diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index 8e8a0fb2f09215..4a4c9bf6569356 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -14,6 +14,7 @@
 	<testsuites>
 		<testsuite name="default">
 			<directory suffix="-test.php">./phpunit/</directory>
+			<directory suffix=".php">./phpunit/tests/</directory>
 		</testsuite>
 	</testsuites>
 	<groups>
diff --git a/phpunit/bootstrap.php b/phpunit/bootstrap.php
index f64e6fa5c7ef14..7084df68443baa 100644
--- a/phpunit/bootstrap.php
+++ b/phpunit/bootstrap.php
@@ -21,6 +21,8 @@
 if ( ! defined( 'LOCAL_WP_ENVIRONMENT_TYPE' ) ) {
 	define( 'LOCAL_WP_ENVIRONMENT_TYPE', 'local' );
 }
+define( 'GUTENBERG_DIR_TESTDATA', __DIR__ . '/data/' );
+define( 'GUTENBERG_DIR_TESTFIXTURES', __DIR__ . '/fixtures/' );
 
 // Pretend that these are Core unit tests. This is needed so that
 // wp_theme_has_theme_json() does not cache its return value between each test.
diff --git a/phpunit/multisite.xml b/phpunit/multisite.xml
index 03b0b5314bc507..ac18402abb0c82 100644
--- a/phpunit/multisite.xml
+++ b/phpunit/multisite.xml
@@ -15,6 +15,7 @@
 	<testsuites>
 		<testsuite name="default">
 			<directory suffix="-test.php">./</directory>
+			<directory suffix=".php">./tests/</directory>
 		</testsuite>
 	</testsuites>
 	<groups>
diff --git a/phpunit/fonts-api/wp-fonts-testcase.php b/phpunit/tests/fonts-api/base.php
similarity index 99%
rename from phpunit/fonts-api/wp-fonts-testcase.php
rename to phpunit/tests/fonts-api/base.php
index b7bff9234b9ed0..11ae3b624ea8ca 100644
--- a/phpunit/fonts-api/wp-fonts-testcase.php
+++ b/phpunit/tests/fonts-api/base.php
@@ -70,7 +70,7 @@ public static function set_up_before_class() {
 		parent::set_up_before_class();
 
 		if ( self::$requires_switch_theme_fixtures ) {
-			self::$theme_root = realpath( __DIR__ . '/../data/themedir1' );
+			self::$theme_root = realpath( GUTENBERG_DIR_TESTDATA . '/themedir1' );
 		}
 	}
 
diff --git a/phpunit/fonts-api/bc-layer/fonts-bc-layer-testcase.php b/phpunit/tests/fonts-api/bc-layer/base.php
similarity index 94%
rename from phpunit/fonts-api/bc-layer/fonts-bc-layer-testcase.php
rename to phpunit/tests/fonts-api/bc-layer/base.php
index 6c5e3bad800b8e..27a4d43f7188a2 100644
--- a/phpunit/fonts-api/bc-layer/fonts-bc-layer-testcase.php
+++ b/phpunit/tests/fonts-api/bc-layer/base.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 require_once __DIR__ . '/bc-layer-tests-dataset.php';
 
