Add more type checking to satisfy PHPStan and update some PHPStan exceptions

config/phpstan/phpstan.neon

@@ -13,6 +13,12 @@ parameters:
 
 		# Ignore errors caused by missing phpdoc strings for arrays
 		- '#Method .+? has parameter .+? with no value type specified in iterable type array.#'
+
+		# Ignore errors caused by type hints that should be union types. Union types are not yet supported in PHP.
+		- '#Function vd(s|d)?\(\) has parameter \$var with no typehint specified.#'
+		- '#Method Ebook::NullIfEmpty\(\) has parameter \$elements with no typehint specified.#'
+		- '#Method HttpInput::GetHttpVar\(\) has no return typehint specified.#'
+		- '#Method HttpInput::GetHttpVar\(\) has parameter \$default with no typehint specified.#'
 	level:
 		7
 	paths:

lib/OpdsFeed.php

@@ -1,6 +1,7 @@
 <?
 use function Safe\file_get_contents;
 use function Safe\file_put_contents;
+use function Safe\preg_replace;
 use function Safe\rename;
 use function Safe\tempnam;
 
@@ -22,14 +23,24 @@ class OpdsFeed{
 			$xml = new SimpleXMLElement(str_replace('xmlns=', 'ns=', $xmlString));
 			$xml->registerXPathNamespace('dc', 'http://purl.org/dc/elements/1.1/');
 			$xml->registerXPathNamespace('schema', 'http://schema.org/');
-			$entries = $xml->xpath('/feed/entry') ?? [];
+			$entries = $xml->xpath('/feed/entry');
+
+			if($entries === false){
+				$entries = [];
+			}
 
 			$output = '';
 			foreach($entries as $entry){
 				// Remove any <updated> elements, we don't want to compare against those.
 				// This makes it easier to for example generate a new subjects index,
 				// while updating it at the same time.
-				foreach($xml->xpath('/feed/entry/updated') as $element){
+				$elements = $xml->xpath('/feed/entry/updated');
+
+				if($elements === false){
+					$elements = [];
+				}
+
+				foreach($elements as $element){
 					unset($element[0]);
 				}
 
@@ -58,9 +69,21 @@ class OpdsFeed{
 			}
 			$xml = new SimpleXMLElement(str_replace('xmlns=', 'ns=', file_get_contents($parentFilepath)));
 
-			$feedEntry = ($xml->xpath('/feed/entry[id="' . $this->Id . '"]/updated') ?? [])[0];
-			$feedEntry[0] = $updatedTimestamp;
-			file_put_contents($parentFilepath, str_replace(" ns=", " xmlns=", $xml->asXml() ?? ''));
+			$feedEntries = $xml->xpath('/feed/entry[id="' . $this->Id . '"]/updated');
+			if($feedEntries === false){
+				$feedEntries = [];
+			}
+
+			if(sizeof($feedEntries) > 0){
+				$feedEntries[0][0] = $updatedTimestamp;
+			}
+
+			$xmlString = $xml->asXml();
+			if($xmlString === false){
+				$xmlString = '';
+			}
+
+			file_put_contents($parentFilepath, str_replace(" ns=", " xmlns=", $xmlString));
 
 			rename($tempFilename, $path);
 		}

scripts/generate-opds.php

@@ -4,6 +4,7 @@ require_once('/standardebooks.org/web/lib/Core.php');
 use function Safe\krsort;
 use function Safe\getopt;
 use function Safe\preg_replace;
+use function Safe\sort;
 
 $longopts = array("webroot:", "weburl:");
 $options = getopt("", $longopts);
@@ -51,8 +52,8 @@ $subjectsFeed->Save(WEB_ROOT . '/opds/subjects/index.xml');
 // Now generate each individual subject feed
 foreach($ebooksBySubject as $subject => $ebooks){
 	krsort($ebooks);
-	$subjectFeed = new OpdsAcquisitionFeed('/opds/subjects/' . Formatter::MakeUrlSafe($subject), $subject, '/opds/subjects', $ebooks);
-	$subjectFeed->Save(WEB_ROOT . '/opds/subjects/' . Formatter::MakeUrlSafe($subject) . '.xml');
+	$subjectFeed = new OpdsAcquisitionFeed('/opds/subjects/' . Formatter::MakeUrlSafe((string)$subject), (string)$subject, '/opds/subjects', $ebooks);
+	$subjectFeed->Save(WEB_ROOT . '/opds/subjects/' . Formatter::MakeUrlSafe((string)$subject) . '.xml');
 }
 
 // Create the 'all' feed