diff --git a/bridges/FilterBridge.php b/bridges/FilterBridge.php
index ef739de3..1d920f90 100644
--- a/bridges/FilterBridge.php
+++ b/bridges/FilterBridge.php
@@ -73,6 +73,15 @@ class FilterBridge extends FeedExpander
         ],
     ]];
 
+    public function collectData()
+    {
+        $url = $this->getInput('url');
+        if (!Url::validate($url)) {
+            returnClientError('The url parameter must either refer to http or https protocol.');
+        }
+        $this->collectExpandableDatas($this->getURI());
+    }
+
     protected function parseItem($newItem)
     {
         $item = parent::parseItem($newItem);
@@ -158,13 +167,4 @@ class FilterBridge extends FeedExpander
 
         return $url;
     }
-
-    public function collectData()
-    {
-        if ($this->getInput('url') && substr($this->getInput('url'), 0, 4) !== 'http') {
-            // just in case someone finds a way to access local files by playing with the url
-            returnClientError('The url parameter must either refer to http or https protocol.');
-        }
-        $this->collectExpandableDatas($this->getURI());
-    }
 }
diff --git a/formats/AtomFormat.php b/formats/AtomFormat.php
index 1b9053fa..9886e4b7 100644
--- a/formats/AtomFormat.php
+++ b/formats/AtomFormat.php
@@ -14,8 +14,6 @@ class AtomFormat extends FormatAbstract
     protected const ATOM_NS = 'http://www.w3.org/2005/Atom';
     protected const MRSS_NS = 'http://search.yahoo.com/mrss/';
 
-    const LIMIT_TITLE = 140;
-
     public function stringify()
     {
         $feedUrl = get_current_url();
@@ -109,8 +107,8 @@ class AtomFormat extends FormatAbstract
 
             if (empty($entryTitle)) {
                 $entryTitle = str_replace("\n", ' ', strip_tags($entryContent));
-                if (strlen($entryTitle) > self::LIMIT_TITLE) {
-                    $wrapPos = strpos(wordwrap($entryTitle, self::LIMIT_TITLE), "\n");
+                if (strlen($entryTitle) > 140) {
+                    $wrapPos = strpos(wordwrap($entryTitle, 140), "\n");
                     $entryTitle = substr($entryTitle, 0, $wrapPos) . '...';
                 }
             }
@@ -182,11 +180,11 @@ class AtomFormat extends FormatAbstract
             }
         }
 
-        $toReturn = $document->saveXML();
+        $xml = $document->saveXML();
 
         // Remove invalid characters
         ini_set('mbstring.substitute_character', 'none');
-        $toReturn = mb_convert_encoding($toReturn, $this->getCharset(), 'UTF-8');
-        return $toReturn;
+        $xml = mb_convert_encoding($xml, $this->getCharset(), 'UTF-8');
+        return $xml;
     }
 }
diff --git a/formats/HtmlFormat.php b/formats/HtmlFormat.php
index 9ee4aeea..4933af8d 100644
--- a/formats/HtmlFormat.php
+++ b/formats/HtmlFormat.php
@@ -6,6 +6,8 @@ class HtmlFormat extends FormatAbstract
 
     public function stringify()
     {
+        $queryString = $_SERVER['QUERY_STRING'];
+
         $extraInfos = $this->getExtraInfos();
         $formatFactory = new FormatFactory();
         $buttons = [];
@@ -15,7 +17,7 @@ class HtmlFormat extends FormatAbstract
             if ($format === 'Html') {
                 continue;
             }
-            $formatUrl = '?' . str_ireplace('format=Html', 'format=' . $format, htmlentities($_SERVER['QUERY_STRING']));
+            $formatUrl = '?' . str_ireplace('format=Html', 'format=' . $format, htmlentities($queryString));
             $buttons[] = [
                 'href' => $formatUrl,
                 'value' => $format,
@@ -57,6 +59,7 @@ class HtmlFormat extends FormatAbstract
         ]);
         // Remove invalid characters
         ini_set('mbstring.substitute_character', 'none');
-        return mb_convert_encoding($html, $this->getCharset(), 'UTF-8');
+        $html = mb_convert_encoding($html, $this->getCharset(), 'UTF-8');
+        return $html;
     }
 }
diff --git a/formats/JsonFormat.php b/formats/JsonFormat.php
index 5bb1a525..dd61da41 100644
--- a/formats/JsonFormat.php
+++ b/formats/JsonFormat.php
@@ -110,13 +110,8 @@ class JsonFormat extends FormatAbstract
         }
         $data['items'] = $items;
 
