diff --git a/lib/PhpParser/BuilderHelpers.php b/lib/PhpParser/BuilderHelpers.php
index 1a26dab..f5bfae9 100644
--- a/lib/PhpParser/BuilderHelpers.php
+++ b/lib/PhpParser/BuilderHelpers.php
@@ -27,7 +27,9 @@ final class BuilderHelpers
     public static function normalizeNode($node) : Node {
         if ($node instanceof Builder) {
             return $node->getNode();
-        } elseif ($node instanceof Node) {
+        }
+
+        if ($node instanceof Node) {
             return $node;
         }
 
@@ -127,18 +129,22 @@ final class BuilderHelpers
     private static function normalizeNameCommon($name, bool $allowExpr) {
         if ($name instanceof Name) {
             return $name;
-        } elseif (is_string($name)) {
+        }
+
+        if (is_string($name)) {
             if (!$name) {
                 throw new \LogicException('Name cannot be empty');
             }
 
             if ($name[0] === '\\') {
                 return new Name\FullyQualified(substr($name, 1));
-            } elseif (0 === strpos($name, 'namespace\\')) {
-                return new Name\Relative(substr($name, strlen('namespace\\')));
-            } else {
-                return new Name($name);
             }
+
+            if (0 === strpos($name, 'namespace\\')) {
+                return new Name\Relative(substr($name, strlen('namespace\\')));
+            }
+
+            return new Name($name);
         }
 
         if ($allowExpr) {
@@ -148,9 +154,9 @@ final class BuilderHelpers
             throw new \LogicException(
                 'Name must be a string or an instance of Node\Name or Node\Expr'
             );
-        } else {
-            throw new \LogicException('Name must be a string or an instance of Node\Name');
         }
+
+        throw new \LogicException('Name must be a string or an instance of Node\Name');
     }
 
     /**
@@ -215,21 +221,33 @@ final class BuilderHelpers
     public static function normalizeValue($value) : Expr {
         if ($value instanceof Node\Expr) {
             return $value;
-        } elseif (is_null($value)) {
+        }
+
+        if (is_null($value)) {
             return new Expr\ConstFetch(
                 new Name('null')
             );
-        } elseif (is_bool($value)) {
+        }
+
+        if (is_bool($value)) {
             return new Expr\ConstFetch(
                 new Name($value ? 'true' : 'false')
             );
-        } elseif (is_int($value)) {
+        }
+
+        if (is_int($value)) {
             return new Scalar\LNumber($value);
-        } elseif (is_float($value)) {
+        }
+
+        if (is_float($value)) {
             return new Scalar\DNumber($value);
-        } elseif (is_string($value)) {
+        }
+
+        if (is_string($value)) {
             return new Scalar\String_($value);
-        } elseif (is_array($value)) {
+        }
+
+        if (is_array($value)) {
             $items = [];
             $lastKey = -1;
             foreach ($value as $itemKey => $itemValue) {
@@ -248,9 +266,9 @@ final class BuilderHelpers
             }
 
             return new Expr\Array_($items);
-        } else {
-            throw new \LogicException('Invalid value');
         }
+
+        throw new \LogicException('Invalid value');
     }
 
     /**
@@ -263,11 +281,13 @@ final class BuilderHelpers
     public static function normalizeDocComment($docComment) : Comment\Doc {
         if ($docComment instanceof Comment\Doc) {
             return $docComment;
-        } elseif (is_string($docComment)) {
-            return new Comment\Doc($docComment);
-        } else {
-            throw new \LogicException('Doc comment must be a string or an instance of PhpParser\Comment\Doc');
         }
+
+        if (is_string($docComment)) {
+            return new Comment\Doc($docComment);
+        }
+
+        throw new \LogicException('Doc comment must be a string or an instance of PhpParser\Comment\Doc');
     }
 
     /**
diff --git a/test/PhpParser/BuilderHelpersTest.php b/test/PhpParser/BuilderHelpersTest.php
index 72f2b84..9376cda 100644
--- a/test/PhpParser/BuilderHelpersTest.php
+++ b/test/PhpParser/BuilderHelpersTest.php
@@ -2,15 +2,205 @@
 
 namespace PhpParser;
 
