diff --git a/lib/experimental/fonts/font-library/class-wp-font-collection.php b/lib/experimental/fonts/font-library/class-wp-font-collection.php
index 6189da5fa984b1..1ff96b1343b453 100644
--- a/lib/experimental/fonts/font-library/class-wp-font-collection.php
+++ b/lib/experimental/fonts/font-library/class-wp-font-collection.php
@@ -21,41 +21,128 @@
 class WP_Font_Collection {
 
 	/**
-	 * Font collection configuration.
+	 * The unique slug for the font collection.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @var string
+	 */
+	private $slug;
+
+	/**
+	 * The name of the font collection.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @var string
+	 */
+	private $name;
+
+	/**
+	 * Description of the font collection.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @var string
+	 */
+	private $description;
+
+	/**
+	 * Source of the font collection.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @var string
+	 */
+	private $src;
+
+	/**
+	 * Array of font families in the collection.
 	 *
 	 * @since 6.5.0
 	 *
 	 * @var array
 	 */
-	private $config;
+	private $font_families;
+
+	/**
+	 * Categories associated with the font collection.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @var array
+	 */
+	private $categories;
+
 
 	/**
 	 * WP_Font_Collection constructor.
 	 *
 	 * @since 6.5.0
 	 *
-	 * @param array $config Font collection config options.
-	 *  See {@see wp_register_font_collection()} for the supported fields.
-	 * @throws Exception If the required parameters are missing.
+	 * @param array $config Font collection config options. {
+	 *      @type string $slug        The font collection's unique slug.
+	 *      @type string $name        The font collection's name.
+	 *      @type string $description The font collection's description.
+	 *      @type string $src         The font collection's source.
+	 *      @type array  $font_families An array of font families in the font collection.
+	 *      @type array  $categories The font collection's categories.
+	 *  }
 	 */
 	public function __construct( $config ) {
-		if ( empty( $config ) || ! is_array( $config ) ) {
-			throw new Exception( 'Font Collection config options is required as a non-empty array.' );
-		}
+		$this->is_config_valid( $config );
+
+		$this->slug          = isset( $config['slug'] ) ? $config['slug'] : '';
+		$this->name          = isset( $config['name'] ) ? $config['name'] : '';
+		$this->description   = isset( $config['description'] ) ? $config['description'] : '';
+		$this->src           = isset( $config['src'] ) ? $config['src'] : '';
+		$this->font_families = isset( $config['font_families'] ) ? $config['font_families'] : array();
+		$this->categories    = isset( $config['categories'] ) ? $config['categories'] : array();
+	}
 
-		if ( empty( $config['slug'] ) || ! is_string( $config['slug'] ) ) {
-			throw new Exception( 'Font Collection config slug is required as a non-empty string.' );
+	/**
+	 * Checks if the font collection config is valid.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @param array $config Font collection config options. {
+	 *      @type string $slug        The font collection's unique slug.
+	 *      @type string $name        The font collection's name.
+	 *      @type string $description The font collection's description.
+	 *      @type string $src         The font collection's source.
+	 *      @type array  $font_families An array of font families in the font collection.
+	 *      @type array  $categories The font collection's categories.
+	 *  }
+	 * @return bool True if the font collection config is valid and false otherwise.
+	 */
+	public static function is_config_valid( $config ) {
+		if ( empty( $config ) || ! is_array( $config ) ) {
+			_doing_it_wrong( __METHOD__, __( 'Font Collection config options are required as a non-empty array.', 'gutenberg' ), '6.5.0' );
+			return false;
 		}
 
-		if ( empty( $config['name'] ) || ! is_string( $config['name'] ) ) {
-			throw new Exception( 'Font Collection config name is required as a non-empty string.' );
+		$required_keys = array( 'slug', 'name' );
+		foreach ( $required_keys as $key ) {
+			if ( empty( $config[ $key ] ) ) {
+				_doing_it_wrong(
+					__METHOD__,
+					// translators: %s: Font collection config key.
+					sprintf( __( 'Font Collection config %s is required as a non-empty string.', 'gutenberg' ), $key ),
+					'6.5.0'
+				);
+				return false;
+			}
 		}
 
-		if ( ( empty( $config['src'] ) || ! is_string( $config['src'] ) ) && ( empty( $config['data'] ) ) ) {
-			throw new Exception( 'Font Collection config "src" option OR "data" option is required.' );
+		if (
+			( empty( $config['src'] ) && empty( $config['font_families'] ) ) ||
+			( ! empty( $config['src'] ) && ! empty( $config['font_families'] ) )
+		) {
+			_doing_it_wrong( __METHOD__, __( 'Font Collection config "src" option OR "font_families" option are required.', 'gutenberg' ), '6.5.0' );
+			return false;
 		}
 
-		$this->config = $config;
+		return true;
 	}
 
 	/**
@@ -73,56 +160,59 @@ public function __construct( $config ) {
 	 */
 	public function get_config() {
 		return array(
-			'slug'        => $this->config['slug'],
-			'name'        => $this->config['name'],
-			'description' => $this->config['description'] ?? '',
+			'slug'        => $this->slug,
+			'name'        => $this->name,
+			'description' => $this->description,
 		);
 	}
 
 	/**
-	 * Gets the font collection config and data.
+	 * Gets the font collection content.
 	 *
-	 * This function returns an array containing the font collection's unique ID,
-	 * name, and its data as a PHP array.
+	 * Load the font collection data from the src if it is not already loaded.
 	 *
 	 * @since 6.5.0
 	 *
-	 * @return array {
-	 *     An array of font collection config and data.
+	 * @return array|WP_Error {
+	 *     An array of font collection contents.
 	 *
-	 *     @type string $slug          The font collection's unique ID.
-	 *     @type string $name        The font collection's name.
-	 *     @type string $description The font collection's description.
-	 *     @type array  $data        The font collection's data as a PHP array.
+	 *     @type array $font_families      The font collection's font families.
+	 *     @type string $categories        The font collection's categories.
 	 * }
+	 *
+	 * A WP_Error object if there was an error loading the font collection data.
 	 */
-	public function get_config_and_data() {
-		$config_and_data         = $this->get_config();
-		$config_and_data['data'] = $this->load_data();
-		return $config_and_data;
+	public function get_content() {
+		// If the font families are not loaded, and the src is not empty, load the data from the src.
+		if ( empty( $this->font_families ) && ! empty( $this->src ) ) {
+			$data = $this->load_contents_from_src();
+			if ( is_wp_error( $data ) ) {
+				return $data;
+			}
+		}
+
+		return array(
+			'font_families' => $this->font_families,
+			'categories'    => $this->categories,
+		);
 	}
 
