Fix for potential bug with non-backed enums (laravel#43842)

* Abstract enum case and value retrieval to methods, and fix potential bug with addCastAttributesToArray

* Make sure relation dictionaries support non-backed enums too

* Fix bug with leftover ::class

* Fix styling

* More styling fixes

* formatting

Co-authored-by: Taylor Otwell <[email protected]>

Author: ollieread

src/Illuminate/Database/Eloquent/Concerns/HasAttributes.php

@@ -2,6 +2,7 @@
 
 namespace Illuminate\Database\Eloquent\Concerns;
 
+use BackedEnum;
 use Carbon\CarbonImmutable;
 use Carbon\CarbonInterface;
 use DateTimeImmutable;
@@ -307,7 +308,7 @@ protected function addCastAttributesToArray(array $attributes, array $mutatedAtt
             }
 
             if ($this->isEnumCastable($key) && (! ($attributes[$key] ?? null) instanceof Arrayable)) {
-                $attributes[$key] = isset($attributes[$key]) ? $attributes[$key]->value : null;
+                $attributes[$key] = isset($attributes[$key]) ? $this->getStorableEnumValue($attributes[$key]) : null;
             }
 
             if ($attributes[$key] instanceof Arrayable) {
@@ -814,11 +815,7 @@ protected function getEnumCastableAttributeValue($key, $value)
             return $value;
         }
 
-        if (is_subclass_of($castType, \BackedEnum::class)) {
-            return $castType::from($value);
-        }
-
-        return constant($castType.'::'.$value);
+        return $this->getEnumCaseFromValue($castType, $value);
     }
 
     /**
@@ -1123,21 +1120,42 @@ protected function setEnumCastableAttribute($key, $value)
 
         if (! isset($value)) {
             $this->attributes[$key] = null;
-        } elseif (is_subclass_of($enumClass, \BackedEnum::class)) {
-            if ($value instanceof $enumClass) {
-                $this->attributes[$key] = $value->value;
-            } else {
-                $this->attributes[$key] = $enumClass::from($value)->value;
-            }
+        } elseif (is_object($value)) {
+            $this->attributes[$key] = $this->getStorableEnumValue($value);
         } else {
-            if ($value instanceof $enumClass) {
-                $this->attributes[$key] = $value->name;
-            } else {
-                $this->attributes[$key] = constant($enumClass.'::'.$value)->name;
-            }
+            $this->attributes[$key] = $this->getStorableEnumValue(
+                $this->getEnumCaseFromValue($enumClass, $value)
+            );
         }
     }
 
+    /**
+     * Get an enum case instance from a given class and value.
+     *
+     * @param  string  $enumClass
+     * @param  string|int  $value
+     * @return \UnitEnum|\BackedEnum
+     */
+    protected function getEnumCaseFromValue($enumClass, $value)
+    {
+        return is_subclass_of($enumClass, BackedEnum::class)
+                ? $enumClass::from($value)
+                : constant($enumClass.'::'.$value);
+    }
+
+    /**
+     * Get the storable value from the given enum.
+     *
+     * @param  \UnitEnum|\BackedEnum  $value
+     * @return string|int
+     */
+    protected function getStorableEnumValue($value)
+    {
+        return $value instanceof BackedEnum
+                ? $value->value
+                : $value->name;
+    }
+
     /**
      * Get an array attribute with the given key and value set.
      *

src/Illuminate/Database/Eloquent/Relations/Concerns/InteractsWithDictionary.php

@@ -4,6 +4,7 @@
 
 use BackedEnum;
 use Doctrine\Instantiator\Exception\InvalidArgumentException;
+use UnitEnum;
 
 trait InteractsWithDictionary
 {
@@ -23,8 +24,8 @@ protected function getDictionaryKey($attribute)
             }
 
             if (function_exists('enum_exists') &&
-                $attribute instanceof BackedEnum) {
-                return $attribute->value;
+                $attribute instanceof UnitEnum) {
+                return $attribute instanceof BackedEnum ? $attribute->value : $attribute->name;
             }
 
             throw new InvalidArgumentException('Model attribute value is an object but does not have a __toString method.');