberFormatI18n.php
index 8c514b319c..db10ff50a8 100644
--- a/tests/phpunit/tests/functions/numberFormatI18n.php
+++ b/tests/phpunit/tests/functions/numberFormatI18n.php
@@ -6,7 +6,7 @@
  * @group functions.php
  * @group i18n
  */
-class Tests_Functions_Number_Format_I18n extends WP_UnitTestCase {
+class Tests_Functions_NumberFormatI18n extends WP_UnitTestCase {
 	public function test_should_fall_back_to_number_format_when_wp_locale_is_not_set() {
 		$locale               = clone $GLOBALS['wp_locale'];
 		$GLOBALS['wp_locale'] = null;
diff --git a/tests/phpunit/tests/functions/pluginBasename.php b/tests/phpunit/tests/functions/pluginBasename.php
index 42755f5f25..e664d8fbd6 100644
--- a/tests/phpunit/tests/functions/pluginBasename.php
+++ b/tests/phpunit/tests/functions/pluginBasename.php
@@ -6,7 +6,7 @@
  * @group functions.php
  * @group plugins
  */
-class Tests_Plugin_Basename extends WP_UnitTestCase {
+class Tests_Functions_PluginBasename extends WP_UnitTestCase {
 
 	/**
 	 * @var array
diff --git a/tests/phpunit/tests/functions/sizeFormat.php b/tests/phpunit/tests/functions/sizeFormat.php
index 0cf26511f1..7d473f23b9 100644
--- a/tests/phpunit/tests/functions/sizeFormat.php
+++ b/tests/phpunit/tests/functions/sizeFormat.php
@@ -6,7 +6,7 @@
  * @group functions.php
  * @ticket 36635
  */
-class Tests_Functions_Size_Format extends WP_UnitTestCase {
+class Tests_Functions_SizeFormat extends WP_UnitTestCase {
 	public function _data_size_format() {
 		return array(
 			array( array(), 0, false ),
diff --git a/tests/phpunit/tests/functions/underscoreReturn.php b/tests/phpunit/tests/functions/underscoreReturn.php
index 8c1d2e0962..40222633f8 100644
--- a/tests/phpunit/tests/functions/underscoreReturn.php
+++ b/tests/phpunit/tests/functions/underscoreReturn.php
@@ -6,7 +6,7 @@
  *
  * @group functions.php
  */
-class Tests_Functions_Underscore_Return extends WP_UnitTestCase {
+class Tests_Functions_UnderscoreReturn extends WP_UnitTestCase {
 
 	public function test__return_true() {
 		$this->assertTrue( __return_true() );
diff --git a/tests/phpunit/tests/functions/wpArraySliceAssoc.php b/tests/phpunit/tests/functions/wpArraySliceAssoc.php
index 73df5cb87c..bedf731771 100644
--- a/tests/phpunit/tests/functions/wpArraySliceAssoc.php
+++ b/tests/phpunit/tests/functions/wpArraySliceAssoc.php
@@ -8,7 +8,7 @@
  * @covers wp_array_slice_assoc
  * @group functions.php
  */
-class Tests_Functions_WpArraySliceAssoc extends WP_UnitTestCase {
+class Tests_Functions_wpArraySliceAssoc extends WP_UnitTestCase {
 
 	/**
 	 * Test wp_array_slice_assoc().
diff --git a/tests/phpunit/tests/functions/wpAuthCheck.php b/tests/phpunit/tests/functions/wpAuthCheck.php
index 32aafdddb1..a583d01606 100644
--- a/tests/phpunit/tests/functions/wpAuthCheck.php
+++ b/tests/phpunit/tests/functions/wpAuthCheck.php
@@ -5,7 +5,7 @@
  *
  * @group functions.php
  */
-class Tests_Functions_WP_Auth_Check extends WP_UnitTestCase {
+class Tests_Functions_wpAuthCheck extends WP_UnitTestCase {
 