-        /**
-         * The intention here is to discard non-utf8 byte sequences.
-         * But the JSON_PARTIAL_OUTPUT_ON_ERROR also discards lots of other errors.
-         * So consider this a hack.
-         * Switch to JSON_INVALID_UTF8_IGNORE when PHP 7.2 is the latest platform requirement.
-         */
-        $json = json_encode($data, \JSON_PRETTY_PRINT | \JSON_PARTIAL_OUTPUT_ON_ERROR);
+        // Ignoring invalid json
+        $json = json_encode($data, \JSON_PRETTY_PRINT | \JSON_INVALID_UTF8_IGNORE);
 
         return $json;
     }
diff --git a/formats/MrssFormat.php b/formats/MrssFormat.php
index 3c3dce5a..984611c7 100644
--- a/formats/MrssFormat.php
+++ b/formats/MrssFormat.php
@@ -32,12 +32,6 @@ class MrssFormat extends FormatAbstract
     protected const ATOM_NS = 'http://www.w3.org/2005/Atom';
     protected const MRSS_NS = 'http://search.yahoo.com/mrss/';
 
-    const ALLOWED_IMAGE_EXT = [
-        '.gif',
-        '.jpg',
-        '.png',
-    ];
-
     public function stringify()
     {
         $feedUrl = get_current_url();
@@ -72,8 +66,13 @@ class MrssFormat extends FormatAbstract
         $channel->appendChild($description);
         $description->appendChild($document->createTextNode($extraInfos['name']));
 
+        $allowedIconExtensions = [
+            '.gif',
+            '.jpg',
+            '.png',
+        ];
         $icon = $extraInfos['icon'];
-        if (!empty($icon) && in_array(substr($icon, -4), self::ALLOWED_IMAGE_EXT)) {
+        if (!empty($icon) && in_array(substr($icon, -4), $allowedIconExtensions)) {
             $feedImage = $document->createElement('image');
             $channel->appendChild($feedImage);
             $iconUrl = $document->createElement('url');
@@ -164,11 +163,10 @@ class MrssFormat extends FormatAbstract
             }
         }
 
-        $toReturn = $document->saveXML();
-
+        $xml = $document->saveXML();
         // Remove invalid non-UTF8 characters
         ini_set('mbstring.substitute_character', 'none');
-        $toReturn = mb_convert_encoding($toReturn, $this->getCharset(), 'UTF-8');
-        return $toReturn;
+        $xml = mb_convert_encoding($xml, $this->getCharset(), 'UTF-8');
+        return $xml;
     }
 }
diff --git a/formats/PlaintextFormat.php b/formats/PlaintextFormat.php
index c8c4e9d6..0a9237d0 100644
--- a/formats/PlaintextFormat.php
+++ b/formats/PlaintextFormat.php
@@ -6,18 +6,14 @@ class PlaintextFormat extends FormatAbstract
 
     public function stringify()
     {
-        $items = $this->getItems();
         $data = [];
-
-        foreach ($items as $item) {
+        foreach ($this->getItems() as $item) {
             $data[] = $item->toArray();
         }
-
-        $toReturn = print_r($data, true);
-
+        $text = print_r($data, true);
         // Remove invalid non-UTF8 characters
         ini_set('mbstring.substitute_character', 'none');
-        $toReturn = mb_convert_encoding($toReturn, $this->getCharset(), 'UTF-8');
-        return $toReturn;
+        $text = mb_convert_encoding($text, $this->getCharset(), 'UTF-8');
+        return $text;
     }
 }
diff --git a/formats/SfeedFormat.php b/formats/SfeedFormat.php
index 85d5f608..33740aaa 100644
--- a/formats/SfeedFormat.php
+++ b/formats/SfeedFormat.php
@@ -4,6 +4,38 @@ class SfeedFormat extends FormatAbstract
 {
     const MIME_TYPE = 'text/plain';
 
