diff --git a/tests/Core/File/GetDeclarationNameJSTest.js b/tests/Core/File/GetDeclarationNameJSTest.js
new file mode 100644
index 0000000000..ee0a76a44f
--- /dev/null
+++ b/tests/Core/File/GetDeclarationNameJSTest.js
@@ -0,0 +1,23 @@
+/* testInvalidTokenPassed */
+print something;
+
+var object =
+{
+    /* testClosure */
+    propertyName: function ()  {}
+}
+
+/* testFunction */
+function functionName() {}
+
+/* testClass */
+class ClassName
+{
+    /* testMethod */
+    methodName() {
+       return false;
+    }
+}
+
+/* testFunctionUnicode */
+function π() {}
diff --git a/tests/Core/File/GetDeclarationNameJSTest.php b/tests/Core/File/GetDeclarationNameJSTest.php
new file mode 100644
index 0000000000..a2b8968583
--- /dev/null
+++ b/tests/Core/File/GetDeclarationNameJSTest.php
@@ -0,0 +1,158 @@
+<?php
+/**
+ * Tests for the \PHP_CodeSniffer\Files\File::getDeclarationName method.
+ *
+ * @author    Juliette Reinders Folmer <phpcs_nospam@adviesenzo.nl>
+ * @copyright 2022-2024 PHPCSStandards Contributors
+ * @license   https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
+ */
+
+namespace PHP_CodeSniffer\Tests\Core\File;
+
+use PHP_CodeSniffer\Tests\Core\AbstractMethodUnitTest;
+
+/**
+ * Tests for the \PHP_CodeSniffer\Files\File:getDeclarationName method.
+ *
+ * @covers \PHP_CodeSniffer\Files\File::getDeclarationName
+ */
+class GetDeclarationNameJSTest extends AbstractMethodUnitTest
+{
+
+    /**
+     * The file extension of the test case file (without leading dot).
+     *
+     * @var string
+     */
+    protected static $fileExtension = 'js';
+
+
+    /**
+     * Test receiving an expected exception when a non-supported token is passed.
+     *
+     * @return void
+     */
+    public function testInvalidTokenPassed()
+    {
+        $this->expectRunTimeException('Token type "T_STRING" is not T_FUNCTION, T_CLASS, T_INTERFACE, T_TRAIT or T_ENUM');
+
+        $target = $this->getTargetToken('/* testInvalidTokenPassed */', T_STRING);
+        self::$phpcsFile->getDeclarationName($target);
+
+    }//end testInvalidTokenPassed()
+
+
+    /**
+     * Test receiving "null" when passed an anonymous construct or in case of a parse error.
+     *
+     * @param string     $testMarker The comment which prefaces the target token in the test file.
+     * @param int|string $targetType Token type of the token to get as stackPtr.
+     *
+     * @dataProvider dataGetDeclarationNameNull
+     *
+     * @return void
+     */
+    public function testGetDeclarationNameNull($testMarker, $targetType)
+    {
+        $target = $this->getTargetToken($testMarker, $targetType);
+        $result = self::$phpcsFile->getDeclarationName($target);
+        $this->assertNull($result);
+
+    }//end testGetDeclarationNameNull()
+
+
+    /**
+     * Data provider.
+     *
+     * @see GetDeclarationNameTest::testGetDeclarationNameNull()
+     *
+     * @return array<string, array<string, int|string>>
+     */
+    public static function dataGetDeclarationNameNull()
+    {
+        return [
+            'closure' => [
+                'testMarker' => '/* testClosure */',
+                'targetType' => T_CLOSURE,
+            ],
+        ];
+
+    }//end dataGetDeclarationNameNull()
+
+
+    /**
+     * Test retrieving the name of a function or OO structure.
+     *
+     * @param string                 $testMarker The comment which prefaces the target token in the test file.
+     * @param string                 $expected   Expected function output.
+     * @param array<int|string>|null $targetType Token type of the token to get as stackPtr.
+     *
+     * @dataProvider dataGetDeclarationName
+     *
+     * @return void
+     */
+    public function testGetDeclarationName($testMarker, $expected, $targetType=null)
+    {
+        if (isset($targetType) === false) {
+            $targetType = [
+                T_CLASS,
+                T_INTERFACE,
+                T_TRAIT,
+                T_ENUM,
+                T_FUNCTION,
+            ];
+        }
+
+        $target = $this->getTargetToken($testMarker, $targetType);
+        $result = self::$phpcsFile->getDeclarationName($target);
+        $this->assertSame($expected, $result);
+
+    }//end testGetDeclarationName()
+
+
+    /**
+     * Data provider.