 	/**
 	 * Run with user not logged in.
diff --git a/tests/phpunit/tests/functions/getArchives.php b/tests/phpunit/tests/functions/wpGetArchives.php
similarity index 98%
rename from tests/phpunit/tests/functions/getArchives.php
rename to tests/phpunit/tests/functions/wpGetArchives.php
index c771eece09..7eaf356b06 100644
--- a/tests/phpunit/tests/functions/getArchives.php
+++ b/tests/phpunit/tests/functions/wpGetArchives.php
@@ -7,7 +7,7 @@ $defaults = array(
 	'echo' => 1, 'order' => 'DESC',
 );
 */
-class Tests_Get_Archives extends WP_UnitTestCase {
+class Tests_Functions_wpGetArchives extends WP_UnitTestCase {
 	protected static $post_ids;
 	protected $month_url;
 	protected $year_url;
diff --git a/tests/phpunit/tests/functions/wpGetMimeTypes.php b/tests/phpunit/tests/functions/wpGetMimeTypes.php
index dec3ea73d6..8188ecd518 100644
--- a/tests/phpunit/tests/functions/wpGetMimeTypes.php
+++ b/tests/phpunit/tests/functions/wpGetMimeTypes.php
@@ -5,7 +5,7 @@
  *
  * @group functions.php
  */
-class Tests_wp_get_mime_types extends WP_UnitTestCase {
+class Tests_Functions_wpGetMimeTypes extends WP_UnitTestCase {
 
 	/**
 	 * @ticket 47701
diff --git a/tests/phpunit/tests/functions/listFilter.php b/tests/phpunit/tests/functions/wpListFilter.php
similarity index 99%
rename from tests/phpunit/tests/functions/listFilter.php
rename to tests/phpunit/tests/functions/wpListFilter.php
index 1e5c553357..4708cea16f 100644
--- a/tests/phpunit/tests/functions/listFilter.php
+++ b/tests/phpunit/tests/functions/wpListFilter.php
@@ -5,7 +5,7 @@
  *
  * @group functions.php
  */
-class Tests_Functions_ListFilter extends WP_UnitTestCase {
+class Tests_Functions_wpListFilter extends WP_UnitTestCase {
 	var $object_list = array();
 	var $array_list  = array();
 
diff --git a/tests/phpunit/tests/functions/wpListUtil.php b/tests/phpunit/tests/functions/wpListUtil.php
index ef7ac45620..d6a014357c 100644
--- a/tests/phpunit/tests/functions/wpListUtil.php
+++ b/tests/phpunit/tests/functions/wpListUtil.php
@@ -3,7 +3,8 @@
 /**
  * @group functions.php
  */
-class Tests_WP_List_Util extends WP_UnitTestCase {
+class Tests_Functions_wpListUtil extends WP_UnitTestCase {
+
 	public function data_test_wp_list_pluck() {
 		return array(
 			'arrays'                         => array(
diff --git a/tests/phpunit/tests/functions/wpRemoteFopen.php b/tests/phpunit/tests/functions/wpRemoteFopen.php
index b5627da800..3d52b82ba1 100644
--- a/tests/phpunit/tests/functions/wpRemoteFopen.php
+++ b/tests/phpunit/tests/functions/wpRemoteFopen.php
@@ -4,7 +4,7 @@
  * @group external-http
  * @group functions.php
  */
-class Tests_Functions_wp_remote_fopen extends WP_UnitTestCase {
+class Tests_Functions_wpRemoteFopen extends WP_UnitTestCase {
 
 	/**
 	 * @ticket 48845
diff --git a/tests/phpunit/tests/functions/wpValidateBoolean.php b/tests/phpunit/tests/functions/wpValidateBoolean.php
index 833b731425..848bccf236 100644
--- a/tests/phpunit/tests/functions/wpValidateBoolean.php
+++ b/tests/phpunit/tests/functions/wpValidateBoolean.php
@@ -6,7 +6,7 @@
  * @covers ::wp_validate_boolean
  * @group functions.php
  */
-class Tests_Functions_WpValidateBoolean extends WP_UnitTestCase {
+class Tests_Functions_wpValidateBoolean extends WP_UnitTestCase {
 	/**
 	 * Provides test scenarios for all possible scenarios in wp_validate_boolean().
 	 *