 	/**
-	 * Loads the font collection data.
+	 * Loads the font collection data from the src.
 	 *
 	 * @since 6.5.0
 	 *
 	 * @return array|WP_Error An array containing the list of font families in font-collection.json format on success,
 	 *                        else an instance of WP_Error on failure.
 	 */
-	public function load_data() {
-
-		if ( ! empty( $this->config['data'] ) ) {
-			return $this->config['data'];
-		}
-
+	private function load_contents_from_src() {
 		// If the src is a URL, fetch the data from the URL.
-		if ( str_contains( $this->config['src'], 'http' ) && str_contains( $this->config['src'], '://' ) ) {
-			if ( ! wp_http_validate_url( $this->config['src'] ) ) {
+		if ( preg_match( '#^https?://#', $this->src ) ) {
+			if ( ! wp_http_validate_url( $this->src ) ) {
 				return new WP_Error( 'font_collection_read_error', __( 'Invalid URL for Font Collection data.', 'gutenberg' ) );
 			}
 
-			$response = wp_remote_get( $this->config['src'] );
+			$response = wp_remote_get( $this->src );
 			if ( is_wp_error( $response ) || 200 !== wp_remote_retrieve_response_code( $response ) ) {
 				return new WP_Error( 'font_collection_read_error', __( 'Error fetching the Font Collection data from a URL.', 'gutenberg' ) );
 			}
@@ -133,15 +223,22 @@ public function load_data() {
 			}
 			// If the src is a file path, read the data from the file.
 		} else {
-			if ( ! file_exists( $this->config['src'] ) ) {
+			if ( ! file_exists( $this->src ) ) {
 				return new WP_Error( 'font_collection_read_error', __( 'Font Collection data JSON file does not exist.', 'gutenberg' ) );
 			}
-			$data = wp_json_file_decode( $this->config['src'], array( 'associative' => true ) );
+			$data = wp_json_file_decode( $this->src, array( 'associative' => true ) );
 			if ( empty( $data ) ) {
 				return new WP_Error( 'font_collection_read_error', __( 'Error reading the Font Collection data JSON file contents.', 'gutenberg' ) );
 			}
 		}
 
+		if ( empty( $data['font_families'] ) ) {
+			return new WP_Error( 'font_collection_contents_error', __( 'Font Collection data JSON file does not contain font families.', 'gutenberg' ) );
+		}
+
+		$this->font_families = $data['font_families'];
+		$this->categories    = $data['categories'] ?? array();
+
 		return $data;
 	}
 }
diff --git a/lib/experimental/fonts/font-library/class-wp-font-library.php b/lib/experimental/fonts/font-library/class-wp-font-library.php
index fd36f6ba073c4f..51a84b957ea117 100644
--- a/lib/experimental/fonts/font-library/class-wp-font-library.php
+++ b/lib/experimental/fonts/font-library/class-wp-font-library.php
@@ -62,11 +62,17 @@ public static function get_expected_font_mime_types_per_php_version( $php_versio
 	 * @return WP_Font_Collection|WP_Error A font collection is it was registered successfully and a WP_Error otherwise.
 	 */
 	public static function register_font_collection( $config ) {
+		if ( ! WP_Font_Collection::is_config_valid( $config ) ) {
+			$error_message = __( 'Font collection config is invalid.', 'gutenberg' );
+			return new WP_Error( 'font_collection_registration_error', $error_message );
+		}
+
 		$new_collection = new WP_Font_Collection( $config );
-		if ( self::is_collection_registered( $config['slug'] ) ) {
+
+		if ( self::is_collection_registered( $new_collection->get_config()['slug'] ) ) {
 			$error_message = sprintf(
 				/* translators: %s: Font collection slug. */
-				__( 'Font collection with slug: "%s" is already registered.', 'default' ),
+				__( 'Font collection with slug: "%s" is already registered.', 'gutenberg' ),
 				$config['slug']
 			);
 			_doing_it_wrong(
@@ -76,7 +82,7 @@ public static function register_font_collection( $config ) {
 			);
 			return new WP_Error( 'font_collection_registration_error', $error_message );
 		}
-		self::$collections[ $config['slug'] ] = $new_collection;
+		self::$collections[ $new_collection->get_config()['slug'] ] = $new_collection;
 		return $new_collection;
 	}
 
diff --git a/lib/experimental/fonts/font-library/class-wp-rest-font-collections-controller.php b/lib/experimental/fonts/font-library/class-wp-rest-font-collections-controller.php
index c7595a56413b9b..51fd14fffaa953 100644
--- a/lib/experimental/fonts/font-library/class-wp-rest-font-collections-controller.php
+++ b/lib/experimental/fonts/font-library/class-wp-rest-font-collections-controller.php
@@ -42,8 +42,8 @@ public function register_routes() {
 			array(
 				array(
 					'methods'             => WP_REST_Server::READABLE,
-					'callback'            => array( $this, 'get_font_collections' ),
-					'permission_callback' => array( $this, 'update_font_library_permissions_check' ),
+					'callback'            => array( $this, 'get_items' ),
+					'permission_callback' => array( $this, 'get_items_permissions_check' ),
 				),
 			)
 		);
@@ -54,13 +54,29 @@ public function register_routes() {
 			array(
 				array(
 					'methods'             => WP_REST_Server::READABLE,
-					'callback'            => array( $this, 'get_font_collection' ),
-					'permission_callback' => array( $this, 'update_font_library_permissions_check' ),
+					'callback'            => array( $this, 'get_item' ),
+					'permission_callback' => array( $this, 'get_items_permissions_check' ),
 				),
 			)
 		);
 	}
 
+	/**
+	 * Gets the font collections available.
+	 *
+	 * @since 6.5.0
+	 *
+	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+	 */
+	public function get_items( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+		$collections = array();
+		foreach ( WP_Font_Library::get_font_collections() as $collection ) {
+			$collections[] = $collection->get_config();
+		}
+
+		return rest_ensure_response( $collections, 200 );
+	}
+
 	/**
 	 * Gets a font collection.
 	 *
@@ -69,54 +85,42 @@ public function register_routes() {
 	 * @param WP_REST_Request $request Full details about the request.
 	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
 	 */
-	public function get_font_collection( $request ) {
+	public function get_item( $request ) {
 		$slug       = $request->get_param( 'slug' );
 		$collection = WP_Font_Library::get_font_collection( $slug );
+
 		// If the collection doesn't exist returns a 404.
 		if ( is_wp_error( $collection ) ) {
 			$collection->add_data( array( 'status' => 404 ) );
 			return $collection;
 		}
-		$config_and_data = $collection->get_config_and_data();
-		$collection_data = $config_and_data['data'];
 
-		// If there was an error getting the collection data, return the error.
-		if ( is_wp_error( $collection_data ) ) {
-			$collection_data->add_data( array( 'status' => 500 ) );
-			return $collection_data;
-		}
-
-		return new WP_REST_Response( $config_and_data );
-	}
+		$config   = $collection->get_config();
+		$contents = $collection->get_content();
 
-	/**
-	 * Gets the font collections available.
-	 *
-	 * @since 6.5.0
-	 *
-	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
-	 */
-	public function get_font_collections() {
-		$collections = array();
-		foreach ( WP_Font_Library::get_font_collections() as $collection ) {
-			$collections[] = $collection->get_config_and_data();
+		// If there was an error getting the collection data, return the error.
+		if ( is_wp_error( $contents ) ) {
+			$contents->add_data( array( 'status' => 500 ) );
+			return $contents;
 		}
 