 /**
diff --git a/phpunit/fonts-api/bc-layer/bc-layer-tests-dataset.php b/phpunit/tests/fonts-api/bc-layer/bc-layer-tests-dataset.php
similarity index 100%
rename from phpunit/fonts-api/bc-layer/bc-layer-tests-dataset.php
rename to phpunit/tests/fonts-api/bc-layer/bc-layer-tests-dataset.php
diff --git a/phpunit/fonts-api/bc-layer/gutenbergFontsApiBcLayer/isDeprecatedStructure-test.php b/phpunit/tests/fonts-api/bc-layer/gutenbergFontsApiBcLayer/isDeprecatedStructure.php
similarity index 94%
rename from phpunit/fonts-api/bc-layer/gutenbergFontsApiBcLayer/isDeprecatedStructure-test.php
rename to phpunit/tests/fonts-api/bc-layer/gutenbergFontsApiBcLayer/isDeprecatedStructure.php
index e623ecf19f7d13..d76de3f205005d 100644
--- a/phpunit/fonts-api/bc-layer/gutenbergFontsApiBcLayer/isDeprecatedStructure-test.php
+++ b/phpunit/tests/fonts-api/bc-layer/gutenbergFontsApiBcLayer/isDeprecatedStructure.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../fonts-bc-layer-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/bc-layer/gutenbergFontsApiBcLayer/migrateDeprecatedStructure-test.php b/phpunit/tests/fonts-api/bc-layer/gutenbergFontsApiBcLayer/migrateDeprecatedStructure.php
similarity index 95%
rename from phpunit/fonts-api/bc-layer/gutenbergFontsApiBcLayer/migrateDeprecatedStructure-test.php
rename to phpunit/tests/fonts-api/bc-layer/gutenbergFontsApiBcLayer/migrateDeprecatedStructure.php
index c0e2c77d9ca1c2..b98481dfbf942f 100644
--- a/phpunit/fonts-api/bc-layer/gutenbergFontsApiBcLayer/migrateDeprecatedStructure-test.php
+++ b/phpunit/tests/fonts-api/bc-layer/gutenbergFontsApiBcLayer/migrateDeprecatedStructure.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../fonts-bc-layer-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/bc-layer/wpRegisterWebfonts-test.php b/phpunit/tests/fonts-api/bc-layer/wpRegisterWebfonts.php
similarity index 97%
rename from phpunit/fonts-api/bc-layer/wpRegisterWebfonts-test.php
rename to phpunit/tests/fonts-api/bc-layer/wpRegisterWebfonts.php
index 4a64068fee8c86..59e0a9d314a135 100644
--- a/phpunit/fonts-api/bc-layer/wpRegisterWebfonts-test.php
+++ b/phpunit/tests/fonts-api/bc-layer/wpRegisterWebfonts.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/fonts-bc-layer-testcase.php';
+require_once __DIR__ . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/bc-layer/wpWebfonts/getAllWebfonts-test.php b/phpunit/tests/fonts-api/bc-layer/wpWebfonts/getAllWebfonts.php
similarity index 93%
rename from phpunit/fonts-api/bc-layer/wpWebfonts/getAllWebfonts-test.php
rename to phpunit/tests/fonts-api/bc-layer/wpWebfonts/getAllWebfonts.php
index d6c1e10b691e4a..7a217a343c5359 100644
--- a/phpunit/fonts-api/bc-layer/wpWebfonts/getAllWebfonts-test.php
+++ b/phpunit/tests/fonts-api/bc-layer/wpWebfonts/getAllWebfonts.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/bc-layer/wpWebfonts/getFontSlug-test.php b/phpunit/tests/fonts-api/bc-layer/wpWebfonts/getFontSlug.php
similarity index 98%
rename from phpunit/fonts-api/bc-layer/wpWebfonts/getFontSlug-test.php
rename to phpunit/tests/fonts-api/bc-layer/wpWebfonts/getFontSlug.php
index df17cb69b621c4..7c05f24b037520 100644
--- a/phpunit/fonts-api/bc-layer/wpWebfonts/getFontSlug-test.php
+++ b/phpunit/tests/fonts-api/bc-layer/wpWebfonts/getFontSlug.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../fonts-bc-layer-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/bc-layer/wpWebfonts/getRegisteredWebfonts-test.php b/phpunit/tests/fonts-api/bc-layer/wpWebfonts/getRegisteredWebfonts.php
similarity index 93%
rename from phpunit/fonts-api/bc-layer/wpWebfonts/getRegisteredWebfonts-test.php
rename to phpunit/tests/fonts-api/bc-layer/wpWebfonts/getRegisteredWebfonts.php
index 3b41d9d37b4147..7a8c97a4d86471 100644
--- a/phpunit/fonts-api/bc-layer/wpWebfonts/getRegisteredWebfonts-test.php
+++ b/phpunit/tests/fonts-api/bc-layer/wpWebfonts/getRegisteredWebfonts.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../fonts-bc-layer-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/bc-layer/wpWebfonts/registerWebfont-test.php b/phpunit/tests/fonts-api/bc-layer/wpWebfonts/registerWebfont.php
similarity index 98%
rename from phpunit/fonts-api/bc-layer/wpWebfonts/registerWebfont-test.php
rename to phpunit/tests/fonts-api/bc-layer/wpWebfonts/registerWebfont.php
index faaaf0e7ef6b79..ccc4249ad4fcc6 100644
--- a/phpunit/fonts-api/bc-layer/wpWebfonts/registerWebfont-test.php
+++ b/phpunit/tests/fonts-api/bc-layer/wpWebfonts/registerWebfont.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../fonts-bc-layer-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wp-fonts-tests-dataset.php b/phpunit/tests/fonts-api/wp-fonts-tests-dataset.php
similarity index 100%
rename from phpunit/fonts-api/wp-fonts-tests-dataset.php
rename to phpunit/tests/fonts-api/wp-fonts-tests-dataset.php
diff --git a/phpunit/fonts-api/wpDeregisterFontFamily-test.php b/phpunit/tests/fonts-api/wpDeregisterFontFamily.php
similarity index 98%
rename from phpunit/fonts-api/wpDeregisterFontFamily-test.php
rename to phpunit/tests/fonts-api/wpDeregisterFontFamily.php
index 6ef73879f20320..59db2e2abc8264 100644
--- a/phpunit/fonts-api/wpDeregisterFontFamily-test.php
+++ b/phpunit/tests/fonts-api/wpDeregisterFontFamily.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/wp-fonts-testcase.php';
+require_once __DIR__ . '/base.php';
 
