Cleanup, fix some small mistakes

Author: MrLotU

Sources/Prometheus/MetricTypes/Counter.swift

@@ -4,6 +4,8 @@ public class Counter<NumType: Numeric, Labels: MetricLabels>: Metric, Prometheus
     public let name: String
     public let help: String?
 
+    public var _type: MetricType = .counter
+    
     internal var value: NumType
 
     private var initialValue: NumType
@@ -21,11 +23,8 @@ public class Counter<NumType: Numeric, Labels: MetricLabels>: Metric, Prometheus
     public func getMetric() -> String {
         var output = [String]()
 
-        if let help = help {
-            output.append("# HELP \(name) \(help)")
-        }
+        output.append(headers)
 
-        output.append("# TYPE \(name) counter")
         output.append("\(name) \(value)")
 
         metrics.forEach { (labels, value) in

Sources/Prometheus/MetricTypes/Gauge.swift

@@ -4,6 +4,8 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
     public let name: String
     public let help: String?
 
+    public var _type: MetricType = .gauge
+    
     private var value: NumType
 
     private var initialValue: NumType
@@ -21,11 +23,8 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
     public func getMetric() -> String {
         var output = [String]()
 
-        if let help = help {
-            output.append("# HELP \(name) \(help)")
-        }
-        
-        output.append("# TYPE \(name) gauge")
+        output.append(headers)
+
         output.append("\(name) \(value)")
 
         metrics.forEach { (labels, value) in

Sources/Prometheus/MetricTypes/Histogram.swift

@@ -17,6 +17,8 @@ public class Histogram<NumType: DoubleRepresentable, Labels: HistogramLabels>: M
     public let name: String
     public let help: String?
 
+    public var _type: MetricType = .histogram
+    
     private var buckets: [Counter<NumType, EmptyCodable>] = []
 
     internal let upperBounds: [Double]
@@ -48,10 +50,7 @@ public class Histogram<NumType: DoubleRepresentable, Labels: HistogramLabels>: M
         var output = [String]()
 
 
-        if let help = help {
-            output.append("# HELP \(name) \(help)")
-        }
-        output.append("# TYPE \(name) histogram")
+        output.append(headers)
 
         var acc: NumType = 0
         for (i, bound) in self.upperBounds.enumerated() {
@@ -85,7 +84,7 @@ public class Histogram<NumType: DoubleRepresentable, Labels: HistogramLabels>: M
     }
 
     public func observe(_ value: NumType, _ labels: Labels? = nil) {
-        if let labels = labels {
+        if let labels = labels, type(of: labels) != type(of: EmptySummaryCodable()) {
             let his = prometheus.getOrCreateHistogram(with: labels, for: self)
             his.observe(value)
             return

Sources/Prometheus/MetricTypes/Metric.swift

@@ -1,10 +1,26 @@
+public enum MetricType: String {
+    case counter, gauge, histogram, summary, info, `enum`
+}
+
 public protocol Metric {
     var name: String { get }
     var help: String? { get }
+    var _type: MetricType { get }
 
     func getMetric() -> String
 }
 
+extension Metric {
+    var headers: String {
+        var output = [String]()
+        if let help = help {
+            output.append("# HELP \(name) \(help)")
+        }
+        output.append("# TYPE \(name) \(_type)")
+        return output.joined(separator: "\n")
+    }
+}
+
 internal protocol PrometheusHandled {
     var prometheus: Prometheus { get }
 }

Sources/Prometheus/MetricTypes/Summary.swift

@@ -16,6 +16,8 @@ public class Summary<NumType: DoubleRepresentable, Labels: SummaryLabels>: Metri
 
     public let name: String
     public let help: String?
+
+    public var _type: MetricType = .summary
 
     internal private(set) var labels: Labels
 
@@ -46,12 +48,9 @@ public class Summary<NumType: DoubleRepresentable, Labels: SummaryLabels>: Metri
 
     public func getMetric() -> String {
         var output = [String]()
-        
-        if let help = help {
-            output.append("# HELP \(name) \(help)")
-        }
-        output.append("# TYPE \(name) summary")
-        
+
+        output.append(headers)
+
         calculateQuantiles(quantiles: quantiles, values: values.map { $0.doubleValue }).sorted { $0.key < $1.key }.forEach { (arg) in
             let (q, v) = arg
             self.labels.quantile = "\(q)"