feat: implement automatic value casting in BaseFormRequest for improved validation

Author: aspirantzhang

app/Http/Requests/BaseFormRequest.php

@@ -12,6 +12,7 @@ protected function prepareForValidation()
     {
         parent::prepareForValidation();
         $this->route('id') && $this->merge(['id' => $this->route('id')]);
+        $this->autoCast();
     }
 
     protected function idRule(): array
@@ -20,4 +21,68 @@ protected function idRule(): array
             'id' => ['required', 'integer', 'gt:0'],
         ];
     }
+
+    private function autoCast(): void
+    {
+        $casts = $this->inferCastsFromRules();
+
+        $this->merge(
+            collect($this->all())
+                ->mapWithKeys(fn ($value, $key) => [
+                    $key => $this->castValue(
+                        $key,
+                        $value,
+                        $casts[$key] ?? null
+                    ),
+                ])
+                ->toArray()
+        );
+    }
+
+    private function inferCastsFromRules(): array
+    {
+        return collect($this->rules())
+            ->mapWithKeys(fn ($rules, $key) => [
+                $key => $this->parseTypeFromRules((array) $rules),
+            ])
+            ->filter()
+            ->toArray();
+    }
+
+    private function parseTypeFromRules(array $rules): ?string
+    {
+        foreach ($rules as $rule) {
+            if ($type = $this->matchPrimitiveType($rule)) {
+                return $type;
+            }
+        }
+
+        return null;
+    }
+
+    private function matchPrimitiveType($rule): ?string
+    {
+        return match (true) {
+            $rule === 'integer' => 'int',
+            $rule === 'boolean' => 'bool',
+            $rule === 'numeric' => 'float',
+            $rule === 'array' => 'array',
+            default => null
+        };
+    }
+
+    private function castValue(string $key, mixed $value, ?string $type): mixed
+    {
+        if ($type === null || $value === null) {
+            return $value;
+        }
+
+        return match ($type) {
+            'int' => (int) $value,
+            'float' => (float) $value,
+            'bool' => filter_var($value, FILTER_VALIDATE_BOOLEAN),
+            'array' => (array) $value,
+            default => $value
+        };
+    }
 }