 /**
  * @group fontsapi
diff --git a/phpunit/fonts-api/wpDeregisterFontVariation-test.php b/phpunit/tests/fonts-api/wpDeregisterFontVariation.php
similarity index 99%
rename from phpunit/fonts-api/wpDeregisterFontVariation-test.php
rename to phpunit/tests/fonts-api/wpDeregisterFontVariation.php
index 5cf20301c12702..78b4bf51f758af 100644
--- a/phpunit/fonts-api/wpDeregisterFontVariation-test.php
+++ b/phpunit/tests/fonts-api/wpDeregisterFontVariation.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/wp-fonts-testcase.php';
+require_once __DIR__ . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpEnqueueFontVariations-test.php b/phpunit/tests/fonts-api/wpEnqueueFontVariations.php
similarity index 98%
rename from phpunit/fonts-api/wpEnqueueFontVariations-test.php
rename to phpunit/tests/fonts-api/wpEnqueueFontVariations.php
index 46aa4fd1499d17..6e026d99f58897 100644
--- a/phpunit/fonts-api/wpEnqueueFontVariations-test.php
+++ b/phpunit/tests/fonts-api/wpEnqueueFontVariations.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/wp-fonts-testcase.php';
+require_once __DIR__ . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpEnqueueFonts-test.php b/phpunit/tests/fonts-api/wpEnqueueFonts.php
similarity index 98%
rename from phpunit/fonts-api/wpEnqueueFonts-test.php
rename to phpunit/tests/fonts-api/wpEnqueueFonts.php
index 43c1fd63a76104..c00fb0f2dfdae5 100644
--- a/phpunit/fonts-api/wpEnqueueFonts-test.php
+++ b/phpunit/tests/fonts-api/wpEnqueueFonts.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/wp-fonts-testcase.php';
+require_once __DIR__ . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts-test.php b/phpunit/tests/fonts-api/wpFonts.php
similarity index 94%
rename from phpunit/fonts-api/wpFonts-test.php
rename to phpunit/tests/fonts-api/wpFonts.php
index 9a50dcb0fafc30..3b33e58edf2995 100644
--- a/phpunit/fonts-api/wpFonts-test.php
+++ b/phpunit/tests/fonts-api/wpFonts.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/wp-fonts-testcase.php';
+require_once __DIR__ . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/add-test.php b/phpunit/tests/fonts-api/wpFonts/add.php
similarity index 95%
rename from phpunit/fonts-api/wpFonts/add-test.php
rename to phpunit/tests/fonts-api/wpFonts/add.php
index 8d88b6834d0cf6..f9449b87c53b53 100644
--- a/phpunit/fonts-api/wpFonts/add-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/add.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/addFontFamily-test.php b/phpunit/tests/fonts-api/wpFonts/addFontFamily.php
similarity index 97%
rename from phpunit/fonts-api/wpFonts/addFontFamily-test.php
rename to phpunit/tests/fonts-api/wpFonts/addFontFamily.php
index 85676b47c35e5e..f227c2c4025a40 100644
--- a/phpunit/fonts-api/wpFonts/addFontFamily-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/addFontFamily.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/addVariation-test.php b/phpunit/tests/fonts-api/wpFonts/addVariation.php
similarity index 99%
rename from phpunit/fonts-api/wpFonts/addVariation-test.php
rename to phpunit/tests/fonts-api/wpFonts/addVariation.php
index 0f86c07ab0eaa8..5b6d93bcc99fe0 100644
--- a/phpunit/fonts-api/wpFonts/addVariation-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/addVariation.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/dequeue-test.php b/phpunit/tests/fonts-api/wpFonts/dequeue.php
similarity index 97%
rename from phpunit/fonts-api/wpFonts/dequeue-test.php
rename to phpunit/tests/fonts-api/wpFonts/dequeue.php
index e6ea2223657baa..6cd11dc55b9376 100644
--- a/phpunit/fonts-api/wpFonts/dequeue-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/dequeue.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/doItem-test.php b/phpunit/tests/fonts-api/wpFonts/doItem.php
similarity index 99%
rename from phpunit/fonts-api/wpFonts/doItem-test.php
rename to phpunit/tests/fonts-api/wpFonts/doItem.php
index 602c8d74e1bae1..af46f376b3bc5c 100644
--- a/phpunit/fonts-api/wpFonts/doItem-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/doItem.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/doItems-test.php b/phpunit/tests/fonts-api/wpFonts/doItems.php
similarity index 98%
rename from phpunit/fonts-api/wpFonts/doItems-test.php
rename to phpunit/tests/fonts-api/wpFonts/doItems.php
index 20314f957014d9..23307366101cb0 100644
--- a/phpunit/fonts-api/wpFonts/doItems-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/doItems.php
@@ -6,8 +6,8 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
-require_once __DIR__ . '/../../fixtures/mock-provider.php';
+require_once dirname( __DIR__ ) . '/base.php';
+require_once GUTENBERG_DIR_TESTFIXTURES . '/mock-provider.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/enqueue-test.php b/phpunit/tests/fonts-api/wpFonts/enqueue.php
