exception: Inject wgShowExceptionDetails from Setup.php

Follows-up I8520d8cb16 and Ib941c22d6b7ec5f1b9, and adds an internal
setter for use by Setup.php, and for wmf-config:rpc/RunSingleJob.php
which is a use case for setting it after Setup.php but before most
code execution. Interact with a component owner instead of directly
maintaining state and providing a shared API through the Config object.

Change-Id: I5c3d4b11f4e0eb3906ccb5b5fe3979e026459859

includes/Rest/EntryPoint.php

@@ -12,6 +12,7 @@ use MediaWiki\Rest\BasicAccess\CompoundAuthorizer;
 use MediaWiki\Rest\BasicAccess\MWBasicAuthorizer;
 use MediaWiki\Rest\Reporter\MWErrorReporter;
 use MediaWiki\Rest\Validator\Validator;
+use MWExceptionRenderer;
 use RequestContext;
 use Title;
 use WebResponse;
@@ -110,7 +111,7 @@ class EntryPoint {
 		$conf = $services->getMainConfig();
 
 		$responseFactory = new ResponseFactory( self::getTextFormatters( $services ) );
-		$responseFactory->setSendExceptionBacktrace( $conf->get( 'ShowExceptionDetails' ) );
+		$responseFactory->setSendExceptionBacktrace( MWExceptionRenderer::shouldShowExceptionDetails() );
 
 		$cors = new CorsUtils(
 			new ServiceOptions(

includes/Setup.php

@@ -290,6 +290,7 @@ MediaWikiServices::allowGlobalInstance();
 // is complete.
 define( 'MW_SERVICE_BOOTSTRAP_COMPLETE', 1 );
 
+MWExceptionRenderer::setShowExceptionDetails( $wgShowExceptionDetails );
 MWExceptionHandler::installHandler( $wgLogExceptionBacktrace, $wgPropagateErrors );
 
 // Non-trivial validation of: $wgServer

includes/api/ApiMain.php

@@ -1304,13 +1304,11 @@ class ApiMain extends ApiBase {
 		} elseif ( $type !== 'error' ) {
 			// None of the rest have any messages for non-error types
 		} else {
-			// Something is seriously wrong
-			$config = $this->getConfig();
 			// TODO: Avoid embedding arbitrary class names in the error code.
 			$class = preg_replace( '#^Wikimedia\\\Rdbms\\\#', '', get_class( $e ) );
 			$code = 'internal_api_error_' . $class;
 			$data = [ 'errorclass' => get_class( $e ) ];
-			if ( $config->get( MainConfigNames::ShowExceptionDetails ) ) {
+			if ( MWExceptionRenderer::shouldShowExceptionDetails() ) {
 				if ( $e instanceof ILocalizedException ) {
 					$msg = $e->getMessageObject();
 				} elseif ( $e instanceof MessageSpecifier ) {

includes/exception/MWException.php

@@ -17,8 +17,6 @@
  *
  * @file
  */
-use MediaWiki\MainConfigNames;
-use MediaWiki\MediaWikiServices;
 
 /**
  * MediaWiki exception
@@ -101,29 +99,16 @@ class MWException extends Exception {
 		return $res;
 	}
 
-	private function shouldShowExceptionDetails(): bool {
-		// NOTE: keep in sync with MWExceptionRenderer::shouldShowExceptionDetails
-		if ( MediaWikiServices::hasInstance() ) {
-			$services = MediaWikiServices::getInstance();
-			if ( $services->hasService( 'MainConfig' ) ) {
-				return $services->getMainConfig()->get( MainConfigNames::ShowExceptionDetails );
-			}
-		}
-		global $wgShowExceptionDetails;
-		return $wgShowExceptionDetails ?? false;
-	}
-
 	/**
-	 * If $wgShowExceptionDetails is true, return a HTML message with a
-	 * backtrace to the error, otherwise show a message to ask to set it to true
-	 * to show that information.
+	 * Format an HTML message for the current exception object.
+	 *
 	 *
 	 * @stable to override
-	 *
-	 * @return string Html to output
+	 * @todo Rarely used, remove in favour of generic MWExceptionRenderer
+	 * @return string HTML to output
 	 */
 	public function getHTML() {
-		if ( self::shouldShowExceptionDetails() ) {
+		if ( MWExceptionRenderer::shouldShowExceptionDetails() ) {
 			return '<p>' . nl2br( htmlspecialchars( MWExceptionHandler::getLogMessage( $this ) ) ) .
 			'</p><p>Backtrace:</p><p>' .
 			nl2br( htmlspecialchars( MWExceptionHandler::getRedactedTraceAsString( $this ) ) ) .
@@ -149,16 +134,14 @@ class MWException extends Exception {
 	}
 
