exists api

Sources/LiquidKit/FileStorage.swift

@@ -10,18 +10,21 @@ import struct Foundation.Data
 public protocol FileStorage {
     var context: FileStorageContext { get }
 
-    //returns a key as a full url
+    /// returns a key as a full url
     func resolve(key: String) -> String
 
-    // uploads the data under the given key
+    /// uploads the data under the given key
     func upload(key: String, data: Data) -> EventLoopFuture<String>
 
-    // create a new directory for a given key
+    /// create a new directory for a given key
     func createDirectory(key: String) -> EventLoopFuture<Void>
 
-    // list the contents of a given object for a key
+    /// list the contents of a given object for a key
     func list(key: String?) -> EventLoopFuture<[String]>
 
-    // deletes the data under the given key
+    /// deletes the data under the given key
     func delete(key: String) -> EventLoopFuture<Void>
+
+    /// check if a given key exists
+    func exists(key: String) -> EventLoopFuture<Bool>
 }