similarity index 97%
rename from phpunit/fonts-api/wpFonts/enqueue-test.php
rename to phpunit/tests/fonts-api/wpFonts/enqueue.php
index 34380febfef5df..09c14676c7ae09 100644
--- a/phpunit/fonts-api/wpFonts/enqueue-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/enqueue.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/getEnqueued-test.php b/phpunit/tests/fonts-api/wpFonts/getEnqueued.php
similarity index 96%
rename from phpunit/fonts-api/wpFonts/getEnqueued-test.php
rename to phpunit/tests/fonts-api/wpFonts/getEnqueued.php
index 68a509f3c35ccb..bacb8a31aa6500 100644
--- a/phpunit/fonts-api/wpFonts/getEnqueued-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/getEnqueued.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/getProviders-test.php b/phpunit/tests/fonts-api/wpFonts/getProviders.php
similarity index 93%
rename from phpunit/fonts-api/wpFonts/getProviders-test.php
rename to phpunit/tests/fonts-api/wpFonts/getProviders.php
index ed73921a31aea4..410adaace286aa 100644
--- a/phpunit/fonts-api/wpFonts/getProviders-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/getProviders.php
@@ -6,8 +6,8 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
-require_once __DIR__ . '/../../fixtures/mock-provider.php';
+require_once dirname( __DIR__ ) . '/base.php';
+require_once GUTENBERG_DIR_TESTFIXTURES . '/mock-provider.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/getRegistered-test.php b/phpunit/tests/fonts-api/wpFonts/getRegistered.php
similarity index 97%
rename from phpunit/fonts-api/wpFonts/getRegistered-test.php
rename to phpunit/tests/fonts-api/wpFonts/getRegistered.php
index 365a97733f3cfa..7dc116f5875390 100644
--- a/phpunit/fonts-api/wpFonts/getRegistered-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/getRegistered.php
@@ -7,7 +7,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/query-test.php b/phpunit/tests/fonts-api/wpFonts/query.php
similarity index 98%
rename from phpunit/fonts-api/wpFonts/query-test.php
rename to phpunit/tests/fonts-api/wpFonts/query.php
index c64d88cf9fa867..0e56b515e7ebf4 100644
--- a/phpunit/fonts-api/wpFonts/query-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/query.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/registerProvider-test.php b/phpunit/tests/fonts-api/wpFonts/registerProvider.php
similarity index 96%
rename from phpunit/fonts-api/wpFonts/registerProvider-test.php
rename to phpunit/tests/fonts-api/wpFonts/registerProvider.php
index 03dc6fd6049b1a..09d3d7f3891720 100644
--- a/phpunit/fonts-api/wpFonts/registerProvider-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/registerProvider.php
@@ -6,8 +6,8 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
-require_once __DIR__ . '/../../fixtures/mock-provider.php';
+require_once dirname( __DIR__ ) . '/base.php';
+require_once GUTENBERG_DIR_TESTFIXTURES . '/mock-provider.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/remove-test.php b/phpunit/tests/fonts-api/wpFonts/remove.php
similarity index 97%
rename from phpunit/fonts-api/wpFonts/remove-test.php
rename to phpunit/tests/fonts-api/wpFonts/remove.php
index 6da419a988e853..208bd58c3d2c30 100644
--- a/phpunit/fonts-api/wpFonts/remove-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/remove.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFonts/removeFontFamily-test.php b/phpunit/tests/fonts-api/wpFonts/removeFontFamily.php
similarity index 98%
rename from phpunit/fonts-api/wpFonts/removeFontFamily-test.php
rename to phpunit/tests/fonts-api/wpFonts/removeFontFamily.php
index b04882e04acdde..6e762307d05207 100644
--- a/phpunit/fonts-api/wpFonts/removeFontFamily-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/removeFontFamily.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group fontsapi
diff --git a/phpunit/fonts-api/wpFonts/removeVariation-test.php b/phpunit/tests/fonts-api/wpFonts/removeVariation.php
similarity index 99%
rename from phpunit/fonts-api/wpFonts/removeVariation-test.php
rename to phpunit/tests/fonts-api/wpFonts/removeVariation.php
index fb8f78e4122fb2..508c8ce264d8fb 100644
--- a/phpunit/fonts-api/wpFonts/removeVariation-test.php
+++ b/phpunit/tests/fonts-api/wpFonts/removeVariation.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFontsProviderLocal-test.php b/phpunit/tests/fonts-api/wpFontsProviderLocal.php
similarity index 97%
rename from phpunit/fonts-api/wpFontsProviderLocal-test.php
rename to phpunit/tests/fonts-api/wpFontsProviderLocal.php
index 1bd28e4a6aba7b..f9319390c3b6b5 100644
--- a/phpunit/fonts-api/wpFontsProviderLocal-test.php
+++ b/phpunit/tests/fonts-api/wpFontsProviderLocal.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/wp-fonts-testcase.php';
+require_once __DIR__ . '/base.php';
 
