diff --git a/app/Models/RuleAction.php b/app/Models/RuleAction.php
index f5cf1bfccf..1c1a96e3c3 100644
--- a/app/Models/RuleAction.php
+++ b/app/Models/RuleAction.php
@@ -69,12 +69,12 @@ class RuleAction extends Model
 
     protected $casts
                         = [
-            'created_at'      => 'datetime',
-            'updated_at'      => 'datetime',
-            'active'          => 'boolean',
-            'order'           => 'int',
-            'stop_processing' => 'boolean',
-        ];
+                            'created_at'      => 'datetime',
+                            'updated_at'      => 'datetime',
+                            'active'          => 'boolean',
+                            'order'           => 'int',
+                            'stop_processing' => 'boolean',
+                        ];
 
     protected $fillable = ['rule_id', 'action_type', 'action_value', 'order', 'active', 'stop_processing'];
 
diff --git a/app/TransactionRules/Actions/SetAmount.php b/app/TransactionRules/Actions/SetAmount.php
index 54501e6659..f7209ffe53 100644
--- a/app/TransactionRules/Actions/SetAmount.php
+++ b/app/TransactionRules/Actions/SetAmount.php
@@ -28,7 +28,6 @@ use FireflyIII\Events\TriggeredAuditLog;
 use FireflyIII\Models\RuleAction;
 use FireflyIII\Models\Transaction;
 use FireflyIII\Models\TransactionJournal;
-use FireflyIII\Support\Facades\Steam;
 use FireflyIII\TransactionRules\Traits\RefreshNotesTrait;
 
 class SetAmount implements ActionInterface
@@ -59,7 +58,7 @@ class SetAmount implements ActionInterface
 
         $value      = $this->action->getValue($journal);
 
-        if (!is_numeric($value) || '' === $value || 0 === bccomp((string)$value, '0')) {
+        if (!is_numeric($value) || 0 === bccomp($value, '0')) {
             app('log')->debug(sprintf('RuleAction SetAmount, amount "%s" is not a number or is zero, will not continue.', $value));
             event(new RuleActionFailedOnArray($this->action, $journal, trans('rules.journal_invalid_amount', ['amount' => $value])));
 
@@ -69,16 +68,14 @@ class SetAmount implements ActionInterface
         /** @var TransactionJournal $object */
         $object     = TransactionJournal::where('user_id', $journal['user_id'])->find($journal['transaction_journal_id']);
 
-        // doesn't actually do anything!
-        $positive   = Steam::positive($value);
-        $negative   = Steam::negative($value);
+        $positive   = app('steam')->positive($value);
+        $negative   = app('steam')->negative($value);
 
         $this->updatePositive($object, $positive);
         $this->updateNegative($object, $negative);
         $object->transactionGroup->touch();
 
         // event for audit log entry
-
         event(new TriggeredAuditLog(
             $this->action->rule,
             $object,
diff --git a/app/TransactionRules/Expressions/ActionExpressionLanguageProvider.php b/app/TransactionRules/Expressions/ActionExpressionLanguageProvider.php
index a608fc6848..f871b3390a 100644
--- a/app/TransactionRules/Expressions/ActionExpressionLanguageProvider.php
+++ b/app/TransactionRules/Expressions/ActionExpressionLanguageProvider.php
@@ -27,38 +27,35 @@ namespace FireflyIII\TransactionRules\Expressions;
 use Symfony\Component\ExpressionLanguage\ExpressionFunction;
 use Symfony\Component\ExpressionLanguage\ExpressionFunctionProviderInterface;
 
+/**
+ * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+ */
 class ActionExpressionLanguageProvider implements ExpressionFunctionProviderInterface
 {
     public function getFunctions(): array
     {
+        $function = function ($arguments, $str): string {
+            if (!is_string($str)) {
+                return (string) $str;
+            }
+
+            return strtolower($str.'!');
+        };
+
         return [
             new ExpressionFunction(
-                'constant',
-                function ($str): string {
+                'constant2',
+                static function ($str): string {
                     return sprintf('(is_string(%1$s) ? strtolower(%1$s) : %1$s)', $str.'!');
                 },
-                // @SuppressWarnings(PHPMD.UnusedFormalParameter)
-                function ($arguments, $str): string {
-                    if (!is_string($str)) {
-                        return (string) $str;
-                    }
-
-                    return strtolower($str.'!');
-                }
+                $function
             ),
             new ExpressionFunction(
-                'enum',
-                function ($str): string {
-                    return sprintf('(is_string(%1$s) ? strtolower(%1$s) : %1$s)', $str.'?');
+                'constant',
+                static function ($str): string {
+                    return sprintf('(is_string(%1$s) ? strtolower(%1$s) : %1$s)', $str.'!');
                 },
-                // @SuppressWarnings(PHPMD.UnusedFormalParameter)
-                function ($arguments, $str): string {
-                    if (!is_string($str)) {
-                        return (string) $str;
-                    }
-
-                    return strtolower($str).'?';
-                }
+                $function
             ),
 
             ExpressionFunction::fromPhp('substr'),
diff --git a/app/Transformers/V2/AccountTransformer.php b/app/Transformers/V2/AccountTransformer.php
index 4e0fb1e6c0..aef4ba7fe8 100644
--- a/app/Transformers/V2/AccountTransformer.php
+++ b/app/Transformers/V2/AccountTransformer.php
@@ -90,8 +90,9 @@ class AccountTransformer extends AbstractTransformer
         }
 
         // TODO needs separate method.
+        /** @var null|array $sort */
         $sort                    = $this->parameters->get('sort');
-        if (is_countable($sort) && count($sort) > 0) {
+        if (null !== $sort && count($sort) > 0) {
             foreach ($sort as $column => $direction) {
                 // account_number + iban
                 if ('iban' === $column) {