Script Loader: Warn when a registered style has invalid path data and allow inlining empty stylesheets.

When a stylesheet is registered with a `path` that does not exist or which is not readable, then a `_doing_it_wrong()` is now issued. Previously, paths that did not exist were silently skipped; paths for empty styles were also needlessly skipped, since `wp_filesize()` also returns `0` for the failure case. 

Developed in WordPress#10653

Follow-up to [50836].

Props westonruter, jonsurrell, soyebsalar01.
See #52620.
Fixes #64447.


git-svn-id: https://develop.svn.wordpress.org/trunk@61416 602fd350-edb4-49c9-b593-d223f7449a82

Author: westonruter

src/wp-includes/script-loader.php

@@ -3010,7 +3010,18 @@ function wp_maybe_inline_styles() {
 		$path = $wp_styles->get_data( $handle, 'path' );
 		if ( $path && $src ) {
 			$size = wp_filesize( $path );
-			if ( ! $size ) {
+			if ( 0 === $size && ! file_exists( $path ) ) {
+				_doing_it_wrong(
+					__FUNCTION__,
+					sprintf(
+						/* translators: 1: 'path', 2: filesystem path, 3: style handle */
+						__( 'Unable to read the "%1$s" key with value "%2$s" for stylesheet "%3$s".' ),
+						'path',
+						esc_html( $path ),
+						esc_html( $handle )
+					),
+					'7.0.0'
+				);
 				continue;
 			}
 			$styles[] = array(
@@ -3048,6 +3059,20 @@ static function ( $a, $b ) {
 			}
 
 			// Get the styles if we don't already have them.
+			if ( ! is_readable( $style['path'] ) ) {
+				_doing_it_wrong(
+					__FUNCTION__,
+					sprintf(
+						/* translators: 1: 'path', 2: filesystem path, 3: style handle */
+						__( 'Unable to read the "%1$s" key with value "%2$s" for stylesheet "%3$s".' ),
+						'path',
+						esc_html( $style['path'] ),
+						esc_html( $style['handle'] )
+					),
+					'7.0.0'
+				);
+				continue;
+			}
 			$style['css'] = file_get_contents( $style['path'] );
 
 			/*

tests/phpunit/tests/dependencies/styles.php

@@ -716,10 +716,12 @@ public function test_wp_maybe_inline_styles_multiple_runs() {
 
 	/**
 	 * @ticket 58394
+	 * @ticket 64447
 	 *
 	 * @covers ::wp_maybe_inline_styles
+	 * @expectedIncorrectUsage wp_maybe_inline_styles
 	 */
-	public function test_test_wp_maybe_inline_styles_missing_file() {
+	public function test_wp_maybe_inline_styles_missing_file() {
 		$filter = new MockAction();
 		add_filter( 'pre_wp_filesize', array( $filter, 'filter' ) );
 		$url = '/' . WPINC . '/css/invalid.css';
@@ -768,6 +770,70 @@ public function test_wp_maybe_inline_styles_no_path() {
 		$this->assertSame( $GLOBALS['wp_styles']->registered['test-handle']->src, $url );
 	}
 