 /**
  * @group fontsapi
@@ -155,7 +155,7 @@ public function data_get_css_print_styles() {
 	 * `wp-content/themes/` directory to ensure consistency when running tests.
 	 */
 	private function set_up_theme() {
-		$this->theme_root                = realpath( DIR_TESTDATA . '/themedir1' );
+		$this->theme_root                = realpath( GUTENBERG_DIR_TESTDATA . '/themedir1' );
 		$this->orig_theme_dir            = $GLOBALS['wp_theme_directories'];
 		$GLOBALS['wp_theme_directories'] = array( $this->theme_root );
 
diff --git a/phpunit/fonts-api/wpFontsResolver/addMissingFontsToThemeJson-test.php b/phpunit/tests/fonts-api/wpFontsResolver/addMissingFontsToThemeJson.php
similarity index 99%
rename from phpunit/fonts-api/wpFontsResolver/addMissingFontsToThemeJson-test.php
rename to phpunit/tests/fonts-api/wpFontsResolver/addMissingFontsToThemeJson.php
index 31bb4b1d409cc4..d6e45561e5e335 100644
--- a/phpunit/fonts-api/wpFontsResolver/addMissingFontsToThemeJson-test.php
+++ b/phpunit/tests/fonts-api/wpFontsResolver/addMissingFontsToThemeJson.php
@@ -1,6 +1,6 @@
 <?php
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * Test WP_Fonts_Resolver::add_missing_fonts_to_theme_json().
diff --git a/phpunit/fonts-api/wpFontsResolver/enqueueUserSelectedFonts-test.php b/phpunit/tests/fonts-api/wpFontsResolver/enqueueUserSelectedFonts.php
similarity index 98%
rename from phpunit/fonts-api/wpFontsResolver/enqueueUserSelectedFonts-test.php
rename to phpunit/tests/fonts-api/wpFontsResolver/enqueueUserSelectedFonts.php
index c3ba0fd1f72ac6..9ff01f1c3166cd 100644
--- a/phpunit/fonts-api/wpFontsResolver/enqueueUserSelectedFonts-test.php
+++ b/phpunit/tests/fonts-api/wpFontsResolver/enqueueUserSelectedFonts.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpFontsResolver/registerFontsFromThemeJson-test.php b/phpunit/tests/fonts-api/wpFontsResolver/registerFontsFromThemeJson.php
similarity index 99%
rename from phpunit/fonts-api/wpFontsResolver/registerFontsFromThemeJson-test.php
rename to phpunit/tests/fonts-api/wpFontsResolver/registerFontsFromThemeJson.php
index c3bedd9e63e9e6..c812b98d3d156d 100644
--- a/phpunit/fonts-api/wpFontsResolver/registerFontsFromThemeJson-test.php
+++ b/phpunit/tests/fonts-api/wpFontsResolver/registerFontsFromThemeJson.php
@@ -1,6 +1,6 @@
 <?php
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * Test WP_Fonts_Resolver::register_fonts_from_theme_json().
diff --git a/phpunit/fonts-api/wpFontsUtils/convertFontFamilyIntoHandle-test.php b/phpunit/tests/fonts-api/wpFontsUtils/convertFontFamilyIntoHandle.php
similarity index 97%
rename from phpunit/fonts-api/wpFontsUtils/convertFontFamilyIntoHandle-test.php
rename to phpunit/tests/fonts-api/wpFontsUtils/convertFontFamilyIntoHandle.php
index 288a0d11715e2f..19b2f15c826ed1 100644
--- a/phpunit/fonts-api/wpFontsUtils/convertFontFamilyIntoHandle-test.php
+++ b/phpunit/tests/fonts-api/wpFontsUtils/convertFontFamilyIntoHandle.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group fontsapi
diff --git a/phpunit/fonts-api/wpFontsUtils/convertVariationIntoHandle-test.php b/phpunit/tests/fonts-api/wpFontsUtils/convertVariationIntoHandle.php
similarity index 98%
rename from phpunit/fonts-api/wpFontsUtils/convertVariationIntoHandle-test.php