+     *
+     * @see GetDeclarationNameTest::testGetDeclarationName()
+     *
+     * @return array<string, array<string, string|array<int|string>>>
+     */
+    public static function dataGetDeclarationName()
+    {
+        return [
+            'function'              => [
+                'testMarker' => '/* testFunction */',
+                'expected'   => 'functionName',
+            ],
+            'class'                 => [
+                'testMarker' => '/* testClass */',
+                'expected'   => 'ClassName',
+                'targetType' => [
+                    T_CLASS,
+                    T_STRING,
+                ],
+            ],
+            'function-unicode-name' => [
+                'testMarker' => '/* testFunctionUnicode */',
+                'expected'   => 'π',
+            ],
+        ];
+
+    }//end dataGetDeclarationName()
+
+
+    /**
+     * Test retrieving the name of JS ES6 class method.
+     *
+     * @return void
+     */
+    public function testGetDeclarationNameES6Method()
+    {
+        $target = $this->getTargetToken('/* testMethod */', [T_CLASS, T_INTERFACE, T_TRAIT, T_FUNCTION]);
+        $result = self::$phpcsFile->getDeclarationName($target);
+        $this->assertSame('methodName', $result);
+
+    }//end testGetDeclarationNameES6Method()
+
+
+}//end class
diff --git a/tests/Core/File/GetDeclarationNameTest.inc b/tests/Core/File/GetDeclarationNameTest.inc
new file mode 100644
index 0000000000..14902245bb
--- /dev/null
+++ b/tests/Core/File/GetDeclarationNameTest.inc
@@ -0,0 +1,102 @@
+<?php
+
+/* testInvalidTokenPassed */
+echo MY_CONSTANT;
+
+/* testClosure */
+$closure = function() {};
+
+/* testAnonClassWithParens */
+$anonClass = new class() {};
+
+/* testAnonClassWithParens2 */
+$class = new class() {
+    private $property = 'test';
+    public function test() {}
+};
+
+/* testAnonClassWithoutParens */
+$anonClass = new class {};
+
+/* testAnonClassExtendsWithoutParens */
+$class = new class extends SomeClass {
+    private $property = 'test';
+    public function test() {}
+};
+
+/* testFunction */
+function functionName() {}
+
+/* testFunctionReturnByRef */
+function & functionNameByRef() {}
+
+/* testClass */
+abstract class ClassName {
+    /* testMethod */
+    public function methodName() {}
+
+    /* testAbstractMethod */
+    abstract protected function abstractMethodName();
+
+    /* testMethodReturnByRef */
+    private function &MethodNameByRef();
+}
+
+/* testExtendedClass */
+class ExtendedClass extends Foo {}
+
+/* testInterface */
+interface InterfaceName {}
+
+/* testTrait */
+trait TraitName {
+    /* testFunctionEndingWithNumber */
+    function ValidNameEndingWithNumber5(){}
+}
+
+/* testClassWithNumber */
+class ClassWith1Number implements SomeInterface {}
+
+/* testInterfaceWithNumbers */
+interface InterfaceWith12345Numbers extends AnotherInterface {}
+
+/* testClassWithCommentsAndNewLines */
+class /* comment */
+
+// phpcs:ignore Standard.Cat.SniffName -- for reasons
+    ClassWithCommentsAndNewLines {}
+
+/* testFunctionFn */
+function fn() {}
+
+/* testPureEnum */
+enum Foo
+{
+    case SOME_CASE;
+}
+
+/* testBackedEnumSpaceBetweenNameAndColon */
+enum Hoo : string
+{
+    case ONE = 'one';
+    case TWO = 'two';
+}
+
+/* testBackedEnumNoSpaceBetweenNameAndColon */
+enum Suit: int implements Colorful, CardGame {}
+
+/* testFunctionReturnByRefWithReservedKeywordEach */
+function &each() {}
+
+/* testFunctionReturnByRefWithReservedKeywordParent */
+function &parent() {}
+
+/* testFunctionReturnByRefWithReservedKeywordSelf */
+function &self() {}
+
+/* testFunctionReturnByRefWithReservedKeywordStatic */
+function &static() {}
+
+/* testLiveCoding */
+// Intentional parse error. This has to be the last test in the file.
