felixarntz · Jul 8, 2022 · Jun 22, 2022 · Jun 22, 2022 · Jun 22, 2022 · Jun 22, 2022
diff --git a/admin/load.php b/admin/load.php
@@ -135,22 +135,34 @@ function perflab_render_modules_page_field( $module_slug, $module_data, $module_
 			<?php echo esc_html( $module_data['name'] ); ?>
 		</legend>
 		<label for="<?php echo esc_attr( "{$base_id}_enabled" ); ?>">
-			<input type="checkbox" id="<?php echo esc_attr( "{$base_id}_enabled" ); ?>" name="<?php echo esc_attr( "{$base_name}[enabled]" ); ?>" aria-describedby="<?php echo esc_attr( "{$base_id}_description" ); ?>" value="1"<?php checked( $enabled ); ?>>
-			<?php
-			if ( $module_data['experimental'] ) {
-				printf(
-					/* translators: %s: module name */
-					__( 'Enable %s <strong>(experimental)</strong>', 'performance-lab' ),
-					esc_html( $module_data['name'] )
-				);
-			} else {
-				printf(
-					/* translators: %s: module name */
-					__( 'Enable %s', 'performance-lab' ),
-					esc_html( $module_data['name'] )
-				);
-			}
-			?>
+			<?php if ( perflab_can_load_module( $module_slug ) ) { ?>
+				<input type="checkbox" id="<?php echo esc_attr( "{$base_id}_enabled" ); ?>" name="<?php echo esc_attr( "{$base_name}[enabled]" ); ?>" aria-describedby="<?php echo esc_attr( "{$base_id}_description" ); ?>" value="1"<?php checked( $enabled ); ?>>
+				<?php
+				if ( $module_data['experimental'] ) {
+					printf(
+						/* translators: %s: module name */
+						__( 'Enable %s <strong>(experimental)</strong>', 'performance-lab' ),
+						esc_html( $module_data['name'] )
+					);
+				} else {
+					printf(
+						/* translators: %s: module name */
+						__( 'Enable %s', 'performance-lab' ),
+						esc_html( $module_data['name'] )
+					);
+				}
+				?>
+			<?php } else { ?>
+				<input type="checkbox" id="<?php echo esc_attr( "{$base_id}_enabled" ); ?>" aria-describedby="<?php echo esc_attr( "{$base_id}_description" ); ?>" disabled>
+				<input type="hidden" name="<?php echo esc_attr( "{$base_name}[enabled]" ); ?>" value="<?php echo $enabled ? '1' : '0'; ?>">
+				<?php
+					printf(
+						/* translators: %s: module name */
+						__( '%s is already part of your WordPress version and therefore cannot be loaded as part of the plugin.', 'performance-lab' ),
+						esc_html( $module_data['name'] )
+					);
+				?>
+			<?php } ?>
 		</label>
 		<p id="<?php echo esc_attr( "{$base_id}_description" ); ?>" class="description">
 			<?php echo esc_html( $module_data['description'] ); ?>

diff --git a/load.php b/load.php
@@ -137,6 +137,30 @@ function( $module_settings ) {
 	return $modules;
 }
 
+/**
+ * Gets the active and valid performance modules.
+ *
+ * @since n.e.x.t
+ *
+ * @param string $module Slug of the module.
+ * @return bool True if the module is active and valid, otherwise false.
+ */
+function perflab_is_valid_module( $module ) {
+
+	if ( empty( $module ) ) {
+		return false;
+	}
+
+	// Do not load module if no longer exists.
+	$module_file = plugin_dir_path( __FILE__ ) . 'modules/' . $module . '/load.php';
+	if ( ! file_exists( $module_file ) ) {
+		return false;
+	}
+
+	// Do not load module if it cannot be loaded, e.g. if it was already merged and is available in WordPress core.
+	return perflab_can_load_module( $module );
+}
+
 /**
  * Gets the content attribute for the generator tag for the Performance Lab plugin.
  *
@@ -145,12 +169,12 @@ function( $module_settings ) {
  * @since 1.1.0
  */
 function perflab_get_generator_content() {
-	$active_modules = perflab_get_active_modules();
+	$active_and_valid_modules = array_filter( perflab_get_active_modules(), 'perflab_is_valid_module' );
 
 	return sprintf(
 		'Performance Lab %1$s; modules: %2$s',
 		PERFLAB_VERSION,
-		implode( ', ', $active_modules )
+		implode( ', ', $active_and_valid_modules )
 	);
 }
 
@@ -169,29 +193,49 @@ function perflab_render_generator() {
 add_action( 'wp_head', 'perflab_render_generator' );
 
 /**
- * Loads the active performance modules.
+ * Checks whether the given module can be loaded in the current environment.
  *
- * @since 1.0.0
+ * @since n.e.x.t
+ *
+ * @param string $module Slug of the module.
+ * @return bool Whether the module can be loaded or not.
  */
-function perflab_load_active_modules() {
-	$active_modules = perflab_get_active_modules();
+function perflab_can_load_module( $module ) {
+	$module_load_file = plugin_dir_path( __FILE__ ) . 'modules/' . $module . '/can-load.php';
+
+	// If the `can-load.php` file does not exist, assume the module can be loaded.
+	if ( ! file_exists( $module_load_file ) ) {
+		return true;
+	}
 
