diff --git a/tests/phpunit/data/languages/themes/fse-pl_PL.mo b/tests/phpunit/data/languages/themes/fse-pl_PL.mo
new file mode 100644
index 0000000000..0ff620e64a
Binary files /dev/null and b/tests/phpunit/data/languages/themes/fse-pl_PL.mo differ
diff --git a/tests/phpunit/tests/blocks/data/languages/themes/fse-pl_PL.po b/tests/phpunit/data/languages/themes/fse-pl_PL.po
similarity index 100%
rename from tests/phpunit/tests/blocks/data/languages/themes/fse-pl_PL.po
rename to tests/phpunit/data/languages/themes/fse-pl_PL.po
diff --git a/tests/phpunit/data/themedir1/fse/index.php b/tests/phpunit/data/themedir1/fse/index.php
new file mode 100644
index 0000000000..c674182076
--- /dev/null
+++ b/tests/phpunit/data/themedir1/fse/index.php
@@ -0,0 +1,4 @@
+<?php
+/**
+ * Dummy theme.
+ */
diff --git a/tests/phpunit/tests/blocks/data/themedir1/fse/style.css b/tests/phpunit/data/themedir1/fse/style.css
similarity index 100%
rename from tests/phpunit/tests/blocks/data/themedir1/fse/style.css
rename to tests/phpunit/data/themedir1/fse/style.css
diff --git a/tests/phpunit/tests/blocks/data/themedir1/fse/theme.json b/tests/phpunit/data/themedir1/fse/theme.json
similarity index 100%
rename from tests/phpunit/tests/blocks/data/themedir1/fse/theme.json
rename to tests/phpunit/data/themedir1/fse/theme.json
diff --git a/tests/phpunit/tests/blocks/class-wp-theme-json-resolver-test.php b/tests/phpunit/tests/theme/class-wp-theme-json-resolver.php
similarity index 93%
rename from tests/phpunit/tests/blocks/class-wp-theme-json-resolver-test.php
rename to tests/phpunit/tests/theme/class-wp-theme-json-resolver.php
index 22a657fa08..3be478c8a2 100644
--- a/tests/phpunit/tests/blocks/class-wp-theme-json-resolver-test.php
+++ b/tests/phpunit/tests/theme/class-wp-theme-json-resolver.php
@@ -3,14 +3,15 @@
 /**
  * Test WP_Theme_JSON_Resolver class.
  *
- * @package Gutenberg
+ * @package WordPress
+ * @since 5.8.0
  */
 
 class WP_Theme_JSON_Resolver_Test extends WP_UnitTestCase {
 
 	function setUp() {
 		parent::setUp();
-		$this->theme_root = realpath( __DIR__ . '/data/themedir1' );
+		$this->theme_root = realpath( DIR_TESTDATA . '/themedir1' );
 
 		$this->orig_theme_dir = $GLOBALS['wp_theme_directories'];
 
@@ -40,6 +41,9 @@ class WP_Theme_JSON_Resolver_Test extends WP_UnitTestCase {
 		return 'pl_PL';
 	}
 
+	/**
+	 * @ticket 52991
+	 */
 	function test_fields_are_extracted() {
 		$actual = WP_Theme_JSON_Resolver::get_fields_to_translate();
 
@@ -84,9 +88,12 @@ class WP_Theme_JSON_Resolver_Test extends WP_UnitTestCase {
 		$this->assertEquals( $expected, $actual );
 	}
 
+	/**
+	 * @ticket 52991
+	 */
 	function test_translations_are_applied() {
 		add_filter( 'locale', array( $this, 'filter_set_locale_to_polish' ) );
-		load_textdomain( 'fse', realpath( __DIR__ . '/data/languages/themes/fse-pl_PL.mo' ) );
+		load_textdomain( 'fse', realpath( DIR_TESTDATA . '/languages/themes/fse-pl_PL.mo' ) );
 
 		switch_theme( 'fse' );
 
@@ -131,6 +138,9 @@ class WP_Theme_JSON_Resolver_Test extends WP_UnitTestCase {
 		);
 	}
 
