[12.x] Add enum() method to Config Repository

Author: pataar

src/Illuminate/Config/Repository.php

@@ -3,6 +3,7 @@
 namespace Illuminate\Config;
 
 use ArrayAccess;
+use BackedEnum;
 use Illuminate\Contracts\Config\Repository as ConfigContract;
 use Illuminate\Support\Arr;
 use Illuminate\Support\Collection;
@@ -200,6 +201,43 @@ public function collection(string $key, $default = null): Collection
         return new Collection($this->array($key, $default));
     }
 
+    /**
+     * Get the specified configuration value as an enum.
+     *
+     * @template TEnum of \BackedEnum
+     *
+     * @param  string  $key
+     * @param  class-string<TEnum>  $enumClass
+     * @param  (\Closure():(TEnum|null))|TEnum|null  $default
+     * @return TEnum
+     *
+     * @throws \InvalidArgumentException
+     */
+    public function enum(string $key, string $enumClass, $default = null): BackedEnum
+    {
+        $value = $this->get($key, $default);
+
+        if ($value instanceof $enumClass) {
+            return $value;
+        }
+
+        if ($value === null || ! enum_exists($enumClass) || ! is_subclass_of($enumClass, BackedEnum::class)) {
+            throw new InvalidArgumentException(
+                sprintf('Configuration value for key [%s] must be a valid backed enum value, %s given.', $key, gettype($value))
+            );
+        }
+
+        $enumValue = $enumClass::tryFrom($value);
+
+        if ($enumValue === null) {
+            throw new InvalidArgumentException(
+                sprintf('Configuration value for key [%s] is not a valid value for enum [%s].', $key, $enumClass)
+            );
+        }
+
+        return $enumValue;
+    }
+
     /**
      * Set a given configuration value.
      *

tests/Config/RepositoryTest.php

@@ -7,6 +7,18 @@
 use InvalidArgumentException;
 use PHPUnit\Framework\TestCase;
 
+enum TestStringBackedEnum: string
+{
+    case Foo = 'foo';
+    case Bar = 'bar';
+}
+
+enum TestIntBackedEnum: int
+{
+    case One = 1;
+    case Two = 2;
+}
+
 class RepositoryTest extends TestCase
 {
     /**
@@ -372,4 +384,60 @@ public function testItThrowsAnExceptionWhenTryingToGetNonFloatValueAsFloat(): vo
 
         $this->repository->float('a.b');
     }
+
+    public function testItGetsAsEnumFromStringValue(): void
+    {
+        $this->repository->set('string_enum', 'foo');
+
+        $this->assertSame(
+            TestStringBackedEnum::Foo,
+            $this->repository->enum('string_enum', TestStringBackedEnum::class)
+        );
+    }
+
+    public function testItGetsAsEnumFromIntValue(): void
+    {
+        $this->repository->set('int_enum', 1);
+
+        $this->assertSame(
+            TestIntBackedEnum::One,
+            $this->repository->enum('int_enum', TestIntBackedEnum::class)
+        );
+    }
+
+    public function testItGetsAsEnumWhenValueIsAlreadyEnumInstance(): void
+    {
+        $this->repository->set('enum_instance', TestStringBackedEnum::Bar);
+
+        $this->assertSame(
+            TestStringBackedEnum::Bar,
+            $this->repository->enum('enum_instance', TestStringBackedEnum::class)
+        );
+    }
+
+    public function testItGetsAsEnumWithDefault(): void
+    {
+        $this->assertSame(
+            TestStringBackedEnum::Foo,
+            $this->repository->enum('non_existent_key', TestStringBackedEnum::class, TestStringBackedEnum::Foo)
+        );
+    }
+
+    public function testItThrowsAnExceptionWhenEnumValueIsInvalid(): void
+    {
+        $this->repository->set('invalid_enum', 'invalid');
+
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('Configuration value for key [invalid_enum] is not a valid value for enum');
+
+        $this->repository->enum('invalid_enum', TestStringBackedEnum::class);
+    }
+
+    public function testItThrowsAnExceptionWhenEnumValueIsNull(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+        $this->expectExceptionMessage('Configuration value for key [non_existent] must be a valid backed enum value');
+
+        $this->repository->enum('non_existent', TestStringBackedEnum::class);
+    }
 }