rename to phpunit/tests/fonts-api/wpFontsUtils/convertVariationIntoHandle.php
index 6be7f585c5a356..9268aac8ce372b 100644
--- a/phpunit/fonts-api/wpFontsUtils/convertVariationIntoHandle-test.php
+++ b/phpunit/tests/fonts-api/wpFontsUtils/convertVariationIntoHandle.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group fontsapi
diff --git a/phpunit/fonts-api/wpFontsUtils/getFontFamilyFromVariation-test.php b/phpunit/tests/fonts-api/wpFontsUtils/getFontFamilyFromVariation.php
similarity index 98%
rename from phpunit/fonts-api/wpFontsUtils/getFontFamilyFromVariation-test.php
rename to phpunit/tests/fonts-api/wpFontsUtils/getFontFamilyFromVariation.php
index 21f1c4d5c6a594..2b3e3689c4317f 100644
--- a/phpunit/fonts-api/wpFontsUtils/getFontFamilyFromVariation-test.php
+++ b/phpunit/tests/fonts-api/wpFontsUtils/getFontFamilyFromVariation.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group fontsapi
diff --git a/phpunit/fonts-api/wpFontsUtils/isDefined-test.php b/phpunit/tests/fonts-api/wpFontsUtils/isDefined.php
similarity index 96%
rename from phpunit/fonts-api/wpFontsUtils/isDefined-test.php
rename to phpunit/tests/fonts-api/wpFontsUtils/isDefined.php
index e770559b33a0e0..3ae48ad52671a2 100644
--- a/phpunit/fonts-api/wpFontsUtils/isDefined-test.php
+++ b/phpunit/tests/fonts-api/wpFontsUtils/isDefined.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/../wp-fonts-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * @group fontsapi
diff --git a/phpunit/fonts-api/wpPrintFonts-test.php b/phpunit/tests/fonts-api/wpPrintFonts.php
similarity index 98%
rename from phpunit/fonts-api/wpPrintFonts-test.php
rename to phpunit/tests/fonts-api/wpPrintFonts.php
index 4f50cf6a8cd5ea..40b416aa56421f 100644
--- a/phpunit/fonts-api/wpPrintFonts-test.php
+++ b/phpunit/tests/fonts-api/wpPrintFonts.php
@@ -6,8 +6,8 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/wp-fonts-testcase.php';
-require_once __DIR__ . '/../fixtures/mock-provider.php';
+require_once __DIR__ . '/base.php';
+require_once GUTENBERG_DIR_TESTFIXTURES . '/mock-provider.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpRegisterFontProvider-test.php b/phpunit/tests/fonts-api/wpRegisterFontProvider.php
similarity index 95%
rename from phpunit/fonts-api/wpRegisterFontProvider-test.php
rename to phpunit/tests/fonts-api/wpRegisterFontProvider.php
index 157ab7f4d0a66c..9288ee3850672d 100644
--- a/phpunit/fonts-api/wpRegisterFontProvider-test.php
+++ b/phpunit/tests/fonts-api/wpRegisterFontProvider.php
@@ -6,8 +6,8 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/wp-fonts-testcase.php';
-require_once __DIR__ . '/../fixtures/mock-provider.php';
+require_once __DIR__ . '/base.php';
+require_once GUTENBERG_DIR_TESTFIXTURES . '/mock-provider.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts-api/wpRegisterFonts-test.php b/phpunit/tests/fonts-api/wpRegisterFonts.php
similarity index 98%
rename from phpunit/fonts-api/wpRegisterFonts-test.php
rename to phpunit/tests/fonts-api/wpRegisterFonts.php
index da54fd6438f970..c57c1406a6cacc 100644
--- a/phpunit/fonts-api/wpRegisterFonts-test.php
+++ b/phpunit/tests/fonts-api/wpRegisterFonts.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts API
  */
 