+function // Comment.
diff --git a/tests/Core/File/GetDeclarationNameTest.php b/tests/Core/File/GetDeclarationNameTest.php
new file mode 100644
index 0000000000..03736ba7ab
--- /dev/null
+++ b/tests/Core/File/GetDeclarationNameTest.php
@@ -0,0 +1,225 @@
+<?php
+/**
+ * Tests for the \PHP_CodeSniffer\Files\File::getDeclarationName method.
+ *
+ * @author    Juliette Reinders Folmer <phpcs_nospam@adviesenzo.nl>
+ * @copyright 2022-2024 PHPCSStandards Contributors
+ * @license   https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/master/licence.txt BSD Licence
+ */
+
+namespace PHP_CodeSniffer\Tests\Core\File;
+
+use PHP_CodeSniffer\Tests\Core\AbstractMethodUnitTest;
+
+/**
+ * Tests for the \PHP_CodeSniffer\Files\File:getDeclarationName method.
+ *
+ * @covers \PHP_CodeSniffer\Files\File::getDeclarationName
+ */
+class GetDeclarationNameTest extends AbstractMethodUnitTest
+{
+
+
+    /**
+     * Test receiving an expected exception when a non-supported token is passed.
+     *
+     * @return void
+     */
+    public function testInvalidTokenPassed()
+    {
+        $this->expectRunTimeException('Token type "T_STRING" is not T_FUNCTION, T_CLASS, T_INTERFACE, T_TRAIT or T_ENUM');
+
+        $target = $this->getTargetToken('/* testInvalidTokenPassed */', T_STRING);
+        self::$phpcsFile->getDeclarationName($target);
+
+    }//end testInvalidTokenPassed()
+
+
+    /**
+     * Test receiving "null" when passed an anonymous construct or in case of a parse error.
+     *
+     * @param string     $testMarker The comment which prefaces the target token in the test file.
+     * @param int|string $targetType Token type of the token to get as stackPtr.
+     *
+     * @dataProvider dataGetDeclarationNameNull
+     *
+     * @return void
+     */
+    public function testGetDeclarationNameNull($testMarker, $targetType)
+    {
+        $target = $this->getTargetToken($testMarker, $targetType);
+        $result = self::$phpcsFile->getDeclarationName($target);
+        $this->assertNull($result);
+
+    }//end testGetDeclarationNameNull()
+
+
+    /**
+     * Data provider.
+     *
+     * @see testGetDeclarationNameNull() For the array format.
+     *
+     * @return array<string, array<string, int|string>>
+     */
+    public static function dataGetDeclarationNameNull()
+    {
+        return [
+            'closure'                                => [
+                'testMarker' => '/* testClosure */',
+                'targetType' => T_CLOSURE,
+            ],
+            'anon-class-with-parentheses'            => [
+                'testMarker' => '/* testAnonClassWithParens */',
+                'targetType' => T_ANON_CLASS,
+            ],
+            'anon-class-with-parentheses-2'          => [
+                'testMarker' => '/* testAnonClassWithParens2 */',
+                'targetType' => T_ANON_CLASS,
+            ],
+            'anon-class-without-parentheses'         => [
+                'testMarker' => '/* testAnonClassWithoutParens */',
+                'targetType' => T_ANON_CLASS,
+            ],
+            'anon-class-extends-without-parentheses' => [
+                'testMarker' => '/* testAnonClassExtendsWithoutParens */',
+                'targetType' => T_ANON_CLASS,
+            ],
+            'live-coding'                            => [
+                'testMarker' => '/* testLiveCoding */',
+                'targetType' => T_FUNCTION,
+            ],
+        ];
+
+    }//end dataGetDeclarationNameNull()
+
+
+    /**
+     * Test retrieving the name of a function or OO structure.
+     *
+     * @param string          $testMarker The comment which prefaces the target token in the test file.
+     * @param string          $expected   Expected function output.
+     * @param int|string|null $targetType Token type of the token to get as stackPtr.
