Increased accuracy of log timestamps up to nanoseconds. Removed templates of tests for Linux. Minor readme corrections.

Author: DnV1eX

README.md

@@ -1,9 +1,11 @@
 # GoogleCloudLogging
 
-Event logging for client applications on [Apple platforms](#supported-platforms) with support for offline work and automatic upload to [Google Cloud (GCP)](https://cloud.google.com). The package depends on [SwiftLog](https://github.com/apple/swift-log) - an official logging API for Swift, so it can be easly integrated into the project and combined with other logging backends. Log events are stored locally in the [JSON Lines](http://jsonlines.org) file format and bulk uploaded to GCP using the [Cloud Logging API v2](https://cloud.google.com/logging/docs/reference/v2/rest) at time intervals, upon defined event or explicit request. _And yes, it logs itself! (with recursion protection)_ 🤘
+Event logging for client applications on [Apple platforms](#supported-platforms) with support for offline work and automatic upload to [Google Cloud (GCP)](https://cloud.google.com). The package depends on [SwiftLog](https://github.com/apple/swift-log) - an official logging API for Swift, so it can be easly integrated into the project and combined with other logging backends. Log events are stored locally in the [JSON Lines](http://jsonlines.org) file format and bulk uploaded to GCP using the [Cloud Logging API v2](https://cloud.google.com/logging/docs/reference/v2/rest) at time intervals, upon defined event or explicit request.
+
+> And yes, it logs itself! (with recursion protection) 🤘
 
 ## Rationale
-Google recommended logging solution for client applications is Analytics framework, which is now part of the Firebase SDK. Here is a comparison of that framework and this library in terms of logging:
+Google-recommended logging solution for client applications is the Analytics framework, which is now part of the Firebase SDK. Here is a comparison of their framework and this library in terms of logging:
 Library | FirebaseAnalytics | GoogleCloudLogging
 --- | --- | ---
 Platform | Mobile only. _Even Catalyst is not currently supported._ | All modern Apple's OSs. _It is essential for development of universal SwiftUI apps._
@@ -19,7 +21,9 @@ Logging | Proprietary logging functions and implicit usage tracking. | SwiftLog
 Open your application project in Xcode 11 or later, go to menu `File -> Swift Packages -> Add Package Dependency...` and paste the package repository URL `https://github.com/DnV1eX/GoogleCloudLogging.git`.
 
 ### Create Service Account
-In your web browser open the [Google Cloud Console](https://console.cloud.google.com) and create a new project. In `IAM & Admin -> Service Accounts` create a service account choosing `Logging -> Logs Writer` role. In the last step, create and download private key choosing `JSON` format. You need to include this file in your application bundle, just drag the file into the Xcode project and tick the desired targets in the file inspector.
+In your web browser, open the [Google Cloud Console](https://console.cloud.google.com) and create a new project. In `IAM & Admin -> Service Accounts` create a service account choosing `Logging -> Logs Writer` role. In the last step, create and download private key choosing `JSON` format. You need to include this file in your application bundle.
+
+> Just drag the file into the Xcode project and tick the desired targets in the file inspector.
 
 ### Setup Logging
 1. Import both `SwiftLog` and `GoogleCloudLogging` modules:
@@ -74,7 +78,7 @@ logger.error(/* Logged error message */, metadata: [LogKey.error: "\(error)"])
 > `GoogleCloudLogHandler.globalMetadata` takes precedence over `Logger` metadata which in turn takes precedence over log message metadata in case of key overlapping.
 
 ### Analyze Logs
-In your web browser open the [GCP Operations Logging](https://console.cloud.google.com/logs) and select your project. You will see a list of logs for a given **time range** which can be filtered by **log name** _(logger label)_, **severity** _(log level)_, **text payload** _(message)_, **labels** _(metadata)_ etc. **Resource type** for logs produced by GoogleCloudLogHandler is always _Global_.
+In your web browser, open the [GCP Operations Logging](https://console.cloud.google.com/logs) and select your project. You will see a list of logs for a given **time range** which can be filtered by **log name** _(logger label)_, **severity** _(log level)_, **text payload** _(message)_, **labels** _(metadata)_ etc. **Resource type** for logs produced by GoogleCloudLogHandler is always _Global_.
 
 > You can switch to the new Logs Viewer Preview that introduces new features, such as advanced log queries and histograms.
 

