Don't use flushdb when clearing the cache

Some systems will have FLUSHDB disabled and this also makes it easier to share a database between applications without flushing all cache if cache key prefixes are used.

CHANGELOG.md

@@ -1752,6 +1752,7 @@ The major version bump is due to dropped support for PHP `7.0` and `7.1` and a s
 * Removed support for "piped" validation rules.
 * New syntax for passing parameters to middleware.
 * New syntax for passing parameters to validation rules.
+* The Redis cache `clear` implementation will no longer flush the entire database but instead just deleted the cached keys.
 
 #### Bugfixes
 

src/mako/cache/stores/Redis.php

@@ -9,6 +9,7 @@
 
 use mako\redis\Redis as RedisClient;
 
+use function array_chunk;
 use function is_numeric;
 use function serialize;
 use function unserialize;
@@ -112,6 +113,14 @@ public function remove(string $key): bool
 	 */
 	public function clear(): bool
 	{
-		return (bool) $this->redis->flushdb();
+		$keys = $this->redis->keys($this->getPrefixedKey('*'));
+
+		if (!empty($keys)) {
+			foreach (array_chunk($keys, 100) as $chunk) {
+				$this->redis->del(...$chunk);
+			}
+		}
+
+		return true;
 	}
 }

tests/unit/cache/stores/RedisTest.php

@@ -298,10 +298,30 @@ public function testClear(): void
 	{
 		$client = $this->getRedisClient();
 
-		$client->shouldReceive('flushdb')->once();
+		$client->shouldReceive('keys')->once()->with('*')->andReturn(['foo', 'bar']);
+
+		$client->shouldReceive('del')->once()->with('foo', 'bar')->andReturn(2);
 
 		$redis = new Redis($client);
 
 		$redis->clear();
 	}
+
+	/**
+	 *
+	 */
+	public function testClearWithPrefix(): void
+	{
+		$client = $this->getRedisClient();
+
+		$client->shouldReceive('keys')->once()->with('prefix.*')->andReturn(['prefix.foo', 'prefix.bar']);
+
+		$client->shouldReceive('del')->once()->with('prefix.foo', 'prefix.bar')->andReturn(2);
+
+		$redis = new Redis($client);
+
+		$redis->setPrefix('prefix');
+
+		$redis->clear();
+	}
 }