+	/**
+	 * @ticket 64447
+	 *
+	 * @covers ::wp_maybe_inline_styles
+	 * @expectedIncorrectUsage wp_maybe_inline_styles
+	 */
+	public function test_wp_maybe_inline_styles_bad_path_with_file_size_provided() {
+		$style_path = '/css/invalid.css'; // Does not exist.
+
+		// This ensures the initial file size check is bypassed.
+		add_filter(
+			'pre_wp_filesize',
+			static function ( $size, $path ) use ( $style_path ) {
+				if ( str_contains( $path, $style_path ) ) {
+					$size = 1000;
+				}
+				return $size;
+			},
+			10,
+			2
+		);
+
+		$handle = 'test-handle';
+		$url    = '/' . WPINC . $style_path;
+		wp_register_style( $handle, $url );
+		wp_style_add_data( $handle, 'path', ABSPATH . WPINC . $style_path );
+		wp_enqueue_style( $handle );
+
+		wp_maybe_inline_styles();
+
+		$this->assertSame( $GLOBALS['wp_styles']->registered[ $handle ]->src, $url );
+	}
+
+	/**
+	 * @ticket 64447
+	 *
+	 * @covers ::wp_maybe_inline_styles
+	 */
+	public function test_wp_maybe_inline_styles_good_path_with_zero_file_size_provided() {
+		$style_path = '/css/classic-themes.css';
+
+		// This simulates the file having a zero size.
+		add_filter(
+			'pre_wp_filesize',
+			static function ( $size, $path ) use ( $style_path ) {
+				if ( str_contains( $path, $style_path ) ) {
+					$size = 0;
+				}
+				return $size;
+			},
+			10,
+			2
+		);
+
+		$handle = 'test-handle';
+		wp_register_style( $handle, '/' . WPINC . $style_path );
+		wp_style_add_data( $handle, 'path', ABSPATH . WPINC . $style_path );
+		wp_enqueue_style( $handle );
+
+		wp_maybe_inline_styles();
+
+		$this->assertFalse( $GLOBALS['wp_styles']->registered[ $handle ]->src );
+	}
+
 	/**
 	 * @ticket 63887
 	 */

tests/phpunit/tests/media.php

@@ -6677,6 +6677,10 @@ static function () {
 	 * @dataProvider data_provider_data_provider_to_test_wp_enqueue_img_auto_sizes_contain_css_fix
 	 */
 	public function test_wp_enqueue_img_auto_sizes_contain_css_fix( ?Closure $set_up, bool $expected, ?string $expected_deprecated = null ): void {
+		// These files are created as part of the build process, but the unit tests don't run the build prior to running unit tests on GHA.
+		self::touch( ABSPATH . WPINC . '/css/dist/block-library/style.css' );
+		self::touch( ABSPATH . WPINC . '/css/dist/block-library/common.css' );
+
 		if ( $set_up ) {
 			$set_up();
 		}

tests/phpunit/tests/template.php

@@ -1677,6 +1677,9 @@ function (): void {
 	 * @dataProvider data_wp_hoist_late_printed_styles
 	 */
 	public function test_wp_hoist_late_printed_styles( ?Closure $set_up, int $inline_size_limit, array $expected_styles ): void {
+		// `_print_emoji_detection_script()` assumes `wp-includes/js/wp-emoji-loader.js` is present:
+		self::touch( ABSPATH . WPINC . '/js/wp-emoji-loader.js' );
+
 		switch_theme( 'default' );
 		global $wp_styles;
 		$wp_styles = null;
@@ -1711,6 +1714,8 @@ static function () {
 			'wp-block-library',
 			wp_should_load_separate_core_block_assets() ? 'css/dist/block-library/common.css' : 'css/dist/block-library/style.css'
 		);
+		$this->ensure_style_asset_file_created( 'wp-block-library-theme', 'css/dist/block-library/theme.css' );
+
 		if ( wp_should_load_separate_core_block_assets() ) {
 			$this->ensure_style_asset_file_created( 'wp-block-separator', 'blocks/separator/style.css' );
 		}
@@ -1827,11 +1832,8 @@ private function ensure_style_asset_file_created( string $handle, string $relati
 		}
 		$dependency->src = includes_url( $relative_path );
 		$path            = ABSPATH . WPINC . '/' . $relative_path;
-		if ( ! file_exists( $path ) ) {
-			$dir = dirname( $path );
-			if ( ! file_exists( $dir ) ) {
-				mkdir( $dir, 0777, true );
-			}
+		self::touch( $path );
+		if ( 0 === filesize( $path ) ) {
 			file_put_contents( $path, "/* CSS for $handle */" );
 		}
 		wp_style_add_data( $handle, 'path', $path );