Add Date as metric type

Sources/Clairvoyant/Metric/MetricType.swift

@@ -1,15 +1,36 @@
 import Foundation
 
 public enum MetricType: RawRepresentable {
+
+    /// A Swift `Int` type
     case integer
+
+    /// A Swift `Double` type
     case double
+
+    /// A Swift `Bool` type
     case boolean
+
+    /// A Swift `String` type
     case string
+
+    /// A Swift `Data` type
     case data
+
+    /// A custom type specific to the application
     case customType(named: String)
+
+    /// A Swift `ServerStatus` type
     case serverStatus
+
+    /// A Swift `HTTPStatus` type
     case httpStatus
+
+    /// A `SemanticVersion` type
     case semanticVersion
+
+    /// A Swift `Date` type
+    case date
 
     public var rawValue: String {
         switch self {
@@ -31,6 +52,8 @@ public enum MetricType: RawRepresentable {
             return "HTTP Status"
         case .semanticVersion:
             return "SemanticVersion"
+        case .date:
+            return "Date"
         }
     }
 
@@ -44,6 +67,7 @@ public enum MetricType: RawRepresentable {
         case "Status": self = .serverStatus
         case "HTTP Status": self = .httpStatus
         case "SemanticVersion": self = .semanticVersion
+        case "Date": self = .date
         default:
             self = .customType(named: rawValue)
         }
@@ -70,6 +94,8 @@ public enum MetricType: RawRepresentable {
             return HTTPStatusCode.self
         case .semanticVersion:
             return SemanticVersion.self
+        case .date:
+            return Date.self
         }
     }
 }

Sources/Clairvoyant/Metric/StandardMetricTypes.swift

@@ -24,3 +24,8 @@ extension Data: MetricValue {
 
     public static let valueType: MetricType = .data
 }
+
+extension Date: MetricValue {
+
+    public static let valueType: MetricType = .date
+}