diff --git a/lib/tests/accesslib_test.php b/lib/tests/accesslib_test.php
index a07aea923f4..07815ab246e 100644
--- a/lib/tests/accesslib_test.php
+++ b/lib/tests/accesslib_test.php
@@ -4067,6 +4067,204 @@ class core_accesslib_testcase extends advanced_testcase {
         $this->assertEquals($expectedteacher, get_profile_roles($coursecontext));
     }
 
+    /**
+     * Data provider for is_parent_of context checks.
+     *
+     * @return  array
+     */
+    public function is_parent_of_provider(): array {
+        $provideboth = function(string $desc, string $contextpath, string $testpath, bool $expected): array {
+            return [
+                "includeself: true; {$desc}" => [
+                    $contextpath,
+                    $testpath,
+                    true,
+                    $expected,
+                ],
+                "includeself: false; {$desc}" => [
+                    $contextpath,
+                    $testpath,
+                    false,
+                    $expected,
+                ],
+            ];
+        };
+
+        return array_merge(
+            [
+                'includeself: true, testing self' => [
+                    '/1/4/17/291/1001/17105',
+                    '/1/4/17/291/1001/17105',
+                    true,
+                    true,
+                ],
+                'includeself: false, testing self' => [
+                    '/1/4/17/291/1001/17105',
+                    '/1/4/17/291/1001/17105',
+                    false,
+                    false,
+                ],
+            ],
+            $provideboth(
+                'testing parent',
+                '/1/4/17/291/1001/17105',
+                '/1/4/17/291/1001',
+                false
+            ),
+            $provideboth(
+                'testing child',
+                '/1/4/17/291/1001',
+                '/1/4/17/291/1001/17105',
+                true
+            ),
+            $provideboth(
+                'testing grandchild',
+                '/1',
+                '/1/4/17/291/1001/17105',
+                true
+            )
+        );
+    }
+
+    /**
+     * Ensure that the is_parent_of() function works as anticipated.
+     *
+     * @dataProvider is_parent_of_provider
+     * @param   string $contextpath The path of the context being compared with
+     * @param   string $testpath The path of the context being compared
+     * @param   bool $testself Whether to check the current context
+     * @param   bool $expected The expected result
+     */
+    public function test_is_parent_of(string $contextpath, string $testpath, bool $testself, bool $expected): void {
+        $context = $this->getMockBuilder(\context::class)
+            ->disableOriginalConstructor()
+            ->setMethods([
+                'get_url',
+                'get_capabilities',
+            ])
+            ->getMock();
+
+        $rcp = new ReflectionProperty($context, '_path');
+        $rcp->setAccessible(true);
+        $rcp->setValue($context, $contextpath);
+
+        $comparisoncontext = $this->getMockBuilder(\context::class)
+            ->disableOriginalConstructor()
+            ->setMethods([
+                'get_url',
+                'get_capabilities',
+            ])
+            ->getMock();
+
+        $rcp = new ReflectionProperty($comparisoncontext, '_path');
+        $rcp->setAccessible(true);
+        $rcp->setValue($comparisoncontext, $testpath);
+
+        $this->assertEquals($expected, $context->is_parent_of($comparisoncontext, $testself));
+    }
+
+    /**
+     * Data provider for is_child_of context checks.
+     *
+     * @return  array
+     */
+    public function is_child_of_provider(): array {
+        $provideboth = function(string $desc, string $contextpath, string $testpath, bool $expected): array {
+            return [
+                "includeself: true; {$desc}" => [
+                    $contextpath,
+                    $testpath,
+                    true,
+                    $expected,
+                ],
+                "includeself: false; {$desc}" => [
+                    $contextpath,
+                    $testpath,
+                    false,
+                    $expected,
+                ],
+            ];
+        };
+
+        return array_merge(
+            [
+                'includeself: true, testing self' => [
+                    '/1/4/17/291/1001/17105',
+                    '/1/4/17/291/1001/17105',
+                    true,
+                    true,
+                ],
+                'includeself: false, testing self' => [
+                    '/1/4/17/291/1001/17105',
+                    '/1/4/17/291/1001/17105',
+                    false,
+                    false,
+                ],
+            ],
+            $provideboth(
+                'testing child',
+                '/1/4/17/291/1001/17105',
+                '/1/4/17/291/1001',
+                true
+            ),
+            $provideboth(
+                'testing parent',
+                '/1/4/17/291/1001',
+                '/1/4/17/291/1001/17105',
+                false
+            ),
+            $provideboth(
+                'testing grandchild',
+                '/1/4/17/291/1001/17105',
+                '/1',
+                true
+            ),
+            $provideboth(
+                'testing grandparent',
+                '/1',
+                '/1/4/17/291/1001/17105',
+                false
+            )
+        );
+    }
+
+    /**
+     * Ensure that the is_child_of() function works as anticipated.
+     *
+     * @dataProvider is_child_of_provider
+     * @param   string $contextpath The path of the context being compared with
+     * @param   string $testpath The path of the context being compared
+     * @param   bool $testself Whether to check the current context
+     * @param   bool $expected The expected result
+     */
+    public function test_is_child_of(string $contextpath, string $testpath, bool $testself, bool $expected): void {
+        $context = $this->getMockBuilder(\context::class)
+            ->disableOriginalConstructor()
+            ->setMethods([
+                'get_url',
+                'get_capabilities',
+            ])
+            ->getMock();
+
+        $rcp = new ReflectionProperty($context, '_path');
+        $rcp->setAccessible(true);
+        $rcp->setValue($context, $contextpath);
+
+        $comparisoncontext = $this->getMockBuilder(\context::class)
+            ->disableOriginalConstructor()
+            ->setMethods([
+                'get_url',
+                'get_capabilities',
+            ])
+            ->getMock();
+
+        $rcp = new ReflectionProperty($comparisoncontext, '_path');
+        $rcp->setAccessible(true);
+        $rcp->setValue($comparisoncontext, $testpath);
+
+        $this->assertEquals($expected, $context->is_child_of($comparisoncontext, $testself));
+    }
+
     /**
      * Ensure that the get_parent_contexts() function limits the number of queries it performs.
      */