diff --git a/tests/phpunit/tests/functions/wpArrayGet.php b/tests/phpunit/tests/functions/wpArrayGet.php
new file mode 100644
index 0000000000..8ebd9c4386
--- /dev/null
+++ b/tests/phpunit/tests/functions/wpArrayGet.php
@@ -0,0 +1,286 @@
+<?php
+
+/**
+ * Tests for the _wp_array_get() function
+ *
+ * @since 5.6.0
+ *
+ * @group functions.php
+ * @covers ::_wp_array_get
+ */
+class Tests_Functions_wpArrayGet extends WP_UnitTestCase {
+
+	/**
+	 * Test _wp_array_get() with invalid parameters.
+	 *
+	 * @ticket 51720
+	 */
+	public function test_wp_array_get_invalid_parameters() {
+		$this->assertSame(
+			_wp_array_get(
+				null,
+				array( 'a' )
+			),
+			null
+		);
+
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'key' => 4,
+				),
+				null
+			),
+			null
+		);
+
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'key' => 4,
+				),
+				array()
+			),
+			null
+		);
+
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'key' => 4,
+				),
+				array(),
+				true
+			),
+			true
+		);
+	}
+
+	/**
+	 * Test _wp_array_get() with non subtree paths.
+	 *
+	 * @ticket 51720
+	 */
+	public function test_wp_array_get_simple_non_subtree() {
+		// Simple non sub tree test.
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'key' => 4,
+				),
+				array( 'key' ),
+			),
+			4
+		);
+
+		// Simple non sub tree not found.
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'key' => 4,
+				),
+				array( 'invalid' ),
+			),
+			null
+		);
+
+		// Simple non sub tree not found with a default.
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'key' => 4,
+				),
+				array( 'invalid' ),
+				1
+			),
+			1
+		);
+
+		// Simple non sub tree integer path.
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'a',
+					'b',
+					'c',
+				),
+				array( 1 )
+			),
+			'b'
+		);
+	}
+
+	/**
+	 * Test _wp_array_get() with zero strings.
+	 *
+	 * @ticket 51720
+	 */
+	public function test_wp_array_get_handle_zeros() {
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'-0' => 'a',
+					'0'  => 'b',
+				),
+				array( 0 )
+			),
+			'b'
+		);
+
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'-0' => 'a',
+					'0'  => 'b',
+				),
+				array( -0 )
+			),
+			'b'
+		);
+
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'-0' => 'a',
+					'0'  => 'b',
+				),
+				array( '-0' )
+			),
+			'a'
+		);
+
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'-0' => 'a',
+					'0'  => 'b',
+				),
+				array( '0' )
+			),
+			'b'
+		);
+	}
+
+
+	/**
+	 * Test _wp_array_get() with subtrees.
+	 *
+	 * @ticket 51720
+	 */
+	public function test_wp_array_get_subtree() {
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'a' => array(
+						'b' => array(
+							'c' => 1,
+						),
+					),
+				),
+				array( 'a', 'b' )
+			),
+			array( 'c' => 1 )
+		);
+
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'a' => array(
+						'b' => array(
+							'c' => 1,
+						),
+					),
+				),
+				array( 'a', 'b', 'c' )
+			),
+			1
+		);
+
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'a' => array(
+						'b' => array(
+							'c' => 1,
+						),
+					),
+				),
+				array( 'a', 'b', 'c', 'd' )
+			),
+			null
+		);
+	}
+
+	/**
+	 * Test _wp_array_get() with null values.
+	 *
+	 * @ticket 51720
+	 */
+	public function test_wp_array_get_null() {
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'key' => null,
+				),
+				array( 'key' ),
+				true
+			),
+			null
+		);
+
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'key' => null,
+				),
+				array( 'key', 'subkey' ),
+				true
+			),
+			true
+		);
+
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'key' => array(
+						null => 4,
+					),
+				),
+				array( 'key', null ),
+				true
+			),
+			4
+		);
+	}
+
+	/**
+	 * Test _wp_array_get() with empty paths.
+	 *
+	 * @ticket 51720
+	 */
+	public function test_wp_array_get_empty_paths() {
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'a' => 4,
+				),
+				array()
+			),
+			null
+		);
+
+		$this->assertSame(
+			_wp_array_get(
+				array(
+					'a' => array(
+						'b' => array(
+							'c' => 1,
+						),
+					),
+				),
+				array( 'a', 'b', array() )
+			),
+			null
+		);
+	}
+}