Merge pull request jduquennoy#29 from serges147/master

Author: jduquennoy

Log4swift/Logger.swift

@@ -44,12 +44,13 @@ A logger is identified by a UTI identifier, it defines a threshold level and a d
 
   /// The UTI string that identifies the logger. Example : product.module.feature
   public let identifier: String
-  
+
   internal var parent: Logger?
 
   private var thresholdLevelStorage: LogLevel
   private var appendersStorage: [Appender]
   private var asynchronousStorage = false
+  private var timeProviderStorage: () -> Date = Date.init
 
   /// If asynchronous is true, only the minimum of work will be done on the main thread, the rest will be deffered to a low priority background thread.
   /// The order of the messages will be preserved in async mode.
@@ -103,7 +104,30 @@ A logger is identified by a UTI identifier, it defines a threshold level and a d
     }
   }
 
-  
+  /// Gets/sets external time provider for log messages.
+  /// Default behavior is just `Date()`.
+  ///
+  /// Allows to "mock" the time - could be useful in unit tests
+  /// which may run on some "virtual" time instead of real one.
+  ///
+  /// Child loggers inherit this value so it's possible to set it only once
+  /// (on the `rootLogger` for example) - entire sub-hierarchy of loggers will have it.
+  ///
+  @objc
+  public var timeProvider: () -> Date {
+    get {
+      if let parent = self.parent {
+        return parent.timeProvider
+      } else {
+        return self.timeProviderStorage
+      }
+    }
+    set {
+      self.breakDependencyWithParent()
+      self.timeProviderStorage = newValue
+    }
+  }
+
   /// Creates a new logger with the given identifier, log level and appenders.
   /// The identifier will not be modifiable, and should not be an empty string.
   @objc
@@ -236,7 +260,7 @@ A logger is identified by a UTI identifier, it defines a threshold level and a d
       var info: LogInfoDictionary = [
         .LoggerName: self.identifier,
         .LogLevel: level,
-        .Timestamp: NSDate().timeIntervalSince1970,
+        .Timestamp: self.timeProvider().timeIntervalSince1970,
         .ThreadId: currentThreadId(),
         .ThreadName: currentThreadName()
       ]
@@ -265,7 +289,7 @@ A logger is identified by a UTI identifier, it defines a threshold level and a d
       var info: LogInfoDictionary = [
         .LoggerName: self.identifier,
         .LogLevel: level,
-        .Timestamp: NSDate().timeIntervalSince1970,
+        .Timestamp: self.timeProvider().timeIntervalSince1970,
         .ThreadId: currentThreadId(),
         .ThreadName: currentThreadName()
       ]
@@ -304,6 +328,7 @@ A logger is identified by a UTI identifier, it defines a threshold level and a d
     }
     self.thresholdLevelStorage = parent.thresholdLevel
     self.appendersStorage = parent.appenders
+    self.timeProviderStorage = parent.timeProvider
     self.parent = nil
   }
 

Log4swiftTests/LoggerTests.swift

@@ -539,6 +539,18 @@ class LoggerTests: XCTestCase {
     XCTAssertTrue(sonIsAsynchronous)
   }
 
+  func testLoggerWithParentUsesParentTimeProvider() {
+    let parentLogger = Logger(identifier: "parent.logger", level: .Info, appenders: [MemoryAppender()])
+    let sonLogger = Logger(parentLogger: parentLogger, identifier: "son.logger")
+
+    // Execute
+    let testDate = Date(timeIntervalSince1970: 42)
+    parentLogger.timeProvider = { return testDate }
+
+    // Validate
+    XCTAssertEqual(sonLogger.timeProvider(), testDate)
+  }
+
   func testChangingSonLoggerParameterBreakLinkWithParent() {
     let parentLogger = Logger(identifier: "parent.logger", level: .Info, appenders: [MemoryAppender()])
     let sonLogger = Logger(parentLogger: parentLogger, identifier: "son.logger")
@@ -565,7 +577,6 @@ class LoggerTests: XCTestCase {
     XCTAssertNil(sonLogger.parent)
   }
 
-  
   func testSettingSonLoggerAsyncStatusBreakLinkWithParent() {
     let parentLogger = Logger(identifier: "parent.logger", level: .Info, appenders: [MemoryAppender()])
     let sonLogger = Logger(parentLogger: parentLogger, identifier: "son.logger")
@@ -579,6 +590,24 @@ class LoggerTests: XCTestCase {
     XCTAssertFalse(parentLogger.asynchronous)
     XCTAssertTrue(sonLogger.asynchronous)
   }
+
+  func testSettingSonLoggerTimeProviderBreakLinkWithParent() {
+    let parentLogger = Logger(identifier: "parent.logger", level: .Info, appenders: [MemoryAppender()])
+    let sonLogger = Logger(parentLogger: parentLogger, identifier: "son.logger")
+    let testDate = (
+      Date(timeIntervalSince1970: 42),
+      Date(timeIntervalSince1970: 13)
+    )
+    parentLogger.timeProvider = { return testDate.0 }
+
+    // Execute
+    sonLogger.timeProvider = { return testDate.1 }
+
+    // Validate
+    XCTAssertNil(sonLogger.parent)
+    XCTAssertEqual(parentLogger.timeProvider(), testDate.0)
+    XCTAssertEqual(sonLogger.timeProvider(), testDate.1)
+  }
 
   func testLoggedTimeIsTakenWhenLogIsRequested() {
     let formatter = try! PatternFormatter(identifier:"testFormatter", pattern: "%d{'format':'%s'}")
@@ -599,7 +628,22 @@ class LoggerTests: XCTestCase {
     }
   }
 
-  
+  func testLoggedProvidedTime() {
+    let formatter = try! PatternFormatter(identifier:"testFormatter", pattern: "%D{'format':'ss.SSS'}")
+    let appender = MemoryAppender()
+    appender.thresholdLevel = .Debug
+    appender.formatter = formatter
+    let logger = Logger(identifier: "test.identifier", level: .Debug, appenders: [appender])
+
+    logger.timeProvider = { Date(timeIntervalSince1970: 42.147) }
+
+    // Execute
+    logger.debug("This is a debug message")
+
+    // Validate
+    XCTAssertEqual(appender.logMessages[0].message, "42.147")
+  }
+
   func testLoggingStringWithPercentAndNoParametersDoesNotCrash() {
     let appender = MemoryAppender()
     appender.thresholdLevel = .Debug