-		return new WP_REST_Response( $collections, 200 );
+		$collection_data = array_merge( $config, $contents );
+		return rest_ensure_response( $collection_data );
 	}
 
 	/**
-	 * Checks whether the user has permissions to update the Font Library.
+	 * Checks whether the user has permissions to use the Fonts Collections.
 	 *
 	 * @since 6.5.0
 	 *
 	 * @return true|WP_Error True if the request has write access for the item, WP_Error object otherwise.
 	 */
-	public function update_font_library_permissions_check() {
+	public function get_items_permissions_check( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+
 		if ( ! current_user_can( 'edit_theme_options' ) ) {
 			return new WP_Error(
-				'rest_cannot_update_font_library',
-				__( 'Sorry, you are not allowed to update the Font Library on this site.', 'gutenberg' ),
+				'rest_cannot_read',
+				__( 'Sorry, you are not allowed to use the Font Library on this site.', 'gutenberg' ),
 				array(
 					'status' => rest_authorization_required_code(),
 				)
diff --git a/lib/experimental/fonts/font-library/font-library.php b/lib/experimental/fonts/font-library/font-library.php
index eb76cbab191280..f16c118317eaec 100644
--- a/lib/experimental/fonts/font-library/font-library.php
+++ b/lib/experimental/fonts/font-library/font-library.php
@@ -134,7 +134,8 @@ function wp_unregister_font_collection( $collection_id ) {
 	'slug'        => 'default-font-collection',
 	'name'        => 'Google Fonts',
 	'description' => __( 'Add from Google Fonts. Fonts are copied to and served from your site.', 'gutenberg' ),
-	'src'         => 'https://s.w.org/images/fonts/16.7/collections/google-fonts-with-preview.json',
+	// TODO: This URL needs to be updated to the wporg hosted one prior to the Gutenberg 17.6 release.
+	'src'         => 'https://raw.githubusercontent.com/WordPress/google-fonts-to-wordpress-collection/main/releases/gutenberg-17.6/google-fonts.json',
 );
 
 wp_register_font_collection( $default_font_collection );
diff --git a/packages/edit-site/src/components/global-styles/font-library-modal/context.js b/packages/edit-site/src/components/global-styles/font-library-modal/context.js
index 078d11e235c043..c9e51c514104e7 100644
--- a/packages/edit-site/src/components/global-styles/font-library-modal/context.js
+++ b/packages/edit-site/src/components/global-styles/font-library-modal/context.js
@@ -394,16 +394,16 @@ function FontLibraryProvider( { children } ) {
 		const response = await fetchFontCollections();
 		setFontCollections( response );
 	};
-	const getFontCollection = async ( id ) => {
+	const getFontCollection = async ( slug ) => {
 		try {
 			const hasData = !! collections.find(
-				( collection ) => collection.id === id
-			)?.data;
+				( collection ) => collection.slug === slug
+			)?.font_families;
 			if ( hasData ) return;
-			const response = await fetchFontCollection( id );
+			const response = await fetchFontCollection( slug );
 			const updatedCollections = collections.map( ( collection ) =>
-				collection.id === id
-					? { ...collection, data: { ...response?.data } }
+				collection.slug === slug
+					? { ...collection, ...response }
 					: collection
 			);
 			setFontCollections( updatedCollections );
diff --git a/packages/edit-site/src/components/global-styles/font-library-modal/font-collection.js b/packages/edit-site/src/components/global-styles/font-library-modal/font-collection.js
index 5b6eeb2481e7a4..793ca9c753f337 100644
--- a/packages/edit-site/src/components/global-styles/font-library-modal/font-collection.js
+++ b/packages/edit-site/src/components/global-styles/font-library-modal/font-collection.js
@@ -36,8 +36,8 @@ const DEFAULT_CATEGORY = {
 	id: 'all',
 	name: __( 'All' ),
 };
-function FontCollection( { id } ) {
-	const requiresPermission = id === 'default-font-collection';
+function FontCollection( { slug } ) {
+	const requiresPermission = slug === 'default-font-collection';
 
 	const getGoogleFontsPermissionFromStorage = () => {
 		return (
@@ -57,7 +57,7 @@ function FontCollection( { id } ) {
 	const { collections, getFontCollection, installFont } =
 		useContext( FontLibraryContext );
 	const selectedCollection = collections.find(
-		( collection ) => collection.id === id
+		( collection ) => collection.slug === slug
 	);
 
 	useEffect( () => {
@@ -69,12 +69,12 @@ function FontCollection( { id } ) {
 		handleStorage();
 		window.addEventListener( 'storage', handleStorage );
 		return () => window.removeEventListener( 'storage', handleStorage );
-	}, [ id, requiresPermission ] );
+	}, [ slug, requiresPermission ] );
 
 	useEffect( () => {
 		const fetchFontCollection = async () => {
 			try {
-				await getFontCollection( id );
+				await getFontCollection( slug );
 				resetFilters();
 			} catch ( e ) {
 				setNotice( {
@@ -85,12 +85,12 @@ function FontCollection( { id } ) {
 			}
 		};
 		fetchFontCollection();
-	}, [ id, getFontCollection ] );
+	}, [ slug, getFontCollection ] );
 
 	useEffect( () => {
 		setSelectedFont( null );
 		setNotice( null );
-	}, [ id ] );
+	}, [ slug ] );
 
 	useEffect( () => {
 		// If the selected fonts change, reset the selected fonts to install
@@ -108,10 +108,10 @@ function FontCollection( { id } ) {
 	}, [ notice ] );
 
 	const collectionFonts = useMemo(
-		() => selectedCollection?.data?.fontFamilies ?? [],
+		() => selectedCollection?.font_families ?? [],
 		[ selectedCollection ]
 	);
-	const collectionCategories = selectedCollection?.data?.categories ?? [];
+	const collectionCategories = selectedCollection?.categories ?? [];
 
 	const categories = [ DEFAULT_CATEGORY, ...collectionCategories ];
 
@@ -277,11 +277,11 @@ function FontCollection( { id } ) {
 
 			<Spacer margin={ 4 } />
 			{ ! renderConfirmDialog &&
-				! selectedCollection?.data?.fontFamilies &&
+				! selectedCollection?.font_families &&
 				! notice && <Spinner /> }
 