-use PhpParser\Node\Attribute;
-use PhpParser\Node\AttributeGroup;
-use PhpParser\Node\Name;
+use PhpParser\Builder\Class_;
+use PhpParser\Node\Scalar;
+use PhpParser\Node\Stmt;
+use PhpParser\Node\Expr;
 
 class BuilderHelpersTest extends \PHPUnit\Framework\TestCase
 {
+    public function testNormalizeNode() {
+        $builder = new Class_('SomeClass');
+        $this->assertEquals($builder->getNode(), BuilderHelpers::normalizeNode($builder));
+
+        $attribute = new Node\Attribute(new Node\Name('Test'));
+        $this->assertSame($attribute, BuilderHelpers::normalizeNode($attribute));
+
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Expected node or builder object');
+        BuilderHelpers::normalizeNode('test');
+    }
+
+    public function testNormalizeStmt() {
+        $stmt = new Node\Stmt\Class_('Class');
+        $this->assertSame($stmt, BuilderHelpers::normalizeStmt($stmt));
+
+        $expr = new Expr\Variable('fn');
+        $normalizedExpr = BuilderHelpers::normalizeStmt($expr);
+        $this->assertEquals(new Stmt\Expression($expr), $normalizedExpr);
+        $this->assertSame($expr, $normalizedExpr->expr);
+
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Expected statement or expression node');
+        BuilderHelpers::normalizeStmt(new Node\Attribute(new Node\Name('Test')));
+    }
+
+    public function testNormalizeStmtInvalidType() {
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Expected node or builder object');
+        BuilderHelpers::normalizeStmt('test');
+    }
+
+    public function testNormalizeIdentifier() {
+        $identifier = new Node\Identifier('fn');
+        $this->assertSame($identifier, BuilderHelpers::normalizeIdentifier($identifier));
+        $this->assertEquals($identifier, BuilderHelpers::normalizeIdentifier('fn'));
+
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Expected string or instance of Node\Identifier');
+        BuilderHelpers::normalizeIdentifier(1);
+    }
+
+    public function testNormalizeIdentifierOrExpr() {
+        $identifier = new Node\Identifier('fn');
+        $this->assertSame($identifier, BuilderHelpers::normalizeIdentifierOrExpr($identifier));
+
+        $expr = new Expr\Variable('fn');
+        $this->assertSame($expr, BuilderHelpers::normalizeIdentifierOrExpr($expr));
+        $this->assertEquals($identifier, BuilderHelpers::normalizeIdentifierOrExpr('fn'));
+
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Expected string or instance of Node\Identifier');
+        BuilderHelpers::normalizeIdentifierOrExpr(1);
+    }
+
+    public function testNormalizeName() {
+        $name = new Node\Name('test');
+        $this->assertSame($name, BuilderHelpers::normalizeName($name));
+        $this->assertEquals(
+            new Node\Name\FullyQualified(['Namespace', 'Test']),
+            BuilderHelpers::normalizeName('\\Namespace\\Test')
+        );
+        $this->assertEquals(
+            new Node\Name\Relative(['Test']),
+            BuilderHelpers::normalizeName('namespace\\Test')
+        );
+        $this->assertEquals($name, BuilderHelpers::normalizeName('test'));
+
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Name cannot be empty');
+        BuilderHelpers::normalizeName('');
+    }
+
+    public function testNormalizeNameInvalidType() {
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Name must be a string or an instance of Node\Name');
+        BuilderHelpers::normalizeName(1);
+    }
+
+    public function testNormalizeNameOrExpr() {
+        $expr = new Expr\Variable('fn');
+        $this->assertSame($expr, BuilderHelpers::normalizeNameOrExpr($expr));
+
+        $name = new Node\Name('test');
+        $this->assertSame($name, BuilderHelpers::normalizeNameOrExpr($name));
+        $this->assertEquals(
+            new Node\Name\FullyQualified(['Namespace', 'Test']),
+            BuilderHelpers::normalizeNameOrExpr('\\Namespace\\Test')
+        );
+        $this->assertEquals(
+            new Node\Name\Relative(['Test']),
+            BuilderHelpers::normalizeNameOrExpr('namespace\\Test')
+        );
+        $this->assertEquals($name, BuilderHelpers::normalizeNameOrExpr('test'));
+
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Name cannot be empty');
+        BuilderHelpers::normalizeNameOrExpr('');
+    }
+
+    public function testNormalizeNameOrExpInvalidType() {
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Name must be a string or an instance of Node\Name or Node\Expr');
+        BuilderHelpers::normalizeNameOrExpr(1);
+    }
+
+    public function testNormalizeType() {
+        $this->assertEquals(new Node\Identifier('array'), BuilderHelpers::normalizeType('array'));
