Some redesign to better match protocols and semantics

Author: crspybits

Sources/FileLogging/swift_log_file.swift

@@ -30,16 +30,33 @@ struct FileHandlerOutputStream: TextOutputStream {
     }
 }
 
+public struct FileLogging {
+    let stream: TextOutputStream
+    private var localFile: URL
+    
+    public init(to localFile: URL) throws {
+        self.stream = try FileHandlerOutputStream(localFile: localFile)
+        self.localFile = localFile
+    }
+    
+    public func handler(label: String) -> FileLogHandler {
+        return FileLogHandler(label: label, fileLogger: self)
+    }
+    
+    public static func logger(label: String, localFile url: URL) throws -> Logger {
+        let logging = try FileLogging(to: url)
+        return Logger(label: label, factory: logging.handler)
+    }
+}
+
 // Adapted from https://github.com/apple/swift-log.git
-// Changed from using a struct to using a class because of: error: Partial application of 'mutating' method is not allowed
-// when I try to do: `LoggingSystem.bootstrap(logFileHandler.handler)`
 
 /// `FileLogHandler` is a simple implementation of `LogHandler` for directing
 /// `Logger` output to a local file. Appends log output to this file, even across constructor calls.
-public class FileLogHandler: LogHandler {
+public struct FileLogHandler: LogHandler {
     private let stream: TextOutputStream
     private var label: String
-
+    
     public var logLevel: Logger.Level = .info
 
     private var prettyMetadata: String?
@@ -58,22 +75,16 @@ public class FileLogHandler: LogHandler {
         }
     }
 
-    public static func fileLogger(label: String, localFile url: URL) throws -> Logger {
-        let logFileHandler = try FileLogHandler(label: label, localFile: url)
-        return Logger(label: label, factory: logFileHandler.handler)
+    public init(label: String, fileLogger: FileLogging) {
+        self.label = label
+        self.stream = fileLogger.stream
     }
 
     public init(label: String, localFile url: URL) throws {
         self.label = label
         self.stream = try FileHandlerOutputStream(localFile: url)
     }
 
-    // Necessary because the factory method used in the swift logger doesn't allow a throwing constructor.
-    public func handler(label: String) -> LogHandler {
-        self.label = label
-        return self
-    }
-
     public func log(level: Logger.Level,
                     message: Logger.Message,
                     metadata: Logger.Metadata?,

Tests/swift-log-fileTests/swift_log_fileTests.swift

@@ -13,9 +13,9 @@ final class swift_log_fileTests: XCTestCase {
     func testLogToFileUsingBootstrap() throws {
         let logFileURL = try getDocumentsDirectory().appendingPathComponent(logFileName)
         print("\(logFileURL)")
-        let logFileHandler = try FileLogHandler(label: "Foobar", localFile: logFileURL)
+        let fileLogger = try FileLogging(to: logFileURL)
         // Using `bootstrapInternal` so that running `swift test` won't fail. If using this in production code, just use `bootstrap`.
-        LoggingSystem.bootstrapInternal(logFileHandler.handler)
+        LoggingSystem.bootstrapInternal(fileLogger.handler)
 
         let logger = Logger(label: "Test")
 
@@ -26,9 +26,9 @@ final class swift_log_fileTests: XCTestCase {
     func testLogToFileAppendsAcrossLoggerCalls() throws {
         let logFileURL = try getDocumentsDirectory().appendingPathComponent(logFileName)
         print("\(logFileURL)")
-        let logFileHandler = try FileLogHandler(label: "Foobar", localFile: logFileURL)
+        let fileLogger = try FileLogging(to: logFileURL)
         // Using `bootstrapInternal` so that running `swift test` won't fail. If using this in production code, just use `bootstrap`.
-        LoggingSystem.bootstrapInternal(logFileHandler.handler)
+        LoggingSystem.bootstrapInternal(fileLogger.handler)
         let logger = Logger(label: "Test")
 
         // Not really an error.
@@ -44,14 +44,13 @@ final class swift_log_fileTests: XCTestCase {
     func testLogToFileAppendsAcrossConstructorCalls() throws {
         let logFileURL = try getDocumentsDirectory().appendingPathComponent(logFileName)
         print("\(logFileURL)")
-        
-        let logFileHandler1 = try FileLogHandler(label: "Foobar", localFile: logFileURL)
-        let logger1 = Logger(label: "Test", factory: logFileHandler1.handler)
+        let fileLogger = try FileLogging(to: logFileURL)
+
+        let logger1 = Logger(label: "Test", factory: fileLogger.handler)
         logger1.error("Test Test Test")
         let fileSize1 = try getFileSize(file: logFileURL)
 
-        let logFileHandler2 = try FileLogHandler(label: "Foobar", localFile: logFileURL)
-        let logger2 = Logger(label: "Test", factory: logFileHandler2.handler)
+        let logger2 = Logger(label: "Test", factory: fileLogger.handler)
         logger2.error("Test Test Test")
         let fileSize2 = try getFileSize(file: logFileURL)
 
@@ -61,31 +60,28 @@ final class swift_log_fileTests: XCTestCase {
     // Adapted from https://nshipster.com/swift-log/
     func testLogToBothFileAndConsole() throws {
         let logFileURL = try getDocumentsDirectory().appendingPathComponent(logFileName)
+        let fileLogger = try FileLogging(to: logFileURL)
 
         LoggingSystem.bootstrap { label in
-            var handlers = [LogHandler]()
-            
-            // I would prefer if the `bootstrap` does a rethrow.
-            if let logFileHandler = try? FileLogHandler(label: label, localFile: logFileURL) {
-                handlers += [logFileHandler]
-            }
-            
-            handlers += [StreamLogHandler.standardOutput(label: label)]
+            let handlers:[LogHandler] = [
+                FileLogHandler(label: label, fileLogger: fileLogger),
+                StreamLogHandler.standardOutput(label: label)
+            ]
 
             return MultiplexLogHandler(handlers)
         }
 
         let logger = Logger(label: "Test")
 
-        // Manually check that the output also shows up in the Xcode console.
+        // TODO: Manually check that the output also shows up in the Xcode console.
         logger.error("Test Test Test")
     }
 
     func testLoggingUsingLoggerFactoryConstructor() throws {
         let logFileURL = try getDocumentsDirectory().appendingPathComponent(logFileName)
+        let fileLogger = try FileLogging(to: logFileURL)
 
-        let logFileHandler = try FileLogHandler(label: "Foobar", localFile: logFileURL)
-        let logger = Logger(label: "Test", factory: logFileHandler.handler)
+        let logger = Logger(label: "Test", factory: fileLogger.handler)
 
         logger.error("Test Test Test")
         let fileSize1 = try getFileSize(file: logFileURL)
@@ -98,7 +94,8 @@ final class swift_log_fileTests: XCTestCase {
 
     func testLoggingUsingConvenienceMethod() throws {
         let logFileURL = try getDocumentsDirectory().appendingPathComponent(logFileName)
-        let logger = try FileLogHandler.fileLogger(label: "Foobar", localFile: logFileURL)
+
+        let logger = try FileLogging.logger(label: "Foobar", localFile: logFileURL)
 
         logger.error("Test Test Test")
         let fileSize1 = try getFileSize(file: logFileURL)