-require_once __DIR__ . '/wp-fonts-testcase.php';
+require_once __DIR__ . '/base.php';
 
 /**
  * @group  fontsapi
diff --git a/phpunit/fonts/font-face/wp-font-face-testcase.php b/phpunit/tests/fonts/font-face/base.php
similarity index 98%
rename from phpunit/fonts/font-face/wp-font-face-testcase.php
rename to phpunit/tests/fonts/font-face/base.php
index f36b00833e69c8..4d8d487cb47c97 100644
--- a/phpunit/fonts/font-face/wp-font-face-testcase.php
+++ b/phpunit/tests/fonts/font-face/base.php
@@ -62,7 +62,7 @@ public static function set_up_before_class() {
 		parent::set_up_before_class();
 
 		if ( self::$requires_switch_theme_fixtures ) {
-			self::$theme_root = realpath( __DIR__ . '/../../data/themedir1' );
+			self::$theme_root = realpath( GUTENBERG_DIR_TESTDATA . '/themedir1' );
 		}
 	}
 
diff --git a/phpunit/fonts/font-face/wp-font-face-tests-dataset.php b/phpunit/tests/fonts/font-face/wp-font-face-tests-dataset.php
similarity index 100%
rename from phpunit/fonts/font-face/wp-font-face-tests-dataset.php
rename to phpunit/tests/fonts/font-face/wp-font-face-tests-dataset.php
diff --git a/phpunit/fonts/font-face/wpFontFace/generateAndPrint-test.php b/phpunit/tests/fonts/font-face/wpFontFace/generateAndPrint.php
similarity index 94%
rename from phpunit/fonts/font-face/wpFontFace/generateAndPrint-test.php
rename to phpunit/tests/fonts/font-face/wpFontFace/generateAndPrint.php
index 2b31b387694817..ac68c006ff4d4c 100644
--- a/phpunit/fonts/font-face/wpFontFace/generateAndPrint-test.php
+++ b/phpunit/tests/fonts/font-face/wpFontFace/generateAndPrint.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts
  */
 
-require_once __DIR__ . '/../wp-font-face-tests-dataset.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * Test WP_Font_Face::generate_and_print().
diff --git a/phpunit/fonts/font-face/wpFontFaceResolver/getFontsFromThemeJson-test.php b/phpunit/tests/fonts/font-face/wpFontFaceResolver/getFontsFromThemeJson.php
similarity index 98%
rename from phpunit/fonts/font-face/wpFontFaceResolver/getFontsFromThemeJson-test.php
rename to phpunit/tests/fonts/font-face/wpFontFaceResolver/getFontsFromThemeJson.php
index 3a5626ef6eaa12..51342b19cafb12 100644
--- a/phpunit/fonts/font-face/wpFontFaceResolver/getFontsFromThemeJson-test.php
+++ b/phpunit/tests/fonts/font-face/wpFontFaceResolver/getFontsFromThemeJson.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts
  */
 
-require_once __DIR__ . '/../wp-font-face-testcase.php';
+require_once dirname( __DIR__ ) . '/base.php';
 
 /**
  * Tests WP_Font_Face_Resolver::get_fonts_from_theme_json().
diff --git a/phpunit/fonts/font-face/wpPrintFontFaces-test.php b/phpunit/tests/fonts/font-face/wpPrintFontFaces.php
similarity index 96%
rename from phpunit/fonts/font-face/wpPrintFontFaces-test.php
rename to phpunit/tests/fonts/font-face/wpPrintFontFaces.php
index c6d4203fd50532..cb3ff2471cc64f 100644
--- a/phpunit/fonts/font-face/wpPrintFontFaces-test.php
+++ b/phpunit/tests/fonts/font-face/wpPrintFontFaces.php
@@ -6,7 +6,7 @@
  * @subpackage Fonts
  */
 
-require_once __DIR__ . '/wp-font-face-testcase.php';
+require_once __DIR__ . '/base.php';
 