-	if ( empty( $active_modules ) ) {
-		return;
+	// Require the file to get the closure for whether the module can load.
+	$module = require $module_load_file;
+
+	// If the `can-load.php` file is invalid and does not return a closure, assume the module can be loaded.
+	if ( ! is_callable( $module ) ) {
+		return true;
 	}
 
-	foreach ( $active_modules as $module ) {
-		// Do not load module if it no longer exists.
-		$module_file = plugin_dir_path( __FILE__ ) . 'modules/' . $module . '/load.php';
-		if ( ! file_exists( $module_file ) ) {
-			continue;
-		}
+	// Call the closure to determine whether the module can be loaded.
+	return (bool) $module();
+}
+
+/**
+ * Loads the active and valid performance modules.
+ *
+ * @since 1.0.0
+ * @since n.e.x.t Renamed to perflab_load_active_and_valid_modules().
+ */
+function perflab_load_active_and_valid_modules() {
+	$active_and_valid_modules = array_filter( perflab_get_active_modules(), 'perflab_is_valid_module' );
+
+	foreach ( $active_and_valid_modules as $module ) {
 
-		require_once $module_file;
+		require_once plugin_dir_path( __FILE__ ) . 'modules/' . $module . '/load.php';
 	}
 }
 
-perflab_load_active_modules();
+perflab_load_active_and_valid_modules();
 
 // Only load admin integration when in admin.
 if ( is_admin() ) {

diff --git a/modules/images/webp-uploads/can-load.php b/modules/images/webp-uploads/can-load.php
@@ -0,0 +1,11 @@
+<?php
+/**
+ * Can load function to determine if WebP Uploads module already marge in WordPress core.
+ *
+ * @since   n.e.x.t
+ * @package performance-lab
+ */
+
+return function() {
+	return ! function_exists( 'wp_image_use_alternate_mime_types' );
+};
diff --git a/tests/load-tests.php b/tests/load-tests.php
@@ -122,15 +122,18 @@ function( $module_settings ) {
 
 	public function test_perflab_get_generator_content() {
 		// Assert that it returns the current version and active modules.
-		$dummy_active_modules = array( 'images/a-module', 'object-cache/another-module' );
+		// For this test, set the active modules to all defaults but the last one.
+		$active_modules = require plugin_dir_path( PERFLAB_MAIN_FILE ) . 'default-enabled-modules.php';
+		array_pop( $active_modules );
 		add_filter(
 			'perflab_active_modules',
-			function() use ( $dummy_active_modules ) {
-				return $dummy_active_modules;
+			function() use ( $active_modules ) {
+				return $active_modules;
 			}
 		);
-		$expected = 'Performance Lab ' . PERFLAB_VERSION . '; modules: ' . implode( ', ', $dummy_active_modules );
-		$content  = perflab_get_generator_content();
+		$active_modules = array_filter( perflab_get_active_modules(), 'perflab_is_valid_module' );
+		$expected       = 'Performance Lab ' . PERFLAB_VERSION . '; modules: ' . implode( ', ', $active_modules );
+		$content        = perflab_get_generator_content();
 		$this->assertSame( $expected, $content );
 	}
 
@@ -148,6 +151,38 @@ public function test_perflab_render_generator() {
 		$this->assertContains( $expected, $output );
 	}
 
+	/**
+	 * @dataProvider data_perflab_can_load_module
+	 */
+	public function test_perflab_is_valid_module( $dummy_module, $expected_status ) {
+		$this->assertSame( $expected_status, perflab_is_valid_module( $dummy_module ) );
+	}
+
+	public function data_perflab_is_valid_module() {
+		return array(
+			array( '', false ),
+			array( '../tests/testdata/demo-modules/something/non-existing-module', false ),
+			array( '../tests/testdata/demo-modules/javascript/demo-module-1', false ),
+			array( '../tests/testdata/demo-modules/something/demo-module-2', true ),
+			array( '../tests/testdata/demo-modules/images/demo-module-3', true ),
+		);
+	}
+
+	/**
+	 * @dataProvider data_perflab_can_load_module
+	 */
+	public function test_perflab_can_load_module( $dummy_module, $expected_status ) {
+		$this->assertSame( $expected_status, perflab_can_load_module( $dummy_module ) );
+	}
+
+	public function data_perflab_can_load_module() {
+		return array(
+			array( '../tests/testdata/demo-modules/javascript/demo-module-1', false ),
+			array( '../tests/testdata/demo-modules/something/demo-module-2', true ),
+			array( '../tests/testdata/demo-modules/images/demo-module-3', true ),
+		);
+	}
+
 	private function get_expected_default_option() {
 		// This code is essentially copied over from the perflab_register_modules_setting() function.
 		$default_enabled_modules = require plugin_dir_path( PERFLAB_MAIN_FILE ) . 'default-enabled-modules.php';

diff --git a/tests/testdata/demo-modules/images/demo-module-3/can-load.php b/tests/testdata/demo-modules/images/demo-module-3/can-load.php
@@ -0,0 +1,9 @@
+<?php
+/**
+ * Can load function to determine if module already marge in WordPress core.
+ *
+ * @since   n.e.x.t
+ * @package performance-lab
+ */
+
+return '__return_true';
diff --git a/tests/testdata/demo-modules/javascript/demo-module-1/can-load.php b/tests/testdata/demo-modules/javascript/demo-module-1/can-load.php
@@ -0,0 +1,9 @@
+<?php
+/**
+ * Can load function to determine if module already marge in WordPress core.
+ *
+ * @since   n.e.x.t
+ * @package performance-lab
+ */
+
+return '__return_false';