Fix allow zero as expression value.

src/phpDocumentor/Reflection/Php/Expression.php

@@ -87,7 +87,7 @@ public static function generatePlaceholder(string $name): string
     /** @param array<string, Fqsen|Type> $parts */
     public function __construct(string $expression, array $parts = [])
     {
-        Assert::notEmpty($expression);
+        Assert::stringNotEmpty($expression);
         Assert::allIsInstanceOfAny($parts, [Fqsen::class, Type::class]);
 
         $this->expression = $expression;

tests/integration/EnumTest.php

@@ -61,7 +61,7 @@ public function testEnumWithConstant(): void
 
         $enum = $file->getEnums()['\MyNamespace\MyEnumWithConstant'];
         self::assertInstanceOf(Enum_::class, $enum);
-        self::assertCount(1, $enum->getConstants());
+        self::assertCount(2, $enum->getConstants());
         self::assertArrayHasKey('\MyNamespace\MyEnumWithConstant::MYCONST', $enum->getConstants());
         self::assertSame("'MyConstValue'", $enum->getConstants()['\MyNamespace\MyEnumWithConstant::MYCONST']->getValue());
     }

tests/integration/data/Enums/enumWithConstant.php

@@ -7,4 +7,6 @@
 enum MyEnumWithConstant
 {
     public const MYCONST = 'MyConstValue';
+
+    public const INT_CONST = 0;
 }

tests/unit/phpDocumentor/Reflection/Php/ExpressionTest.php

@@ -13,9 +13,11 @@
 
 namespace phpDocumentor\Reflection\Php;
 
+use Generator;
 use InvalidArgumentException;
 use phpDocumentor\Reflection\Fqsen;
 use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
 
 use function sprintf;
@@ -110,4 +112,21 @@ public function testOverridePartsWhenRenderingExpression(): void
 
         self::assertSame(sprintf('This is an %s expression', $replacement), $result);
     }
+
+    #[DataProvider('expressionValues')]
+    public function testExpressionTemplateCreation(string $expression): void
+    {
+        $actual = new Expression($expression, []);
+        self::assertSame($expression, $actual->getExpression());
+    }
+
+    /** @return Generator<string, array{expression: string} */
+    public static function expressionValues(): Generator
+    {
+        $values = ['0', 'null', 'false'];
+
+        foreach ($values as $value) {
+            yield $value => ['expression' => $value];
+        }
+    }
 }