 	/**
-	 * Get the text to display when reporting the error on the command line.
-	 * If $wgShowExceptionDetails is true, return a text message with a
-	 * backtrace to the error.
+	 * Format plain text message for the current exception object.
 	 *
 	 * @stable to override
-	 *
+	 * @todo Rarely used, remove in favour of generic MWExceptionRenderer
 	 * @return string
 	 */
 	public function getText() {
-		if ( self::shouldShowExceptionDetails() ) {
+		if ( MWExceptionRenderer::shouldShowExceptionDetails() ) {
 			return MWExceptionHandler::getLogMessage( $this ) .
 			"\nBacktrace:\n" . MWExceptionHandler::getRedactedTraceAsString( $this ) . "\n";
 		} else {

includes/exception/MWExceptionRenderer.php

@@ -34,19 +34,30 @@ class MWExceptionRenderer {
 	public const AS_RAW = 1; // show as text
 	public const AS_PRETTY = 2; // show as HTML
 
-	private static function shouldShowExceptionDetails(): bool {
-		// NOTE: keep in sync with MWException::shouldShowExceptionDetails
-		if ( MediaWikiServices::hasInstance() ) {
-			$services = MediaWikiServices::getInstance();
-			if ( $services->hasService( 'MainConfig' ) ) {
-				return $services->getMainConfig()->get( MainConfigNames::ShowExceptionDetails );
-			}
-		}
+	/**
+	 * Whether to print exceptino details.
+	 *
+	 * The default is configured by $wgShowExceptionDetails.
+	 * May be changed at runtime via MWExceptionRenderer::setShowExceptionDetails().
+	 *
+	 * @see MainConfigNames::ShowExceptionDetails
+	 */
+	private static $showExceptionDetails = false;
 
-		// Shouldn't happen, since Setup.php calls MediaWikiServices::allowGlobalInstance() before
-		// MWExceptionHandler::installHandler(). But we shouldn't just crash and if it does,
-		// we should return nicely and continue to report the original error.
-		return false;
+	/**
+	 * @internal For use within core wiring only.
+	 * @return bool
+	 */
+	public static function shouldShowExceptionDetails(): bool {
+		return self::$showExceptionDetails;
+	}
+
+	/**
+	 * @param bool $showDetails
+	 * @internal For use by Setup.php and other internal use cases.
+	 */
+	public static function setShowExceptionDetails( bool $showDetails ): void {
+		self::$showExceptionDetails = $showDetails;
 	}
 
 	/**
@@ -189,15 +200,12 @@ class MWExceptionRenderer {
 	}
 
 	/**
-	 * If $wgShowExceptionDetails is true, return a HTML message with a
-	 * backtrace to the error, otherwise show a message to ask to set it to true
-	 * to show that information.
+	 * Format an HTML message for the given exception object.
 	 *
 	 * @param Throwable $e
 	 * @return string Html to output
 	 */
 	public static function getHTML( Throwable $e ) {
-		// XXX: do we need a parameter to control inclusion of exception details?
 		if ( self::shouldShowExceptionDetails() ) {
 			$html = Html::errorBox( "<p>" .
 				nl2br( htmlspecialchars( MWExceptionHandler::getLogMessage( $e ) ) ) .

includes/installer/DatabaseInstaller.php

@@ -425,6 +425,7 @@ abstract class DatabaseInstaller {
 			$up->doUpdates();
 			$up->purgeCache();
 		} catch ( MWException $e ) {
+			// TODO: Remove special casing in favour of MWExceptionRenderer
 			echo "\nAn error occurred:\n";
 			echo $e->getText();
 			$ret = false;

includes/resourceloader/ResourceLoader.php

@@ -1014,10 +1014,7 @@ class ResourceLoader implements LoggerAwareInterface {
 	 * @return string Sanitized text that can be returned to the user
 	 */
 	protected static function formatExceptionNoComment( Throwable $e ) {
-		$showExceptionDetails = MediaWikiServices::getInstance()->getMainConfig()->get(
-			MainConfigNames::ShowExceptionDetails );
-
-		if ( !$showExceptionDetails ) {
+		if ( !MWExceptionRenderer::shouldShowExceptionDetails() ) {
 			return MWExceptionHandler::getPublicLogMessage( $e );
 		}