 			{ ! renderConfirmDialog &&
-				!! selectedCollection?.data?.fontFamilies?.length &&
+				!! selectedCollection?.font_families?.length &&
 				! fonts.length && (
 					<Text>
 						{ __(
@@ -302,10 +302,10 @@ function FontCollection( { id } ) {
 				<FontsGrid>
 					{ fonts.map( ( font ) => (
 						<FontCard
-							key={ font.slug }
-							font={ font }
+							key={ font.font_family_settings.slug }
+							font={ font.font_family_settings }
 							onClick={ () => {
-								setSelectedFont( font );
+								setSelectedFont( font.font_family_settings );
 							} }
 						/>
 					) ) }
diff --git a/packages/edit-site/src/components/global-styles/font-library-modal/index.js b/packages/edit-site/src/components/global-styles/font-library-modal/index.js
index 65a284560687cc..a68c42ec010413 100644
--- a/packages/edit-site/src/components/global-styles/font-library-modal/index.js
+++ b/packages/edit-site/src/components/global-styles/font-library-modal/index.js
@@ -31,10 +31,10 @@ const DEFAULT_TABS = [
 ];
 
 const tabsFromCollections = ( collections ) =>
-	collections.map( ( { id, name } ) => ( {
-		id,
+	collections.map( ( { slug, name } ) => ( {
+		id: slug,
 		title:
-			collections.length === 1 && id === 'default-font-collection'
+			collections.length === 1 && slug === 'default-font-collection'
 				? __( 'Install Fonts' )
 				: name,
 	} ) );
@@ -76,7 +76,7 @@ function FontLibraryModal( {
 								contents = <InstalledFonts />;
 								break;
 							default:
-								contents = <FontCollection id={ id } />;
+								contents = <FontCollection slug={ id } />;
 						}
 						return (
 							<Tabs.TabPanel
diff --git a/phpunit/tests/fonts/font-library/wpFontCollection/__construct.php b/phpunit/tests/fonts/font-library/wpFontCollection/__construct.php
index 380226ee8af8a3..8e9cf7bca08e5e 100644
--- a/phpunit/tests/fonts/font-library/wpFontCollection/__construct.php
+++ b/phpunit/tests/fonts/font-library/wpFontCollection/__construct.php
@@ -13,32 +13,50 @@
 class Tests_Fonts_WpFontCollection_Construct extends WP_UnitTestCase {
 
 	public function test_should_initialize_data() {
-		$property = new ReflectionProperty( WP_Font_Collection::class, 'config' );
-		$property->setAccessible( true );
+		$slug = new ReflectionProperty( WP_Font_Collection::class, 'slug' );
+		$slug->setAccessible( true );
 
-		$config          = array(
+		$name = new ReflectionProperty( WP_Font_Collection::class, 'name' );
+		$name->setAccessible( true );
+
+		$description = new ReflectionProperty( WP_Font_Collection::class, 'description' );
+		$description->setAccessible( true );
+
+		$src = new ReflectionProperty( WP_Font_Collection::class, 'src' );
+		$src->setAccessible( true );
+
+		$config     = array(
 			'slug'        => 'my-collection',
 			'name'        => 'My Collection',
 			'description' => 'My collection description',
 			'src'         => 'my-collection-data.json',
 		);
-		$font_collection = new WP_Font_Collection( $config );
+		$collection = new WP_Font_Collection( $config );
 
-		$actual = $property->getValue( $font_collection );
-		$property->setAccessible( false );
+		$actual_slug = $slug->getValue( $collection );
+		$this->assertSame( 'my-collection', $actual_slug, 'Provided slug and initialized slug should match.' );
+		$slug->setAccessible( false );
 
-		$this->assertSame( $config, $actual );
+		$actual_name = $name->getValue( $collection );
+		$this->assertSame( 'My Collection', $actual_name, 'Provided name and initialized name should match.' );
+		$name->setAccessible( false );
+
+		$actual_description = $description->getValue( $collection );
+		$this->assertSame( 'My collection description', $actual_description, 'Provided description and initialized description should match.' );
+		$description->setAccessible( false );
+
+		$actual_src = $src->getValue( $collection );
+		$this->assertSame( 'my-collection-data.json', $actual_src, 'Provided src and initialized src should match.' );
+		$src->setAccessible( false );
 	}
 
 	/**
-	 * @dataProvider data_should_throw_exception
+	 * @dataProvider data_should_do_ti_wrong
 	 *
 	 * @param mixed  $config Config of the font collection.
-	 * @param string $expected_exception_message Expected exception message.
 	 */
-	public function test_should_throw_exception( $config, $expected_exception_message ) {
-		$this->expectException( 'Exception' );
-		$this->expectExceptionMessage( $expected_exception_message );
+	public function test_should_do_ti_wrong( $config ) {
+		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::is_config_valid' );
 		new WP_Font_Collection( $config );
 	}
 
@@ -47,7 +65,7 @@ public function test_should_throw_exception( $config, $expected_exception_messag
 	 *
 	 * @return array
 	 */
-	public function data_should_throw_exception() {
+	public function data_should_do_ti_wrong() {
 		return array(
 			'no id'                           => array(
 				array(
@@ -55,27 +73,22 @@ public function data_should_throw_exception() {
 					'description' => 'My collection description',
 					'src'         => 'my-collection-data.json',
 				),
-				'Font Collection config slug is required as a non-empty string.',
 			),
 
 			'no config'                       => array(
 				'',
-				'Font Collection config options is required as a non-empty array.',
 			),
 
 			'empty array'                     => array(
 				array(),
-				'Font Collection config options is required as a non-empty array.',
 			),
 
 			'boolean instead of config array' => array(
 				false,
-				'Font Collection config options is required as a non-empty array.',
 			),
 
 			'null instead of config array'    => array(
 				null,
-				'Font Collection config options is required as a non-empty array.',
 			),
 
 			'missing src'                     => array(
@@ -84,9 +97,7 @@ public function data_should_throw_exception() {
 					'name'        => 'My Collection',
 					'description' => 'My collection description',
 				),
-				'Font Collection config "src" option OR "data" option is required.',
 			),
-
 		);
 	}
 }
diff --git a/phpunit/tests/fonts/font-library/wpFontCollection/getConfig.php b/phpunit/tests/fonts/font-library/wpFontCollection/getConfig.php
index 5f1f082297d418..393de7d22614da 100644
--- a/phpunit/tests/fonts/font-library/wpFontCollection/getConfig.php
+++ b/phpunit/tests/fonts/font-library/wpFontCollection/getConfig.php
@@ -32,7 +32,7 @@ public function data_should_get_config() {
 		file_put_contents( $mock_file, '{"this is mock data":true}' );
 
