From 7c58a507787a58cc3541f31ceea4b2d6819902a8 Mon Sep 17 00:00:00 2001
From: Wojciech Nagrodzki <278594+wnagrodzki@users.noreply.github.com>
Date: Sun, 26 Aug 2018 12:08:07 +0200
Subject: [PATCH] Uncoupled DiskLogger from FileManager

---
 Logger/Loggers/DiskLogger/DiskLogger.swift | 10 ++++++----
 Logger/Loggers/DiskLogger/FileSystem.swift |  9 +++++++--
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/Logger/Loggers/DiskLogger/DiskLogger.swift b/Logger/Loggers/DiskLogger/DiskLogger.swift
index 20e864e..dfc6859 100644
--- a/Logger/Loggers/DiskLogger/DiskLogger.swift
+++ b/Logger/Loggers/DiskLogger/DiskLogger.swift
@@ -30,6 +30,7 @@ public final class DiskLogger: Logger {
     private let fileURL: URL
     private let fileSizeLimit: UInt64
     private let rotations: Int
+    private let fileSystem: FileSystem
     private let formatter: DateFormatter
     private let queue = DispatchQueue(label: "com.wnagrodzki.DiskLogger", qos: .background, attributes: [], autoreleaseFrequency: .workItem, target: nil)
     private var buffer = Data()
@@ -41,10 +42,11 @@ public final class DiskLogger: Logger {
     ///   - fileURL: URL of the log file.
     ///   - fileSizeLimit: Maximum size log file can reach in bytes. Attempt to exceeding that limit triggers log files rotation.
     ///   - rotations: Number of times log files are rotated before being removed.
-    public init(fileURL: URL, fileSizeLimit: UInt64, rotations: Int) {
+    public init(fileURL: URL, fileSizeLimit: UInt64, rotations: Int, fileSystem: FileSystem) {
         self.fileURL = fileURL
         self.fileSizeLimit = fileSizeLimit
         self.rotations = rotations
+        self.fileSystem = fileSystem
         formatter = DateFormatter()
         formatter.dateFormat = "yyyy-MM-dd HH:mm:ss.SSS"
         formatter.timeZone = TimeZone(secondsFromGMT: 0)
@@ -80,8 +82,8 @@ public final class DiskLogger: Logger {
     
     private func openFileWriter() throws {
         guard fileWriter == nil else { return }
-        if FileManager.default.fileExists(atPath: fileURL.path) == false {
-            FileManager.default.createFile(atPath: fileURL.path, contents: nil, attributes: nil)
+        if fileSystem.itemExists(at: fileURL) == false {
+            _ = fileSystem.createFile(at: fileURL)
         }
         fileWriter = try FileWriter(fileURL: fileURL, fileSizeLimit: fileSizeLimit)
     }
@@ -97,7 +99,7 @@ public final class DiskLogger: Logger {
     }
     
     private func rotateLogFiles() throws {
-        let logrotate = Logrotate(fileURL: fileURL, rotations: rotations, fileSystem: FileManager.default)
+        let logrotate = Logrotate(fileURL: fileURL, rotations: rotations, fileSystem: fileSystem)
         try logrotate.rotate()
     }
 }
diff --git a/Logger/Loggers/DiskLogger/FileSystem.swift b/Logger/Loggers/DiskLogger/FileSystem.swift
index d78c5f4..b47b316 100644
--- a/Logger/Loggers/DiskLogger/FileSystem.swift
+++ b/Logger/Loggers/DiskLogger/FileSystem.swift
@@ -24,15 +24,20 @@
 
 import Foundation
 
-protocol FileSystem {
+public protocol FileSystem {
     func itemExists(at URL: URL) -> Bool
     func removeItem(at URL: URL) throws
     func moveItem(at srcURL: URL, to dstURL: URL) throws
+    func createFile(at URL: URL) -> Bool
 }
 
 extension FileManager: FileSystem {
     
-    func itemExists(at URL: URL) -> Bool {
+    public func itemExists(at URL: URL) -> Bool {
         return fileExists(atPath: URL.path)
     }
+    
+    public func createFile(at URL: URL) -> Bool {
+        return createFile(atPath: URL.path, contents: nil, attributes: nil)
+    }
 }