+     *
+     * @dataProvider dataGetDeclarationName
+     *
+     * @return void
+     */
+    public function testGetDeclarationName($testMarker, $expected, $targetType=null)
+    {
+        if (isset($targetType) === false) {
+            $targetType = [
+                T_CLASS,
+                T_INTERFACE,
+                T_TRAIT,
+                T_ENUM,
+                T_FUNCTION,
+            ];
+        }
+
+        $target = $this->getTargetToken($testMarker, $targetType);
+        $result = self::$phpcsFile->getDeclarationName($target);
+        $this->assertSame($expected, $result);
+
+    }//end testGetDeclarationName()
+
+
+    /**
+     * Data provider.
+     *
+     * @see testGetDeclarationName() For the array format.
+     *
+     * @return array<string, array<string, string>>
+     */
+    public static function dataGetDeclarationName()
+    {
+        return [
+            'function'                                                  => [
+                'testMarker' => '/* testFunction */',
+                'expected'   => 'functionName',
+            ],
+            'function-return-by-reference'                              => [
+                'testMarker' => '/* testFunctionReturnByRef */',
+                'expected'   => 'functionNameByRef',
+            ],
+            'class'                                                     => [
+                'testMarker' => '/* testClass */',
+                'expected'   => 'ClassName',
+            ],
+            'method'                                                    => [
+                'testMarker' => '/* testMethod */',
+                'expected'   => 'methodName',
+            ],
+            'abstract-method'                                           => [
+                'testMarker' => '/* testAbstractMethod */',
+                'expected'   => 'abstractMethodName',
+            ],
+            'method-return-by-reference'                                => [
+                'testMarker' => '/* testMethodReturnByRef */',
+                'expected'   => 'MethodNameByRef',
+            ],
+            'extended-class'                                            => [
+                'testMarker' => '/* testExtendedClass */',
+                'expected'   => 'ExtendedClass',
+            ],
+            'interface'                                                 => [
+                'testMarker' => '/* testInterface */',
+                'expected'   => 'InterfaceName',
+            ],
+            'trait'                                                     => [
+                'testMarker' => '/* testTrait */',
+                'expected'   => 'TraitName',
+            ],
+            'function-name-ends-with-number'                            => [
+                'testMarker' => '/* testFunctionEndingWithNumber */',
+                'expected'   => 'ValidNameEndingWithNumber5',
+            ],
+            'class-with-numbers-in-name'                                => [
+                'testMarker' => '/* testClassWithNumber */',
+                'expected'   => 'ClassWith1Number',
+            ],
+            'interface-with-numbers-in-name'                            => [
+                'testMarker' => '/* testInterfaceWithNumbers */',
+                'expected'   => 'InterfaceWith12345Numbers',
+            ],
+            'class-with-comments-and-new-lines'                         => [
+                'testMarker' => '/* testClassWithCommentsAndNewLines */',
+                'expected'   => 'ClassWithCommentsAndNewLines',
+            ],
+            'function-named-fn'                                         => [
+                'testMarker' => '/* testFunctionFn */',
+                'expected'   => 'fn',
+            ],
+            'enum-pure'                                                 => [
+                'testMarker' => '/* testPureEnum */',
+                'expected'   => 'Foo',
+            ],
+            'enum-backed-space-between-name-and-colon'                  => [
+                'testMarker' => '/* testBackedEnumSpaceBetweenNameAndColon */',
+                'expected'   => 'Hoo',
+            ],
+            'enum-backed-no-space-between-name-and-colon'               => [
+                'testMarker' => '/* testBackedEnumNoSpaceBetweenNameAndColon */',
+                'expected'   => 'Suit',
+            ],
+            'function-return-by-reference-with-reserved-keyword-each'   => [
+                'testMarker' => '/* testFunctionReturnByRefWithReservedKeywordEach */',
+                'expected'   => 'each',
+            ],
+            'function-return-by-reference-with-reserved-keyword-parent' => [
+                'testMarker' => '/* testFunctionReturnByRefWithReservedKeywordParent */',
+                'expected'   => 'parent',
+            ],
+            'function-return-by-reference-with-reserved-keyword-self'   => [
+                'testMarker' => '/* testFunctionReturnByRefWithReservedKeywordSelf */',
+                'expected'   => 'self',
+            ],
+            'function-return-by-reference-with-reserved-keyword-static' => [
+                'testMarker' => '/* testFunctionReturnByRefWithReservedKeywordStatic */',
+                'expected'   => 'static',
+            ],
+        ];
+
+    }//end dataGetDeclarationName()
+
+
+}//end class