 		return array(
-			'with a file' => array(
+			'with a file'        => array(
 				'config'        => array(
 					'slug'        => 'my-collection',
 					'name'        => 'My Collection',
@@ -45,7 +45,7 @@ public function data_should_get_config() {
 					'description' => 'My collection description',
 				),
 			),
-			'with a url'  => array(
+			'with a url'         => array(
 				'config'        => array(
 					'slug'        => 'my-collection-with-url',
 					'name'        => 'My Collection with URL',
@@ -58,12 +58,12 @@ public function data_should_get_config() {
 					'description' => 'My collection description',
 				),
 			),
-			'with data'   => array(
+			'with font_families' => array(
 				'config'        => array(
-					'slug'        => 'my-collection',
-					'name'        => 'My Collection',
-					'description' => 'My collection description',
-					'data'        => array( 'this is mock data' => true ),
+					'slug'          => 'my-collection',
+					'name'          => 'My Collection',
+					'description'   => 'My collection description',
+					'font_families' => array( array() ),
 				),
 				'expected_data' => array(
 					'slug'        => 'my-collection',
diff --git a/phpunit/tests/fonts/font-library/wpFontCollection/getConfigAndData.php b/phpunit/tests/fonts/font-library/wpFontCollection/getContent.php
similarity index 52%
rename from phpunit/tests/fonts/font-library/wpFontCollection/getConfigAndData.php
rename to phpunit/tests/fonts/font-library/wpFontCollection/getContent.php
index 885b0a0b9036cb..ab0e87cde000e7 100644
--- a/phpunit/tests/fonts/font-library/wpFontCollection/getConfigAndData.php
+++ b/phpunit/tests/fonts/font-library/wpFontCollection/getContent.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Test WP_Font_Collection::get_config_and_data().
+ * Test WP_Font_Collection::get_content().
  *
  * @package WordPress
  * @subpackage Font Library
@@ -8,9 +8,9 @@
  * @group fonts
  * @group font-library
  *
- * @covers WP_Font_Collection::get_config_and_data
+ * @covers WP_Font_Collection::get_content
  */
-class Tests_Fonts_WpFontCollection_GetConfigAndData extends WP_UnitTestCase {
+class Tests_Fonts_WpFontCollection_GetContent extends WP_UnitTestCase {
 
 	public function set_up() {
 		parent::set_up();
@@ -34,8 +34,8 @@ public function mock_request( $preempt, $args, $url ) {
 
 		// Mock the response body.
 		$mock_collection_data = array(
-			'fontFamilies' => 'mock',
-			'categories'   => 'mock',
+			'font_families' => array( 'mock' ),
+			'categories'    => array( 'mock' ),
 		);
 
 		return array(
@@ -47,14 +47,14 @@ public function mock_request( $preempt, $args, $url ) {
 	}
 
 	/**
-	 * @dataProvider data_should_get_config_and_data
+	 * @dataProvider data_should_get_content
 	 *
 	 * @param array $config Font collection config options.
-	 * @param array $expected_data Expected data.
+	 * @param array $expected_data Expected output data.
 	 */
-	public function test_should_get_config_and_data( $config, $expected_data ) {
+	public function test_should_get_content( $config, $expected_data ) {
 		$collection = new WP_Font_Collection( $config );
-		$this->assertSame( $expected_data, $collection->get_config_and_data() );
+		$this->assertSame( $expected_data, $collection->get_content() );
 	}
 
 	/**
@@ -62,12 +62,12 @@ public function test_should_get_config_and_data( $config, $expected_data ) {
 	 *
 	 * @return array[]
 	 */
-	public function data_should_get_config_and_data() {
+	public function data_should_get_content() {
 		$mock_file = wp_tempnam( 'my-collection-data-' );
-		file_put_contents( $mock_file, '{"this is mock data":true}' );
+		file_put_contents( $mock_file, '{"font_families":[ "mock" ], "categories":[ "mock" ] }' );
 
 		return array(
-			'with a file' => array(
+			'with a file'                           => array(
 				'config'        => array(
 					'slug'        => 'my-collection',
 					'name'        => 'My Collection',
@@ -75,13 +75,11 @@ public function data_should_get_config_and_data() {
 					'src'         => $mock_file,
 				),
 				'expected_data' => array(
-					'slug'        => 'my-collection',
-					'name'        => 'My Collection',
-					'description' => 'My collection description',
-					'data'        => array( 'this is mock data' => true ),
+					'font_families' => array( 'mock' ),
+					'categories'    => array( 'mock' ),
 				),
 			),
-			'with a url'  => array(
+			'with a url'                            => array(
 				'config'        => array(
 					'slug'        => 'my-collection-with-url',
 					'name'        => 'My Collection with URL',
@@ -89,27 +87,33 @@ public function data_should_get_config_and_data() {
 					'src'         => 'https://localhost/fonts/mock-font-collection.json',
 				),
 				'expected_data' => array(
-					'slug'        => 'my-collection-with-url',
-					'name'        => 'My Collection with URL',
-					'description' => 'My collection description',
-					'data'        => array(
-						'fontFamilies' => 'mock',
-						'categories'   => 'mock',
-					),
+					'font_families' => array( 'mock' ),
+					'categories'    => array( 'mock' ),
 				),
 			),
-			'with data'   => array(
+			'with font_families and categories'     => array(
 				'config'        => array(
-					'slug'        => 'my-collection',
-					'name'        => 'My Collection',
-					'description' => 'My collection description',
-					'data'        => array( 'this is mock data' => true ),
+					'slug'          => 'my-collection',
+					'name'          => 'My Collection',
+					'description'   => 'My collection description',
+					'font_families' => array( 'mock' ),
+					'categories'    => array( 'mock' ),
 				),
 				'expected_data' => array(
-					'slug'        => 'my-collection',
-					'name'        => 'My Collection',
-					'description' => 'My collection description',
-					'data'        => array( 'this is mock data' => true ),
+					'font_families' => array( 'mock' ),
+					'categories'    => array( 'mock' ),
+				),
+			),
+			'with font_families without categories' => array(
+				'config'        => array(
+					'slug'          => 'my-collection',
+					'name'          => 'My Collection',
+					'description'   => 'My collection description',
+					'font_families' => array( 'mock' ),
+				),
+				'expected_data' => array(
+					'font_families' => array( 'mock' ),
+					'categories'    => array(),
 				),
 			),
 		);
diff --git a/phpunit/tests/fonts/font-library/wpFontCollection/isConfigValid.php b/phpunit/tests/fonts/font-library/wpFontCollection/isConfigValid.php
new file mode 100644
index 00000000000000..7cfdfc829ab863
--- /dev/null
+++ b/phpunit/tests/fonts/font-library/wpFontCollection/isConfigValid.php
@@ -0,0 +1,103 @@
+<?php
+/**
+ * Test WP_Font_Collection::is_config_valid().
+ *
+ * @package WordPress
+ * @subpackage Font Library
+ *
+ * @group fonts
+ * @group font-library
+ *
+ * @covers WP_Font_Collection::is_config_valid
+ */
+class Tests_Fonts_WpFontCollection_IsConfigValid extends WP_UnitTestCase {
+
+	/**
+	 * @dataProvider data_is_config_valid
+	 *
+	 * @param array $config Font collection config options.
+	 */
+	public function test_is_config_valid( $config ) {
+		$this->assertTrue( WP_Font_Collection::is_config_valid( $config ) );
+	}
+
+	public function data_is_config_valid() {
+		return array(
+			'with src'           => array(
+				'config' => array(
+					'slug'        => 'my-collection',
+					'name'        => 'My Collection',
+					'description' => 'My collection description',
+					'src'         => 'my-collection-data.json',
+				),
+			),
+			'with font families' => array(
+				'config' => array(
+					'slug'          => 'my-collection',
+					'name'          => 'My Collection',
+					'description'   => 'My collection description',
+					'font_families' => array( 'mock' ),
+				),
+			),
+
+		);
+	}
+
+	/**
+	 * @dataProvider data_is_config_valid_should_call_doing_ti_wrong
+	 *
+	 * @param mixed  $config Config of the font collection.
+	 */
+	public function test_is_config_valid_should_call_doing_ti_wrong( $config ) {
+		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::is_config_valid', 'Should call _doing_it_wrong if the config is not valid.' );
+		$this->assertFalse( WP_Font_Collection::is_config_valid( $config ), 'Should return false if the config is not valid.' );
+	}
+
+	public function data_is_config_valid_should_call_doing_ti_wrong() {
+		return array(
+			'with missing slug'               => array(
+				'config' => array(
+					'name'        => 'My Collection',
+					'description' => 'My collection description',
+					'src'         => 'my-collection-data.json',
+				),
+			),
+			'with missing name'               => array(
+				'config' => array(
+					'slug'        => 'my-collection',
+					'description' => 'My collection description',
+					'src'         => 'my-collection-data.json',
+				),
+			),
+			'with missing src'                => array(
+				'config' => array(
+					'slug'        => 'my-collection',
+					'name'        => 'My Collection',
+					'description' => 'My collection description',
+				),
+			),
+			'with both src and font_families' => array(
+				'config' => array(
+					'slug'          => 'my-collection',
+					'name'          => 'My Collection',
+					'description'   => 'My collection description',
+					'src'           => 'my-collection-data.json',
+					'font_families' => array( 'mock' ),
+				),
+			),
+			'without src or font_families'    => array(
+				'config' => array(
+					'slug'        => 'my-collection',
+					'name'        => 'My Collection',
+					'description' => 'My collection description',
+				),
+			),
+			'with empty config'               => array(
+				'config' => array(),
+			),
+			'without an array'                => array(
+				'config' => 'not an array',
+			),
+		);
+	}
+}
diff --git a/phpunit/tests/fonts/font-library/wpFontFamily/__construct.php b/phpunit/tests/fonts/font-library/wpFontFamily/__construct.php
index 3a1e387c3651b2..cee0628dad3103 100644
--- a/phpunit/tests/fonts/font-library/wpFontFamily/__construct.php
+++ b/phpunit/tests/fonts/font-library/wpFontFamily/__construct.php
@@ -30,11 +30,11 @@ public function test_should_initialize_data() {
 	}
 