+	/**
+	 * @ticket 52991
+	 */
 	function test_switching_themes_recalculates_data() {
 		// By default, the theme for unit tests is "default",
 		// which doesn't have theme.json support.
diff --git a/tests/phpunit/tests/blocks/class-wp-theme-json-test.php b/tests/phpunit/tests/theme/class-wp-theme-json.php
similarity index 97%
rename from tests/phpunit/tests/blocks/class-wp-theme-json-test.php
rename to tests/phpunit/tests/theme/class-wp-theme-json.php
index 0f338e061a..b981bd798e 100644
--- a/tests/phpunit/tests/blocks/class-wp-theme-json-test.php
+++ b/tests/phpunit/tests/theme/class-wp-theme-json.php
@@ -3,11 +3,15 @@
 /**
  * Test WP_Theme_JSON class.
  *
- * @package Gutenberg
+ * @package WordPress
+ * @since 5.8.0
  */
 
 class WP_Theme_JSON_Test extends WP_UnitTestCase {
 
+	/**
+	 * @ticket 52991
+	 */
 	function test_get_settings() {
 		$theme_json = new WP_Theme_JSON(
 			array(
@@ -52,6 +56,9 @@ class WP_Theme_JSON_Test extends WP_UnitTestCase {
 		$this->assertEqualSetsWithIndex( $expected, $actual );
 	}
 
+	/**
+	 * @ticket 52991
+	 */
 	public function test_merge_incoming_data() {
 		$initial = array(
 			'version'  => WP_Theme_JSON::LATEST_SCHEMA,
@@ -259,6 +266,9 @@ class WP_Theme_JSON_Test extends WP_UnitTestCase {
 		$this->assertEqualSetsWithIndex( $expected, $actual );
 	}
 
+	/**
+	 * @ticket 52991
+	 */
 	function test_get_from_editor_settings() {
 		$input = array(
 			'disableCustomColors'    => true,
@@ -332,6 +342,9 @@ class WP_Theme_JSON_Test extends WP_UnitTestCase {
 		$this->assertEqualSetsWithIndex( $expected, $actual );
 	}
 
+	/**
+	 * @ticket 52991
+	 */
 	function test_get_editor_settings_no_theme_support() {
 		$input = array(
 			'__unstableEnableFullSiteEditingBlocks' => false,
@@ -384,6 +397,9 @@ class WP_Theme_JSON_Test extends WP_UnitTestCase {
 		$this->assertEqualSetsWithIndex( $expected, $actual );
 	}
 
+	/**
+	 * @ticket 52991
+	 */
 	function test_get_editor_settings_blank() {
 		$expected = array(
 			'version'  => WP_Theme_JSON::LATEST_SCHEMA,
@@ -394,6 +410,9 @@ class WP_Theme_JSON_Test extends WP_UnitTestCase {
 		$this->assertEqualSetsWithIndex( $expected, $actual );
 	}
 
+	/**
+	 * @ticket 52991
+	 */
 	function test_get_editor_settings_custom_units_can_be_disabled() {
 		add_theme_support( 'custom-units', array() );
 		$input = get_default_block_editor_settings();
@@ -408,6 +427,9 @@ class WP_Theme_JSON_Test extends WP_UnitTestCase {
 		$this->assertEqualSetsWithIndex( $expected, $actual['settings']['spacing'] );
 	}
 
+	/**
+	 * @ticket 52991
+	 */
 	function test_get_editor_settings_custom_units_can_be_enabled() {
 		add_theme_support( 'custom-units' );
 		$input = get_default_block_editor_settings();
@@ -422,6 +444,9 @@ class WP_Theme_JSON_Test extends WP_UnitTestCase {
 		$this->assertEqualSetsWithIndex( $expected, $actual['settings']['spacing'] );
 	}
 
+	/**
+	 * @ticket 52991
+	 */
 	function test_get_editor_settings_custom_units_can_be_filtered() {
 		add_theme_support( 'custom-units', 'rem', 'em' );
 		$input = get_default_block_editor_settings();
diff --git a/tests/phpunit/tests/theme/themeDir.php b/tests/phpunit/tests/theme/themeDir.php
index b2a2542895..b7dc139521 100644
--- a/tests/phpunit/tests/theme/themeDir.php
+++ b/tests/phpunit/tests/theme/themeDir.php
@@ -161,6 +161,7 @@ class Tests_Theme_ThemeDir extends WP_UnitTestCase {
 			'Internationalized Theme',
 			'camelCase',
 			'REST Theme',
+			'FSE Theme',
 		);
 
 		sort( $theme_names );