Patch foreach for mullable values guarded by ifs

Enno Woortmann · Enno Woortmann · commit 8a885773679a · 2026-03-01T22:31:09.000+01:00
diff --git a/src/Render.php b/src/Render.php
@@ -131,7 +131,18 @@ protected function resolveLoops(string $template, array $variables): string
             '/\{%\s*foreach(?<index>-[\d]+-[\d]+-)\s+' . self::REGEX_VARIABLE . '\s+as\s+((?<key>\w+)\s*,\s*)?(?<value>\w+)\s*%\}' .
                 '(?<body>.+)' .
             '\{%\s*endforeach\k<index>\s*%\}/si',
-            function (array $matches) use ($variables): string {
+            function (array $matches) use ($variables, $template): string {
+                // If this foreach is preceded by an unclosed {% if %} open tag in the template, it is nested inside a
+                // conditional that hasn't been evaluated yet. Return the original match unchanged so that
+                // resolveConditionals can strip the enclosing if-branch first, then call resolveLoops on the result.
+                $foreachPos = strpos($template, $matches[0]);
+                $prefix = substr($template, 0, $foreachPos);
+                $openIfCount = preg_match_all('/\{%\s*if-[\d]+-[\d]+-/i', $prefix);
+                $closeIfCount = preg_match_all('/\{%\s*endif-[\d]+-[\d]+-/i', $prefix);
+                if ($openIfCount > $closeIfCount) {
+                    return $matches[0];
+                }
+
                 $output = '';
 
                 foreach ($this->getValue($matches, $variables) as $key => $value) {
@@ -196,11 +207,9 @@ function (array $matches) use ($variables): string {
                         $orBranches[] = $andBranchTrue;
                     }
 
-                    if (in_array(true, $orBranches)) {
-                        return $conditionalBody[0];
-                    }
+                    $branch = in_array(true, $orBranches) ? $conditionalBody[0] : ($conditionalBody[1] ?? '');
 
-                    return $conditionalBody[1] ?? '';
+                    return $this->resolveLoops($branch, $variables);
                 },
                 $template,
                 -1,
diff --git a/tests/RenderTest.php b/tests/RenderTest.php
@@ -417,6 +417,83 @@ public function testNotCallableMethod(): void
         $this->render->renderTemplateString("{{ unknownMethod('abc') }}");
     }
 
+    /**
+     * A {% foreach %} whose iterable is a method call on a nullable variable must not be evaluated when
+     * it is wrapped in a falsy {% if %} guard — previously the foreach iterable was resolved before the
+     * enclosing if, causing a fatal "Trying to call ... on non-object" error.
+     */
+    public function testForeachInsideFalsyIfIsNotEvaluated(): void
+    {
+        $template = '{% if items %}{% foreach items.getCategories() as cat %}{{ cat }}{% endforeach %}{% endif %}';
+
+        $this->assertSame(
+            '',
+            $this->render->renderTemplateString($template, ['items' => null]),
+        );
+    }
+
+    /**
+     * When the {% if %} guard is truthy the {% foreach %} inside must still execute normally.
+     */
+    public function testForeachInsideTruthyIfIsEvaluated(): void
+    {
+        $template = '{% if items %}{% foreach items.getCategories() as cat %}{{ cat }},{% endforeach %}{% endif %}';
+
+        $this->assertSame(
+            'Oak,Birch,',
+            $this->render->renderTemplateString(
+                $template,
+                ['items' => new Product('Wood', true, ['Oak', 'Birch'])],
+            ),
+        );
+    }
+
+    /**
+     * A {% if %} inside a {% foreach %} that uses the loop variable in its condition must still work
+     * correctly — the loop variable must be in scope when the conditional is evaluated.
+     */
+    public function testIfInsideForeachCanUseLoopVariable(): void
+    {
+        $template = '{% foreach items as item %}{% if item.isVisible() %}{{ item.getTitle() }}{% endif %}{% endforeach %}';
+
+        $products = [
+            new Product('Hammer', true),
+            new Product('Nails', false),
+            new Product('Wood', true),
+        ];
+
+        $this->assertSame(
+            'HammerWood',
+            $this->render->renderTemplateString($template, ['items' => $products]),
+        );
+    }
+
+    /**
+     * A {% foreach %} inside the true-branch of a top-level {% if %}, and a sibling {% foreach %} outside
+     * any conditional, must both resolve correctly in a single template.
+     */
+    public function testForeachInsideIfAlongsideSiblingForeach(): void
+    {
+        $template =
+            '{% if extra %}{% foreach extra.getCategories() as cat %}[{{ cat }}]{% endforeach %}{% endif %}' .
+            '{% foreach items as item %}{{ item.getTitle() }}{% endforeach %}';
+
+        $products = [new Product('Hammer', true), new Product('Wood', true)];
+
+        $this->assertSame(
+            'HammerWood',
+            $this->render->renderTemplateString($template, ['items' => $products, 'extra' => null]),
+        );
+
+        $this->assertSame(
+            '[Oak][Birch]HammerWood',
+            $this->render->renderTemplateString(
+                $template,
+                ['items' => $products, 'extra' => new Product('Extra', true, ['Oak', 'Birch'])],
+            ),
+        );
+    }
+
     public function propertyDataProvider(): array
     {
         return [
