diff --git a/core/lib/Drupal/Core/Cache/Cache.php b/core/lib/Drupal/Core/Cache/Cache.php
index eeae1a1ff1b..8f8e97e8668 100644
--- a/core/lib/Drupal/Core/Cache/Cache.php
+++ b/core/lib/Drupal/Core/Cache/Cache.php
@@ -20,16 +20,14 @@ class Cache {
   /**
    * Merges arrays of cache contexts and removes duplicates.
    *
-   * @param array $a
-   *   Cache contexts array to merge.
-   * @param array $b
-   *   Cache contexts array to merge.
+   * @param string[] ...
+   *   Cache contexts arrays to merge.
    *
    * @return string[]
    *   The merged array of cache contexts.
    */
-  public static function mergeContexts(array $a = [], array $b = []) {
-    $cache_contexts = array_unique(array_merge($a, $b));
+  public static function mergeContexts(array ...$cache_contexts) {
+    $cache_contexts = array_unique(array_merge(...$cache_contexts));
     assert(\Drupal::service('cache_contexts_manager')->assertValidTokens($cache_contexts));
     sort($cache_contexts);
     return $cache_contexts;
@@ -46,18 +44,15 @@ class Cache {
    * allows items to be invalidated based on all tags attached to the content
    * they're constituted from.
    *
-   * @param array $a
-   *   Cache tags array to merge.
-   * @param array $b
-   *   Cache tags array to merge.
+   * @param string[] ...
+   *   Cache tags arrays to merge.
    *
    * @return string[]
    *   The merged array of cache tags.
    */
-  public static function mergeTags(array $a = [], array $b = []) {
-    assert(Inspector::assertAllStrings($a) && Inspector::assertAllStrings($b), 'Cache tags must be valid strings');
-
-    $cache_tags = array_unique(array_merge($a, $b));
+  public static function mergeTags(array ...$cache_tags) {
+    $cache_tags = array_unique(array_merge(...$cache_tags));
+    assert(Inspector::assertAllStrings($cache_tags), 'Cache tags must be valid strings');
     sort($cache_tags);
     return $cache_tags;
   }
@@ -67,25 +62,21 @@ class Cache {
    *
    * Ensures infinite max-age (Cache::PERMANENT) is taken into account.
    *
-   * @param int $a
-   *   Max age value to merge.
-   * @param int $b
-   *   Max age value to merge.
+   * @param int ...
+   *   Max age values to merge.
    *
    * @return int
    *   The minimum max-age value.
    */
-  public static function mergeMaxAges($a = Cache::PERMANENT, $b = Cache::PERMANENT) {
-    // If one of the values is Cache::PERMANENT, return the other value.
-    if ($a === Cache::PERMANENT) {
-      return $b;
-    }
-    if ($b === Cache::PERMANENT) {
-      return $a;
-    }
+  public static function mergeMaxAges(...$max_ages) {
+    // Remove Cache::PERMANENT values to return the correct minimum value.
+    $max_ages = array_filter($max_ages, function ($max_age) {
+      return $max_age !== Cache::PERMANENT;
+    });
 
-    // If none or the values are Cache::PERMANENT, return the minimum value.
-    return min($a, $b);
+    // If there are no max ages left return Cache::PERMANENT, otherwise return
+    // the minimum value.
+    return empty($max_ages) ? Cache::PERMANENT : min($max_ages);
   }
 
   /**
diff --git a/core/tests/Drupal/Tests/Core/Cache/CacheTest.php b/core/tests/Drupal/Tests/Core/Cache/CacheTest.php
index e211db418b4..12dc9bb5399 100644
--- a/core/tests/Drupal/Tests/Core/Cache/CacheTest.php
+++ b/core/tests/Drupal/Tests/Core/Cache/CacheTest.php
@@ -4,6 +4,9 @@ namespace Drupal\Tests\Core\Cache;
 
 use Drupal\Core\Cache\Cache;
 use Drupal\Tests\UnitTestCase;
+use Prophecy\Argument;
+use Drupal\Core\Cache\Context\CacheContextsManager;
+use Drupal\Core\DependencyInjection\Container;
 
