Try to fix the build

Author: Willem Stuursma

composer.json

@@ -59,7 +59,8 @@
         "php-mock/php-mock-phpunit": "^2.1",
         "phpunit/phpunit": "^7.4",
         "predis/predis": "^1.1",
-        "squizlabs/php_codesniffer": "^3.3"
+        "squizlabs/php_codesniffer": "^3.3",
+        "symfony/event-dispatcher": "^2.8"
     },
     "suggest": {
         "ext-igbinary": "To use this library with PHP Redis igbinary serializer enabled.",

tests/mutex/MutexConcurrencyTest.php

@@ -286,26 +286,30 @@ function ($uri) {
             return new PredisMutex($clients, 'test', $timeout);
         }];
 
-        $cases['PHPRedisMutex'] = [function ($timeout = 3) use ($uris): Mutex {
-            /** @var Redis[] $apis */
-            $apis = array_map(
-                function (string $uri): Redis {
-                    $redis = new Redis();
-
-                    $uri = parse_url($uri);
-                    if (!empty($uri['port'])) {
-                        $redis->connect($uri['host'], $uri['port']);
-                    } else {
-                        $redis->connect($uri['host']);
-                    }
-
-                    return $redis;
-                },
-                $uris
-            );
-
-            return new PHPRedisMutex($apis, 'test', $timeout);
-        }];
+        if (class_exists(Redis::class)) {
+            $cases['PHPRedisMutex'] = [
+                function ($timeout = 3) use ($uris): Mutex {
+                    /** @var Redis[] $apis */
+                    $apis = array_map(
+                        function (string $uri): Redis {
+                            $redis = new Redis();
+
+                            $uri = parse_url($uri);
+                            if (!empty($uri['port'])) {
+                                $redis->connect($uri['host'], $uri['port']);
+                            } else {
+                                $redis->connect($uri['host']);
+                            }
+
+                            return $redis;
+                        },
+                        $uris
+                    );
+
+                    return new PHPRedisMutex($apis, 'test', $timeout);
+                }
+            ];
+        }
 
         if (getenv('MYSQL_DSN')) {
             $cases['MySQLMutex'] = [function ($timeout = 3): Mutex {

tests/mutex/MutexTest.php

@@ -126,26 +126,30 @@ function ($uri) {
                 return new PredisMutex($clients, 'test', self::TIMEOUT);
             }];
 
-            $cases['PHPRedisMutex'] = [function () use ($uris): Mutex {
-                /** @var Redis[] $apis */
-                $apis = array_map(
-                    function ($uri) {
-                        $redis = new Redis();
-
-                        $uri = parse_url($uri);
-                        if (!empty($uri['port'])) {
-                            $redis->connect($uri['host'], $uri['port']);
-                        } else {
-                            $redis->connect($uri['host']);
-                        }
-
-                        return $redis;
-                    },
-                    $uris
-                );
-
-                return new PHPRedisMutex($apis, 'test', self::TIMEOUT);
-            }];
+            if (class_exists(Redis::class)) {
+                $cases['PHPRedisMutex'] = [
+                    function () use ($uris): Mutex {
+                        /** @var Redis[] $apis */
+                        $apis = array_map(
+                            function ($uri) {
+                                $redis = new Redis();
+
+                                $uri = parse_url($uri);
+                                if (!empty($uri['port'])) {
+                                    $redis->connect($uri['host'], $uri['port']);
+                                } else {
+                                    $redis->connect($uri['host']);
+                                }
+
+                                return $redis;
+                            },
+                            $uris
+                        );
+
+                        return new PHPRedisMutex($apis, 'test', self::TIMEOUT);
+                    }
+                ];
+            }
         }
 
         if (getenv('MYSQL_DSN')) {