 	/**
-	 * @dataProvider data_should_throw_exception
+	 * @dataProvider data_should_do_it_wrong
 	 *
 	 * @param mixed $font_data Data to test.
 	 */
-	public function test_should_throw_exception( $font_data ) {
+	public function test_should_do_it_wrong( $font_data ) {
 		$this->expectException( 'Exception' );
 		$this->expectExceptionMessage( 'Font family data is missing the slug.' );
 
@@ -46,7 +46,7 @@ public function test_should_throw_exception( $font_data ) {
 	 *
 	 * @return array
 	 */
-	public function data_should_throw_exception() {
+	public function data_should_do_it_wrong() {
 		return array(
 			'no slug'                  => array(
 				array(
diff --git a/phpunit/tests/fonts/font-library/wpFontLibrary/registerFontCollection.php b/phpunit/tests/fonts/font-library/wpFontLibrary/registerFontCollection.php
index a7ea2870957e9d..b06ae3c8d53548 100644
--- a/phpunit/tests/fonts/font-library/wpFontLibrary/registerFontCollection.php
+++ b/phpunit/tests/fonts/font-library/wpFontLibrary/registerFontCollection.php
@@ -29,9 +29,9 @@ public function test_should_return_error_if_slug_is_missing() {
 			'description' => 'My Collection Description',
 			'src'         => 'my-collection-data.json',
 		);
-		$this->expectException( 'Exception' );
-		$this->expectExceptionMessage( 'Font Collection config slug is required as a non-empty string.' );
-		WP_Font_Library::register_font_collection( $config );
+		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::is_config_valid' );
+		$collection = WP_Font_Library::register_font_collection( $config );
+		$this->assertWPError( $collection, 'A WP_Error should be returned.' );
 	}
 
 	public function test_should_return_error_if_name_is_missing() {
@@ -40,16 +40,16 @@ public function test_should_return_error_if_name_is_missing() {
 			'description' => 'My Collection Description',
 			'src'         => 'my-collection-data.json',
 		);
-		$this->expectException( 'Exception' );
-		$this->expectExceptionMessage( 'Font Collection config name is required as a non-empty string.' );
-		WP_Font_Library::register_font_collection( $config );
+		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::is_config_valid' );
+		$collection = WP_Font_Library::register_font_collection( $config );
+		$this->assertWPError( $collection, 'A WP_Error should be returned.' );
 	}
 
 	public function test_should_return_error_if_config_is_empty() {
 		$config = array();
-		$this->expectException( 'Exception' );
-		$this->expectExceptionMessage( 'Font Collection config options is required as a non-empty array.' );
-		WP_Font_Library::register_font_collection( $config );
+		$this->setExpectedIncorrectUsage( 'WP_Font_Collection::is_config_valid' );
+		$collection = WP_Font_Library::register_font_collection( $config );
+		$this->assertWPError( $collection, 'A WP_Error should be returned.' );
 	}
 