+    public function stringify()
+    {
+        $text = '';
+        foreach ($this->getItems() as $item) {
+            $text .= sprintf(
+                "%s\t%s\t%s\t%s\thtml\t\t%s\t%s\t%s\n",
+                $item->toArray()['timestamp'],
+                preg_replace('/\s/', ' ', $item->toArray()['title']),
+                $item->toArray()['uri'],
+                $this->escape($item->toArray()['content']),
+                $item->toArray()['author'],
+                $this->getFirstEnclosure(
+                    $item->toArray()['enclosures']
+                ),
+                $this->escape(
+                    $this->getCategories(
+                        $item->toArray()['categories']
+                    )
+                )
+            );
+        }
+
+        // Remove invalid non-UTF8 characters
+        ini_set('mbstring.substitute_character', 'none');
+        $text = mb_convert_encoding(
+            $text,
+            $this->getCharset(),
+            'UTF-8'
+        );
+        return $text;
+    }
+
     private function escape(string $str)
     {
         $str = str_replace('\\', '\\\\', $str);
@@ -31,39 +63,4 @@ class SfeedFormat extends FormatAbstract
         }
         return $toReturn;
     }
-
-    public function stringify()
-    {
-        $items = $this->getItems();
-
-        $toReturn = '';
-        foreach ($items as $item) {
-            $toReturn .= sprintf(
-                "%s\t%s\t%s\t%s\thtml\t\t%s\t%s\t%s\n",
-                $item->toArray()['timestamp'],
-                preg_replace('/\s/', ' ', $item->toArray()['title']),
-                $item->toArray()['uri'],
-                $this->escape($item->toArray()['content']),
-                $item->toArray()['author'],
-                $this->getFirstEnclosure(
-                    $item->toArray()['enclosures']
-                ),
-                $this->escape(
-                    $this->getCategories(
-                        $item->toArray()['categories']
-                    )
-                )
-            );
-        }
-
-        // Remove invalid non-UTF8 characters
-        ini_set('mbstring.substitute_character', 'none');
-        $toReturn = mb_convert_encoding(
-            $toReturn,
-            $this->getCharset(),
-            'UTF-8'
-        );
-        return $toReturn;
-    }
 }
-// vi: expandtab
diff --git a/lib/contents.php b/lib/contents.php
index e173b542..432d9139 100644
--- a/lib/contents.php
+++ b/lib/contents.php
@@ -15,6 +15,7 @@ function getContents(
     bool $returnFull = false
 ) {
     $httpClient = RssBridge::getHttpClient();
+    $cache = RssBridge::getCache();
 
     $httpHeadersNormalized = [];
     foreach ($httpHeaders as $httpHeader) {
@@ -51,7 +52,6 @@ function getContents(
         $config['proxy'] = Configuration::getConfig('proxy', 'url');
     }
 
-    $cache = RssBridge::getCache();
     $cacheKey = 'server_' . $url;
 
     /** @var Response $cachedResponse */
diff --git a/lib/logger.php b/lib/logger.php
index 5d95e673..e41de34b 100644
--- a/lib/logger.php
+++ b/lib/logger.php
@@ -148,7 +148,7 @@ final class StreamHandler
             $context
         );
         error_log($text);
-        if (Debug::isEnabled()) {
+        if ($record['level'] < Logger::ERROR && Debug::isEnabled()) {
             print sprintf("<pre>%s</pre>\n", e($text));
         }
         //$bytes = file_put_contents('/tmp/rss-bridge.log', $text, FILE_APPEND | LOCK_EX);
diff --git a/tests/FeedItemTest.php b/tests/FeedItemTest.php
new file mode 100644
index 00000000..92833753
--- /dev/null
+++ b/tests/FeedItemTest.php
@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace RssBridge\Tests;
+
+use FeedItem;
+use PHPUnit\Framework\TestCase;
+
+class FeedItemTest extends TestCase
+{
+    public function test()
+    {
+        $item = new FeedItem();
+        $item->setTitle('hello');
+        $this->assertSame('hello', $item->getTitle());
+
+        $item = FeedItem::fromArray(['title' => 'hello2']);
+        $this->assertSame('hello2', $item->getTitle());
+
+        $item = new FeedItem();
+        $item->setAuthor('123');
+        $this->assertSame('123', $item->getAuthor());
+
+        $item = new FeedItem();
+        $item->title = 'aa';
+        $this->assertSame('aa', $item->getTitle());
+        $this->assertSame('aa', $item->title);
+    }
+}