Sources/GoogleCloudLogging/GoogleCloudLogging.swift

@@ -308,7 +308,7 @@ class GoogleCloudLogging {
             request.setValue("application/json", forHTTPHeaderField: "Content-Type")
             do {
                 let encoder = JSONEncoder()
-                encoder.dateEncodingStrategy = .iso8601WithFractionalSeconds
+                encoder.dateEncodingStrategy = .iso8601WithNanoseconds
                 let entries: [Log.Entry] = entries.map {
                     var entry = $0
                     entry.logName = Log.name(projectId: self.serviceAccountCredentials.projectId, logId: $0.logName)
@@ -342,13 +342,25 @@ extension Data {
 
 
 
+extension ISO8601DateFormatter {
+    
+    static func internetDateTimeWithNanosecondsString(from date: Date, timeZone: TimeZone = TimeZone(secondsFromGMT: 0)!) -> String {
+        var string = ISO8601DateFormatter.string(from: date, timeZone: timeZone, formatOptions: .withInternetDateTime)
+        var timeInterval = date.timeIntervalSinceReferenceDate
+        if timeInterval < 0 {
+            timeInterval += (-timeInterval * 2).rounded(.up)
+        }
+        string.insert(contentsOf: "\(timeInterval)".drop { $0 != "." }.prefix(10), at: string.index(string.startIndex, offsetBy: 19))
+        return string
+    }
+}
+
+
 extension JSONEncoder.DateEncodingStrategy {
 
-    static let iso8601WithFractionalSeconds = custom { date, encoder in
-        let dateFormatter = ISO8601DateFormatter()
-        dateFormatter.formatOptions = [.withInternetDateTime, .withFractionalSeconds]
+    static let iso8601WithNanoseconds = custom { date, encoder in
         var container = encoder.singleValueContainer()
-        try container.encode(dateFormatter.string(from: date))
+        try container.encode(ISO8601DateFormatter.internetDateTimeWithNanosecondsString(from: date))
     }
 }
 
@@ -369,7 +381,6 @@ extension CharacterSet {
 }
 
 
-
 extension String {
 
     func safeLogId() -> String {

Tests/GoogleCloudLoggingTests/GoogleCloudLoggingTests.swift

@@ -81,6 +81,16 @@ final class GoogleCloudLoggingTests: XCTestCase {
     }
 
 
+    func testISO8601DateFormatterNanoseconds() {
+        
+        XCTAssertEqual(ISO8601DateFormatter.internetDateTimeWithNanosecondsString(from: Date(timeIntervalSinceReferenceDate: 615695580)), "2020-07-06T02:33:00.0Z")
+        XCTAssertEqual(ISO8601DateFormatter.internetDateTimeWithNanosecondsString(from: Date(timeIntervalSinceReferenceDate: 615695580.235942)), "2020-07-06T02:33:00.235942Z")
+        XCTAssertEqual(ISO8601DateFormatter.internetDateTimeWithNanosecondsString(from: Date(timeIntervalSinceReferenceDate: 615695580.987654321)), "2020-07-06T02:33:00.9876543Z")
+        XCTAssertEqual(ISO8601DateFormatter.internetDateTimeWithNanosecondsString(from: Date(timeIntervalSinceReferenceDate: 0.987654321)), "2001-01-01T00:00:00.987654321Z")
+        XCTAssertEqual(ISO8601DateFormatter.internetDateTimeWithNanosecondsString(from: Date(timeIntervalSinceReferenceDate: -0.9876543211)), "2000-12-31T23:59:59.012345678Z")
+    }
+    
+    
     func testSafeLogId() {
 
         XCTAssertEqual("My_class-1.swift".safeLogId(), "My_class-1.swift")
@@ -97,14 +107,4 @@ final class GoogleCloudLoggingTests: XCTestCase {
         logger.critical("LoggerMessage", metadata: ["MessageMetadataKey": "MessageMetadataValue"])
         Thread.sleep(forTimeInterval: 3)
     }
-    
-    
-    static var allTests = [
-        ("testTokenRequest", testTokenRequest),
-        ("testEntriesWrite", testEntriesWrite),
-        ("testLogHandler", testLogHandler),
-        ("testDictionaryUpdate", testDictionaryUpdate),
-        ("testSafeLogId", testSafeLogId),
-        ("testGoogleCloudLogHandler", testGoogleCloudLogHandler),
-    ]
 }