 	public function test_should_return_error_if_slug_is_repeated() {
diff --git a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController.php b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController.php
new file mode 100644
index 00000000000000..164f88f3f7b4b2
--- /dev/null
+++ b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController.php
@@ -0,0 +1,163 @@
+<?php
+/**
+ * Unit tests covering WP_REST_Font_Collections_Controller functionality.
+ *
+ * @package WordPress
+ * @subpackage REST_API
+ * @since 6.5.0
+ *
+ * @group restapi
+ *
+ * @coversDefaultClass WP_REST_Font_Collections_Controller
+ */
+class WP_REST_Font_Collections_Controller_Test extends WP_Test_REST_Controller_Testcase {
+	protected static $admin_id;
+	protected static $editor_id;
+	protected static $mock_file;
+
+
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$admin_id  = $factory->user->create(
+			array(
+				'role' => 'administrator',
+			)
+		);
+		self::$editor_id = $factory->user->create(
+			array(
+				'role' => 'editor',
+			)
+		);
+		$mock_file       = wp_tempnam( 'my-collection-data-' );
+		file_put_contents( $mock_file, '{"font_families": [ "mock" ], "categories": [ "mock" ] }' );
+
+		wp_register_font_collection(
+			array(
+				'name' => 'My Collection',
+				'slug' => 'mock-col-slug',
+				'src'  => $mock_file,
+			)
+		);
+	}
+
+	public static function wpTearDownAfterClass() {
+		self::delete_user( self::$admin_id );
+		self::delete_user( self::$editor_id );
+		wp_unregister_font_collection( 'mock-col-slug' );
+	}
+
+
+	/**
+	 * @covers WP_REST_Font_Collections_Controller::register_routes
+	 */
+	public function test_register_routes() {
+		$routes = rest_get_server()->get_routes();
+		$this->assertCount( 1, $routes['/wp/v2/font-collections'], 'Rest server has not the collections path initialized.' );
+		$this->assertCount( 1, $routes['/wp/v2/font-collections/(?P<slug>[\/\w-]+)'], 'Rest server has not the collection path initialized.' );
+
+		$this->assertArrayHasKey( 'GET', $routes['/wp/v2/font-collections'][0]['methods'], 'Rest server has not the GET method for collections intialized.' );
+		$this->assertArrayHasKey( 'GET', $routes['/wp/v2/font-collections/(?P<slug>[\/\w-]+)'][0]['methods'], 'Rest server has not the GET method for collection intialized.' );
+	}
+
+	/**
+	 * @covers WP_REST_Font_Collections_Controller::get_items
+	 */
+	public function test_get_items() {
+		wp_set_current_user( self::$admin_id );
+		$request  = new WP_REST_Request( 'GET', '/wp/v2/font-collections' );
+		$response = rest_get_server()->dispatch( $request );
+		$content  = $response->get_data();
+		$this->assertIsArray( $content );
+		$this->assertEquals( 200, $response->get_status() );
+	}
+
+	/**
+	 * @covers WP_REST_Font_Collections_Controller::get_item
+	 */
+	public function test_get_item() {
+		wp_set_current_user( self::$admin_id );
+		$request  = new WP_REST_Request( 'GET', '/wp/v2/font-collections/mock-col-slug' );
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertEquals( 200, $response->get_status(), 'Response code is not 200' );
+
+		$response_data = $response->get_data();
+		$this->assertArrayHasKey( 'name', $response_data, 'Response data does not have the name key.' );
+		$this->assertArrayHasKey( 'slug', $response_data, 'Response data does not have the slug key.' );
+		$this->assertArrayHasKey( 'description', $response_data, 'Response data does not have the description key.' );
+		$this->assertArrayHasKey( 'font_families', $response_data, 'Response data does not have the font_families key.' );
+		$this->assertArrayHasKey( 'categories', $response_data, 'Response data does not have the categories key.' );
+
+		$this->assertIsString( $response_data['name'], 'name is not a string.' );
+		$this->assertIsString( $response_data['slug'], 'slug is not a string.' );
+		$this->assertIsString( $response_data['description'], 'description is not a string.' );
+
+		$this->assertIsArray( $response_data['font_families'], 'font_families is not an array.' );
+		$this->assertIsArray( $response_data['categories'], 'categories is not an array.' );
+	}
+
+	/**
+	 * @covers WP_REST_Font_Collections_Controller::get_item
+	 */
+	public function test_get_item_invalid_slug() {
+		wp_set_current_user( self::$admin_id );
+		$request  = new WP_REST_Request( 'GET', '/wp/v2/font-collections/non-existing-collection' );
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertErrorResponse( 'font_collection_not_found', $response, 404 );
+	}
+
+	/**
+	 * @covers WP_REST_Font_Collections_Controller::get_item
+	 */
+	public function test_get_item_invalid_id_permission() {
+		$request = new WP_REST_Request( 'GET', '/wp/v2/font-collections/mock-col-slug' );
+
+		wp_set_current_user( 0 );
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertErrorResponse( 'rest_cannot_read', $response, 401, 'Response code should be 401 for non-authenticated users.' );
+
+		wp_set_current_user( self::$editor_id );
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertErrorResponse( 'rest_cannot_read', $response, 403, 'Response code should be 403 for users without the right permissions.' );
+	}
+
+	/**
+	 * @doesNotPerformAssertions
+	 */
+	public function test_context_param() {
+		// Controller does not use get_context_param().
+	}
+
+	/**
+	 * @doesNotPerformAssertions
+	 */
+	public function test_create_item() {
+		// Controller does not use test_create_item().
+	}
+
+	/**
+	 * @doesNotPerformAssertions
+	 */
+	public function test_update_item() {
+		// Controller does not use test_update_item().
+	}
+
+	/**
+	 * @doesNotPerformAssertions
+	 */
+	public function test_delete_item() {
+		// Controller does not use test_delete_item().
+	}
+
+	/**
+	 * @doesNotPerformAssertions
+	 */
+	public function test_prepare_item() {
+		// Controller does not use test_prepare_item().
+	}
+
+	/**
+	 * @doesNotPerformAssertions
+	 */
+	public function test_get_item_schema() {
+		// Controller does not use test_get_item_schema().
+	}
+}
diff --git a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/base.php b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/base.php
deleted file mode 100644
index 2469d71dc79ce8..00000000000000
--- a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/base.php
+++ /dev/null
@@ -1,42 +0,0 @@
-<?php
-/**
- * Test Case for WP_REST_Font_Collections_Controller tests.
- *
- * @package WordPress
- * @subpackage Font Library
- */
-abstract class WP_REST_Font_Collections_Controller_UnitTestCase extends WP_UnitTestCase {
-
-	/**
-	 * Fonts directory.
-	 *
-	 * @var string
-	 */
-	protected static $fonts_dir;
-
-
-	public function set_up() {
-		parent::set_up();
-
-		// Create a user with administrator role.
-		$admin_id = $this->factory->user->create(
-			array(
-				'role' => 'administrator',
-			)
-		);
-		wp_set_current_user( $admin_id );
-	}
-
-	/**
-	 * Tear down each test method.
-	 */
-	public function tear_down() {
-		parent::tear_down();
-
-		// Reset $collections static property of WP_Font_Library class.
-		$reflection = new ReflectionClass( 'WP_Font_Library' );
-		$property   = $reflection->getProperty( 'collections' );
-		$property->setAccessible( true );
-		$property->setValue( null, array() );
-	}
-}
diff --git a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollection.php b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollection.php
deleted file mode 100644
index c9d003389997b4..00000000000000
--- a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollection.php
+++ /dev/null
@@ -1,126 +0,0 @@
-<?php
-/**
- * Test WP_REST_Font_Collections_Controller::get_font_collection().
- *
- * @package WordPress
- * @subpackage Font Library
- *
- * @group fonts
- * @group font-library
- *
- * @covers WP_REST_Font_Collections_Controller::get_font_collection
- */
-
-class Tests_Fonts_WPRESTFontCollectionsController_GetFontCollection extends WP_REST_Font_Collections_Controller_UnitTestCase {