 /**
  * @coversDefaultClass \Drupal\Core\Cache\Cache
@@ -48,12 +51,13 @@ class CacheTest extends UnitTestCase {
   public function mergeTagsProvider() {
     return [
       [[], [], []],
-      [['bar'], ['foo'], ['bar', 'foo']],
-      [['foo'], ['bar'], ['bar', 'foo']],
-      [['foo'], ['bar', 'foo'], ['bar', 'foo']],
-      [['foo'], ['foo', 'bar'], ['bar', 'foo']],
-      [['bar', 'foo'], ['foo', 'bar'], ['bar', 'foo']],
-      [['foo', 'bar'], ['foo', 'bar'], ['bar', 'foo']],
+      [['bar', 'foo'], ['bar'], ['foo']],
+      [['bar', 'foo'], ['foo'], ['bar']],
+      [['bar', 'foo'], ['foo'], ['bar', 'foo']],
+      [['bar', 'foo'], ['foo'], ['foo', 'bar']],
+      [['bar', 'foo'], ['bar', 'foo'], ['foo', 'bar']],
+      [['bar', 'foo'], ['foo', 'bar'], ['foo', 'bar']],
+      [['bar', 'foo', 'llama'], ['bar', 'foo'], ['foo', 'bar'], ['llama', 'foo']],
     ];
   }
 
@@ -62,8 +66,8 @@ class CacheTest extends UnitTestCase {
    *
    * @dataProvider mergeTagsProvider
    */
-  public function testMergeTags(array $a, array $b, array $expected) {
-    $this->assertEquals($expected, Cache::mergeTags($a, $b));
+  public function testMergeTags(array $expected, ...$cache_tags) {
+    $this->assertEquals($expected, Cache::mergeTags(...$cache_tags));
   }
 
   /**
@@ -77,14 +81,22 @@ class CacheTest extends UnitTestCase {
       [60, 60, 60],
       [0, 0, 0],
 
-      [60, 0, 0],
       [0, 60, 0],
+      [0, 0, 60],
 
-      [Cache::PERMANENT, 0, 0],
       [0, Cache::PERMANENT, 0],
+      [0, 0, Cache::PERMANENT],
 
-      [Cache::PERMANENT, 60, 60],
       [60, Cache::PERMANENT, 60],
+      [60, 60, Cache::PERMANENT],
+
+      [Cache::PERMANENT, Cache::PERMANENT, Cache::PERMANENT, Cache::PERMANENT],
+      [30, 60, 60, 30],
+      [0, 0, 0, 0],
+
+      [60, Cache::PERMANENT, 60, Cache::PERMANENT],
+      [60, 60, Cache::PERMANENT, Cache::PERMANENT],
+      [60, Cache::PERMANENT, Cache::PERMANENT, 60],
     ];
   }
 
@@ -93,8 +105,47 @@ class CacheTest extends UnitTestCase {
    *
    * @dataProvider mergeMaxAgesProvider
    */
-  public function testMergeMaxAges($a, $b, $expected) {
-    $this->assertSame($expected, Cache::mergeMaxAges($a, $b));
+  public function testMergeMaxAges($expected, ...$max_ages) {
+    $this->assertSame($expected, Cache::mergeMaxAges(...$max_ages));
+  }
+
+  /**
+   * Provides a list of pairs of cache contexts arrays to be merged.
+   *
+   * @return array
+   */
+  public function mergeCacheContextsProvide() {
+    return [
+      [[], [], []],
+      [['foo'], [], ['foo']],
+      [['foo'], ['foo'], []],
+
+      [['bar', 'foo'], ['foo'], ['bar']],
+      [['bar', 'foo'], ['bar'], ['foo']],
+
+      [['foo.bar', 'foo.foo'], ['foo.foo'], ['foo.bar']],
+      [['foo.bar', 'foo.foo'], ['foo.bar'], ['foo.foo']],
+
+      [['bar', 'foo', 'llama'], [], ['foo', 'bar', 'llama']],
+      [['bar', 'foo', 'llama'], ['foo', 'bar', 'llama'], []],
+
+      [['bar', 'foo', 'llama'], ['foo'], ['foo', 'bar', 'llama']],
+      [['bar', 'foo', 'llama'], ['foo', 'bar', 'llama'], ['foo']],
+    ];
+  }
+
+  /**
+   * @covers ::mergeContexts
+   *
+   * @dataProvider mergeCacheContextsProvide
+   */
+  public function testMergeCacheContexts(array $expected, ...$contexts) {
+    $cache_contexts_manager = $this->prophesize(CacheContextsManager::class);
+    $cache_contexts_manager->assertValidTokens(Argument::any())->willReturn(TRUE);
+    $container = $this->prophesize(Container::class);
+    $container->get('cache_contexts_manager')->willReturn($cache_contexts_manager->reveal());
+    \Drupal::setContainer($container->reveal());
+    $this->assertSame($expected, Cache::mergeContexts(...$contexts));
   }
 
   /**