Added a default jsondecoder

Author: fabianfett

Diff for: Examples/EventSources/Tests/LinuxMain.swift

@@ -1,7 +1 @@
-import XCTest
 
-import EventSourcesTests
-
-var tests = [XCTestCaseEntry]()
-tests += EventSourcesTests.allTests()
-XCTMain(tests)

Diff for: Sources/LambdaRuntime/Events/SNS.swift

@@ -28,13 +28,6 @@ public struct SNS {
     }
   }
 
-  public static var dateFormatter: DateFormatter {
-    let formatter = DateFormatter()
-    formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
-    formatter.timeZone = TimeZone(secondsFromGMT: 0)
-    return formatter
-  }
-  
   public struct Message: Codable {
 
     public enum Attributes: Codable {

Diff for: Sources/LambdaRuntime/Runtime+Codable.swift

@@ -3,18 +3,23 @@ import NIO
 import NIOFoundationCompat
 
 extension LambdaRuntime {
+  
+  public static let awsJSONDecoder = LambdaRuntime.createAWSDecoder()
 
   /// wrapper to use for the register function that wraps the encoding and decoding
   public static func codable<Event: Decodable, Result: Encodable>(
+    decoder: JSONDecoder = LambdaRuntime.awsJSONDecoder,
     _ handler: @escaping (Event, Context) -> EventLoopFuture<Result>)
     -> ((NIO.ByteBuffer, Context) -> EventLoopFuture<ByteBuffer?>)
   {
     return { (inputBytes: NIO.ByteBuffer, ctx: Context) -> EventLoopFuture<ByteBuffer?> in
       let input: Event
       do {
-        input = try JSONDecoder().decode(Event.self, from: inputBytes)
+        input = try decoder.decode(Event.self, from: inputBytes)
       }
       catch {
+        let payload = inputBytes.getString(at: 0, length: inputBytes.readableBytes)
+        ctx.logger.error("Could not decode to type `\(String(describing: Event.self))`: \(error), payload: \(String(describing: payload))")
         return ctx.eventLoop.makeFailedFuture(error)
       }
 
@@ -26,19 +31,35 @@ extension LambdaRuntime {
   }
 
   public static func codable<Event: Decodable>(
+    decoder: JSONDecoder = LambdaRuntime.awsJSONDecoder,
     _ handler: @escaping (Event, Context) -> EventLoopFuture<Void>)
     -> ((NIO.ByteBuffer, Context) -> EventLoopFuture<ByteBuffer?>)
   {
     return { (inputBytes: NIO.ByteBuffer, ctx: Context) -> EventLoopFuture<ByteBuffer?> in
       let input: Event
       do {
-        input = try JSONDecoder().decode(Event.self, from: inputBytes)
+        input = try decoder.decode(Event.self, from: inputBytes)
       }
       catch {
+        let payload = inputBytes.getString(at: 0, length: inputBytes.readableBytes)
+        ctx.logger.error("Could not decode to type `\(String(describing: Event.self))`: \(error), payload: \(String(describing: payload))")
         return ctx.eventLoop.makeFailedFuture(error)
       }
 
       return handler(input, ctx).map { return nil }
     }
   }
+  
+  public static func createAWSDateFormatter() -> DateFormatter {
+    let formatter = DateFormatter()
+    formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
+    formatter.timeZone = TimeZone(secondsFromGMT: 0)
+    return formatter
+  }
+  
+  public static func createAWSDecoder() -> JSONDecoder {
+    let decoder = JSONDecoder()
+    decoder.dateDecodingStrategy = .formatted(self.createAWSDateFormatter())
+    return decoder
+  }
 }

Diff for: Tests/LambdaRuntimeTests/Events/SNSTests.swift

@@ -46,9 +46,7 @@ class SNSTests: XCTestCase {
   func testSimpleEventFromJSON() {
     let data = SNSTests.eventPayload.data(using: .utf8)!
     do {
-      let decoder = JSONDecoder()
-      decoder.dateDecodingStrategy = .formatted(SNS.dateFormatter)
-      let event = try decoder.decode(SNS.Event.self, from: data)
+      let event = try LambdaRuntime.awsJSONDecoder.decode(SNS.Event.self, from: data)
 
       guard let record = event.records.first else {
         XCTFail("Expected to have one record"); return