 /**
  * Test wp_print_font_faces().
diff --git a/phpunit/fonts/font-library/class-wp-rest-font-library-controller-test.php b/phpunit/tests/fonts/font-library/class-wp-rest-font-library-controller.php
similarity index 100%
rename from phpunit/fonts/font-library/class-wp-rest-font-library-controller-test.php
rename to phpunit/tests/fonts/font-library/class-wp-rest-font-library-controller.php
diff --git a/phpunit/fonts/font-library/wpFontFamily/__construct-test.php b/phpunit/tests/fonts/font-library/wpFontFamily/__construct.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontFamily/__construct-test.php
rename to phpunit/tests/fonts/font-library/wpFontFamily/__construct.php
diff --git a/phpunit/fonts/font-library/wpFontFamily/base.php b/phpunit/tests/fonts/font-library/wpFontFamily/base.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontFamily/base.php
rename to phpunit/tests/fonts/font-library/wpFontFamily/base.php
diff --git a/phpunit/fonts/font-library/wpFontFamily/getData-test.php b/phpunit/tests/fonts/font-library/wpFontFamily/getData.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontFamily/getData-test.php
rename to phpunit/tests/fonts/font-library/wpFontFamily/getData.php
diff --git a/phpunit/fonts/font-library/wpFontFamily/getDataAsJson-test.php b/phpunit/tests/fonts/font-library/wpFontFamily/getDataAsJson.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontFamily/getDataAsJson-test.php
rename to phpunit/tests/fonts/font-library/wpFontFamily/getDataAsJson.php
diff --git a/phpunit/fonts/font-library/wpFontFamily/getFontPost-test.php b/phpunit/tests/fonts/font-library/wpFontFamily/getFontPost.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontFamily/getFontPost-test.php
rename to phpunit/tests/fonts/font-library/wpFontFamily/getFontPost.php
diff --git a/phpunit/fonts/font-library/wpFontFamily/hasFontFaces-test.php b/phpunit/tests/fonts/font-library/wpFontFamily/hasFontFaces.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontFamily/hasFontFaces-test.php
rename to phpunit/tests/fonts/font-library/wpFontFamily/hasFontFaces.php
diff --git a/phpunit/fonts/font-library/wpFontFamily/install-test.php b/phpunit/tests/fonts/font-library/wpFontFamily/install.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontFamily/install-test.php
rename to phpunit/tests/fonts/font-library/wpFontFamily/install.php
diff --git a/phpunit/fonts/font-library/wpFontFamily/uninstall-test.php b/phpunit/tests/fonts/font-library/wpFontFamily/uninstall.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontFamily/uninstall-test.php
rename to phpunit/tests/fonts/font-library/wpFontFamily/uninstall.php
diff --git a/phpunit/fonts/font-library/wpFontFamilyUtils/getFilenameFromFontFace-test.php b/phpunit/tests/fonts/font-library/wpFontFamilyUtils/getFilenameFromFontFace.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontFamilyUtils/getFilenameFromFontFace-test.php
rename to phpunit/tests/fonts/font-library/wpFontFamilyUtils/getFilenameFromFontFace.php
diff --git a/phpunit/fonts/font-library/wpFontFamilyUtils/hasFontMimeType-test.php b/phpunit/tests/fonts/font-library/wpFontFamilyUtils/hasFontMimeType.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontFamilyUtils/hasFontMimeType-test.php
rename to phpunit/tests/fonts/font-library/wpFontFamilyUtils/hasFontMimeType.php
diff --git a/phpunit/fonts/font-library/wpFontFamilyUtils/mergeFontsData-test.php b/phpunit/tests/fonts/font-library/wpFontFamilyUtils/mergeFontsData.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontFamilyUtils/mergeFontsData-test.php
rename to phpunit/tests/fonts/font-library/wpFontFamilyUtils/mergeFontsData.php
diff --git a/phpunit/fonts/font-library/wpFontLibrary/getFontsDir-test.php b/phpunit/tests/fonts/font-library/wpFontLibrary/getFontsDir.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontLibrary/getFontsDir-test.php
rename to phpunit/tests/fonts/font-library/wpFontLibrary/getFontsDir.php
diff --git a/phpunit/fonts/font-library/wpFontLibrary/setUploadDir-test.php b/phpunit/tests/fonts/font-library/wpFontLibrary/setUploadDir.php
similarity index 100%
rename from phpunit/fonts/font-library/wpFontLibrary/setUploadDir-test.php
rename to phpunit/tests/fonts/font-library/wpFontLibrary/setUploadDir.php