+        $this->assertEquals(new Node\Identifier('callable'), BuilderHelpers::normalizeType('callable'));
+        $this->assertEquals(new Node\Identifier('string'), BuilderHelpers::normalizeType('string'));
+        $this->assertEquals(new Node\Identifier('int'), BuilderHelpers::normalizeType('int'));
+        $this->assertEquals(new Node\Identifier('float'), BuilderHelpers::normalizeType('float'));
+        $this->assertEquals(new Node\Identifier('bool'), BuilderHelpers::normalizeType('bool'));
+        $this->assertEquals(new Node\Identifier('iterable'), BuilderHelpers::normalizeType('iterable'));
+        $this->assertEquals(new Node\Identifier('void'), BuilderHelpers::normalizeType('void'));
+        $this->assertEquals(new Node\Identifier('object'), BuilderHelpers::normalizeType('object'));
+        $this->assertEquals(new Node\Identifier('mixed'), BuilderHelpers::normalizeType('mixed'));
+
+        $intIdentifier = new Node\Identifier('int');
+        $this->assertSame($intIdentifier, BuilderHelpers::normalizeType($intIdentifier));
+
+        $intName = new Node\Name('int');
+        $this->assertSame($intName, BuilderHelpers::normalizeType($intName));
+
+        $intNullable = new Node\NullableType('int');
+        $this->assertSame($intNullable, BuilderHelpers::normalizeType($intNullable));
+
+        $unionType = new Node\UnionType([new Node\Identifier('int'), new Node\Identifier('string')]);
+        $this->assertSame($unionType, BuilderHelpers::normalizeType($unionType));
+
+        $expectedNullable = new Node\NullableType($intIdentifier);
+        $nullable = BuilderHelpers::normalizeType('?int');
+        $this->assertEquals($expectedNullable, $nullable);
+        $this->assertEquals($intIdentifier, $nullable->type);
+
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Type must be a string, or an instance of Name, Identifier, NullableType or UnionType');
+        BuilderHelpers::normalizeType(1);
+    }
+
+    public function testNormalizeTypeNullableVoid() {
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('void type cannot be nullable');
+        BuilderHelpers::normalizeType('?void');
+    }
+
+    public function testNormalizeTypeNullableMixed() {
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('mixed type cannot be nullable');
+        BuilderHelpers::normalizeType('?mixed');
+    }
+
+    public function testNormalizeValue() {
+        $expression = new Scalar\LNumber(1);
+        $this->assertSame($expression, BuilderHelpers::normalizeValue($expression));
+
+        $this->assertEquals(new Expr\ConstFetch(new Node\Name('null')), BuilderHelpers::normalizeValue(null));
+        $this->assertEquals(new Expr\ConstFetch(new Node\Name('true')), BuilderHelpers::normalizeValue(true));
+        $this->assertEquals(new Expr\ConstFetch(new Node\Name('false')), BuilderHelpers::normalizeValue(false));
+        $this->assertEquals(new Scalar\LNumber(2), BuilderHelpers::normalizeValue(2));
+        $this->assertEquals(new Scalar\DNumber(2.5), BuilderHelpers::normalizeValue(2.5));
+        $this->assertEquals(new Scalar\String_('text'), BuilderHelpers::normalizeValue('text'));
+        $this->assertEquals(
+            new Expr\Array_([
+                new Expr\ArrayItem(new Scalar\LNumber(0)),
+                new Expr\ArrayItem(new Scalar\LNumber(1), new Scalar\String_('test')),
+            ]),
+            BuilderHelpers::normalizeValue([
+                0,
+                'test' => 1,
+            ])
+        );
+
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Invalid value');
+        BuilderHelpers::normalizeValue(new \stdClass());
+    }
+
+    public function testNormalizeDocComment() {
+        $docComment = new Comment\Doc('Some doc comment');
+        $this->assertSame($docComment, BuilderHelpers::normalizeDocComment($docComment));
+
+        $this->assertEquals($docComment, BuilderHelpers::normalizeDocComment('Some doc comment'));
+
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Doc comment must be a string or an instance of PhpParser\Comment\Doc');
+        BuilderHelpers::normalizeDocComment(1);
+    }
+
     public function testNormalizeAttribute() {
-        $attribute = new Attribute(new Name('Test'));
-        $attributeGroup = new AttributeGroup([$attribute]);
+        $attribute = new Node\Attribute(new Node\Name('Test'));
+        $attributeGroup = new Node\AttributeGroup([$attribute]);
 
         $this->assertEquals($attributeGroup, BuilderHelpers::normalizeAttribute($attribute));
         $this->assertSame($attributeGroup, BuilderHelpers::normalizeAttribute($attributeGroup));