-
-	/**
-	 * Register mock collections.
-	 */
-	public function set_up() {
-		parent::set_up();
-		// Mock font collection data file.
-		$mock_file = wp_tempnam( 'one-collection-' );
-		file_put_contents( $mock_file, '{"this is mock data":true}' );
-		// Mock the wp_remote_request() function.
-		add_filter( 'pre_http_request', array( $this, 'mock_request' ), 10, 3 );
-
-		$config_with_file = array(
-			'slug'        => 'one-collection',
-			'name'        => 'One Font Collection',
-			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
-			'src'         => $mock_file,
-		);
-		wp_register_font_collection( $config_with_file );
-
-		$config_with_url = array(
-			'slug'        => 'collection-with-url',
-			'name'        => 'Another Font Collection',
-			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
-			'src'         => 'https://wordpress.org/fonts/mock-font-collection.json',
-		);
-
-		wp_register_font_collection( $config_with_url );
-
-		$config_with_non_existing_file = array(
-			'slug'        => 'collection-with-non-existing-file',
-			'name'        => 'Another Font Collection',
-			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
-			'src'         => '/home/non-existing-file.json',
-		);
-
-		wp_register_font_collection( $config_with_non_existing_file );
-
-		$config_with_non_existing_url = array(
-			'slug'        => 'collection-with-non-existing-url',
-			'name'        => 'Another Font Collection',
-			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
-			'src'         => 'https://non-existing-url-1234x.com.ar/fake-path/missing-file.json',
-		);
-
-		wp_register_font_collection( $config_with_non_existing_url );
-	}
-
-	public function mock_request( $preempt, $args, $url ) {
-		// Check if it's the URL you want to mock.
-		if ( 'https://wordpress.org/fonts/mock-font-collection.json' === $url ) {
-
-			// Mock the response body.
-			$mock_collection_data = array(
-				'fontFamilies' => 'mock',
-				'categories'   => 'mock',
-			);
-
-			return array(
-				'body'     => json_encode( $mock_collection_data ),
-				'response' => array(
-					'code' => 200,
-				),
-			);
-		}
-
-		// For any other URL, return false which ensures the request is made as usual (or you can return other mock data).
-		return false;
-	}
-
-	public function tear_down() {
-		// Remove the mock to not affect other tests.
-		remove_filter( 'pre_http_request', array( $this, 'mock_request' ) );
-
-		parent::tear_down();
-	}
-
-	public function test_get_font_collection_from_file() {
-		$request  = new WP_REST_Request( 'GET', '/wp/v2/font-collections/one-collection' );
-		$response = rest_get_server()->dispatch( $request );
-		$data     = $response->get_data();
-		$this->assertSame( 200, $response->get_status(), 'The response status is not 200.' );
-		$this->assertArrayHasKey( 'data', $data, 'The response data does not have the key with the file data.' );
-		$this->assertSame( array( 'this is mock data' => true ), $data['data'], 'The response data does not have the expected file data.' );
-	}
-
-	public function test_get_font_collection_from_url() {
-		$request  = new WP_REST_Request( 'GET', '/wp/v2/font-collections/collection-with-url' );
-		$response = rest_get_server()->dispatch( $request );
-		$data     = $response->get_data();
-		$this->assertSame( 200, $response->get_status(), 'The response status is not 200.' );
-		$this->assertArrayHasKey( 'data', $data, 'The response data does not have the key with the file data.' );
-	}
-
-	public function test_get_non_existing_collection_should_return_404() {
-		$request  = new WP_REST_Request( 'GET', '/wp/v2/font-collections/non-existing-collection-id' );
-		$response = rest_get_server()->dispatch( $request );
-		$this->assertSame( 404, $response->get_status() );
-	}
-
-	public function test_get_non_existing_file_should_return_500() {
-		$request  = new WP_REST_Request( 'GET', '/wp/v2/font-collections/collection-with-non-existing-file' );
-		$response = rest_get_server()->dispatch( $request );
-		$this->assertSame( 500, $response->get_status() );
-	}
-
-	public function test_get_non_existing_url_should_return_500() {
-		$request  = new WP_REST_Request( 'GET', '/wp/v2/font-collections/collection-with-non-existing-url' );
-		$response = rest_get_server()->dispatch( $request );
-		$this->assertSame( 500, $response->get_status() );
-	}
-}
diff --git a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollections.php b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollections.php
deleted file mode 100644
index 0a8d24e8f392ba..00000000000000
--- a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/getFontCollections.php
+++ /dev/null
@@ -1,45 +0,0 @@
-<?php
-/**
- * Test WP_REST_Font_Collections_Controller::get_font_collections().
- *
- * @package WordPress
- * @subpackage Font Library
- *
- * @group fonts
- * @group font-library
- *
- * @covers WP_REST_Font_Collections_Controller::get_font_collections
- */
-
-class Tests_Fonts_WPRESTFontCollectionsController_GetFontCollections extends WP_REST_Font_Collections_Controller_UnitTestCase {
-
-	public function test_get_font_collections_with_no_collection_registered() {
-		$request  = new WP_REST_Request( 'GET', '/wp/v2/font-collections' );
-		$response = rest_get_server()->dispatch( $request );
-		$this->assertSame( 200, $response->get_status() );
-		$this->assertSame( array(), $response->get_data() );
-	}
-
-	public function test_get_font_collections() {
-		// Mock font collection data file.
-		$mock_file = wp_tempnam( 'my-collection-data-' );
-		file_put_contents( $mock_file, '{"this is mock data":true}' );
-
-		// Add a font collection.
-		$config = array(
-			'slug'        => 'my-font-collection',
-			'name'        => 'My Font Collection',
-			'description' => 'Demo about how to a font collection to your WordPress Font Library.',
-			'src'         => $mock_file,
-		);
-		wp_register_font_collection( $config );
-
-		$request  = new WP_REST_Request( 'GET', '/wp/v2/font-collections' );
-		$response = rest_get_server()->dispatch( $request );
-		$data     = $response->get_data();
-		$this->assertSame( 200, $response->get_status(), 'The response status is not 200.' );
-		$this->assertCount( 1, $data, 'The response data is not an array with one element.' );
-		$this->assertArrayHasKey( 'slug', $data[0], 'The response data does not have the key with the collection slug.' );
-		$this->assertArrayHasKey( 'name', $data[0], 'The response data does not have the key with the collection name.' );
-	}
-}
diff --git a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/registerRoutes.php b/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/registerRoutes.php
deleted file mode 100644
index fb100a400fb4cf..00000000000000
--- a/phpunit/tests/fonts/font-library/wpRestFontCollectionsController/registerRoutes.php
+++ /dev/null
@@ -1,24 +0,0 @@
-<?php
-/**
- * Test WP_REST_Font_Collections_Controller::register_routes().
- *
- * @package WordPress
- * @subpackage Font Library
- *
- * @group fonts
- * @group font-library
- *
- * @covers WP_REST_Font_Collections_Controller::register_routes
- */
-
-class Tests_Fonts_WPRESTFontCollectionsController_RegisterRoutes extends WP_UnitTestCase {
-
-	public function test_register_routes() {
-		$routes = rest_get_server()->get_routes();
-		$this->assertCount( 1, $routes['/wp/v2/font-collections'], 'Rest server has not the collections path initialized.' );
-		$this->assertCount( 1, $routes['/wp/v2/font-collections/(?P<slug>[\/\w-]+)'], 'Rest server has not the collection path initialized.' );
-
-		$this->assertArrayHasKey( 'GET', $routes['/wp/v2/font-collections'][0]['methods'], 'Rest server has not the GET method for collections intialized.' );
-		$this->assertArrayHasKey( 'GET', $routes['/wp/v2/font-collections/(?P<slug>[\/\w-]+)'][0]['methods'], 'Rest server has not the GET method for collection intialized.' );
-	}
-}