Regression tests

tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php

@@ -508,4 +508,14 @@ public function testSpecifyExistentOffsetWhenEnteringForeach(): void
 		$this->analyse([__DIR__ . '/data/specify-existent-offset-when-entering-foreach.php'], []);
 	}
 
+	public function testBug3872(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-3872.php'], []);
+	}
+
+	public function testBug6783(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-6783.php'], []);
+	}
+
 }

tests/PHPStan/Rules/Arrays/data/bug-3872.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Bug3872;
+
+class Demo
+{
+	public function analyze($json): void
+	{
+		foreach (json_decode($json, true) as $item) {
+			$item += ['value' => '', 'operator' => ''];
+			if ($item['value']) {
+				$item['value'] = strtotime($item['value']);
+				if ($item['operator'] === 'eq') {
+					echo 'test';
+				}
+			}
+		}
+	}
+}

tests/PHPStan/Rules/Arrays/data/bug-6783.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace Bug6783;
+
+/**
+ * @return array<string, mixed>
+ */
+function foo(): array
+{
+	// something from elsewhere (not in the scope of PHPStan)
+	return [
+		// removing or keeping those lines does/should not change the reporting
+		'foo' => [
+			'bar' => true,
+		]
+	];
+}
+
+function bar() {
+	$data = foo();
+	$data = $data['foo'] ?? []; // <<< removing this line suppress the error
+	$data += [
+		'default' => true,
+	];
+	foreach (['formatted'] as $field) {
+		$data[$field] = empty($data[$field]) ? false : true;
+	}
+
+	$bar = $data['bar'];
+}
+