resourceloader: Track state of page-style modules

This allows dynamically loaded modules to depend on page-style modules
without it causing the page-style module to be loaded a second time.

* New method Module::getType() indicates whether a module is
  a page-style module or supposed to be dynamically loaded.

* Emit warning from addModuleStyles() when given a module that is
  not a page-style module (to be enforced later)

Bug: T92459
Bug: T87871
Change-Id: I8b6c6a10d965e73965f877c42e995d04202524f3

includes/OutputPage.php

@@ -2785,6 +2785,17 @@ class OutputPage extends ContextSource {
 				continue;
 			}
 
+			if ( $only === ResourceLoaderModule::TYPE_STYLES ) {
+				if ( $module->getType() !== ResourceLoaderModule::LOAD_STYLES ) {
+					$logger = $resourceLoader->getLogger();
+					$logger->debug( 'Unexpected general module "{module}" in styles queue.', [
+						'module' => $name,
+					] );
+				} else {
+					$links['states'][$name] = 'ready';
+				}
+			}
+
 			$sortedModules[$module->getSource()][$module->getGroup()][$name] = $module;
 		}
 

includes/resourceloader/ResourceLoaderFileModule.php

@@ -922,6 +922,28 @@ class ResourceLoaderFileModule extends ResourceLoaderModule {
 		return $this->targets;
 	}
 
+	/**
+	 * Get the module's load type.
+	 *
+	 * @since 1.28
+	 * @return string
+	 */
+	public function getType() {
+		$canBeStylesOnly = !(
+			// All options except 'styles', 'skinStyles' and 'debugRaw'
+			$this->scripts
+			|| $this->debugScripts
+			|| $this->templates
+			|| $this->languageScripts
+			|| $this->skinScripts
+			|| $this->dependencies
+			|| $this->messages
+			|| $this->skipFunction
+			|| $this->raw
+		);
+		return $canBeStylesOnly ? self::LOAD_STYLES : self::LOAD_GENERAL;
+	}
+
 	/**
 	 * Compile a LESS file into CSS.
 	 *

includes/resourceloader/ResourceLoaderModule.php

@@ -35,6 +35,12 @@ abstract class ResourceLoaderModule implements LoggerAwareInterface {
 	const TYPE_STYLES = 'styles';
 	const TYPE_COMBINED = 'combined';
 
+	# Desired load type
+	// Module only has styles (loaded via <style> or <link rel=stylesheet>)
+	const LOAD_STYLES = 'styles';
+	// Module may have other resources (loaded via mw.loader from a script)
+	const LOAD_GENERAL = 'general';
+
 	# sitewide core module like a skin file or jQuery component
 	const ORIGIN_CORE_SITEWIDE = 1;
 
@@ -343,6 +349,16 @@ abstract class ResourceLoaderModule implements LoggerAwareInterface {
 		return $this->targets;
 	}
 
+	/**
+	 * Get the module's load type.
+	 *
+	 * @since 1.28
+	 * @return string ResourceLoaderModule LOAD_* constant
+	 */
+	public function getType() {
+		return self::LOAD_GENERAL;
+	}
+
 	/**
 	 * Get the skip function.
 	 *

includes/resourceloader/ResourceLoaderSiteStylesModule.php

@@ -43,4 +43,11 @@ class ResourceLoaderSiteStylesModule extends ResourceLoaderWikiModule {
 		}
 		return $pages;
 	}
+
+	/**
+	 * @return string
+	 */
+	public function getType() {
+		return self::LOAD_STYLES;
+	}
 }

includes/resourceloader/ResourceLoaderUserCSSPrefsModule.php

@@ -83,4 +83,11 @@ class ResourceLoaderUserCSSPrefsModule extends ResourceLoaderModule {
 	public function getGroup() {
 		return 'private';
 	}
+
+	/**
+	 * @return string
+	 */
+	public function getType() {
+		return self::LOAD_STYLES;
+	}
 }

includes/resourceloader/ResourceLoaderWikiModule.php

@@ -321,7 +321,21 @@ class ResourceLoaderWikiModule extends ResourceLoaderModule {
 		return $this->titleInfo[$key];
 	}
 
+	/**
+	 * @return string
+	 */
 	public function getPosition() {
 		return $this->position;
 	}
+
+	/**
+	 * @since 1.28
+	 * @return string
+	 */
+	public function getType() {
+		// Check both because subclasses don't always pass pages via the constructor,
+		// they may also override getPages() instead, in which case we should keep
+		// defaulting to LOAD_GENERAL and allow them to override getType() separately.
+		return ( $this->styles && !$this->scripts ) ? self::LOAD_STYLES : self::LOAD_GENERAL;
+	}
 }