Fixup error in Counter/Gauge

Author: MrLotU

Sources/Prometheus/MetricTypes/Counter.swift

@@ -6,11 +6,14 @@ public class Counter<NumType: Numeric, Labels: MetricLabels>: Metric, Prometheus
 
     internal var value: NumType
 
+    private var initialValue: NumType
+
     internal var metrics: [Labels: NumType] = [:]
 
     internal init(_ name: String, _ help: String? = nil, _ initialValue: NumType = 0, _ p: Prometheus) {
         self.name = name
         self.help = help
+        self.initialValue = initialValue
         self.value = initialValue
         self.prometheus = p
     }
@@ -36,7 +39,7 @@ public class Counter<NumType: Numeric, Labels: MetricLabels>: Metric, Prometheus
     @discardableResult
     public func inc(_ amount: NumType = 1, _ labels: Labels? = nil) -> NumType {
         if let labels = labels {
-            var val = self.metrics[labels] ?? 0
+            var val = self.metrics[labels] ?? initialValue
             val += amount
             self.metrics[labels] = val
             return val
@@ -48,7 +51,7 @@ public class Counter<NumType: Numeric, Labels: MetricLabels>: Metric, Prometheus
 
     public func get(_ labels: Labels? = nil) -> NumType {
         if let labels = labels {
-            return self.metrics[labels] ?? 0
+            return self.metrics[labels] ?? initialValue
         } else {
             return self.value
         }

Sources/Prometheus/MetricTypes/Gauge.swift

@@ -5,12 +5,15 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
     public let help: String?
 
     private var value: NumType
+
+    private var initialValue: NumType
 
     private var metrics: [Labels: NumType] = [:]
 
     internal init(_ name: String, _ help: String? = nil, _ initialValue: NumType = 0, _ p: Prometheus) {
         self.name = name
         self.help = help
+        self.initialValue = initialValue
         self.value = initialValue
         self.prometheus = p
     }
@@ -47,7 +50,7 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
     @discardableResult
     public func inc(_ amount: NumType, _ labels: Labels? = nil) -> NumType {
         if let labels = labels {
-            var val = self.metrics[labels] ?? 0
+            var val = self.metrics[labels] ?? initialValue
             val += amount
             self.metrics[labels] = val
             return val
@@ -65,7 +68,7 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
     @discardableResult
     public func dec(_ amount: NumType, _ labels: Labels? = nil) -> NumType {
         if let labels = labels {
-            var val = self.metrics[labels] ?? 0
+            var val = self.metrics[labels] ?? initialValue
             val -= amount
             self.metrics[labels] = val
             return val
@@ -82,7 +85,7 @@ public class Gauge<NumType: Numeric, Labels: MetricLabels>: Metric, PrometheusHa
 
     public func get(_ labels: Labels? = nil) -> NumType {
         if let labels = labels {
-            return self.metrics[labels] ?? 0
+            return self.metrics[labels] ?? initialValue
         } else {
             return self.value
         }

Sources/PrometheusExample/main.swift

@@ -7,13 +7,17 @@ struct MyCodable: MetricLabels {
 let codable1 = MyCodable(thing: "Thing1")
 let codable2 = MyCodable(thing: "Thing2")
 
-//let counter = Prometheus.shared.createCounter(forType: Int.self, named: "my_counter", helpText: "Just a counter", initialValue: 12)
-//
-//counter.inc(5)
-//
-//let gauge = Prometheus.shared.createGauge(forType: Int.self, named: "my_gauge", helpText: "Just a gauge", initialValue: 0)
-//
-//gauge.set(123)
+let counter = Prometheus.shared.createCounter(forType: Int.self, named: "my_counter", helpText: "Just a counter", initialValue: 12, withLabelType: MyCodable.self)
+
+counter.inc(5)
+counter.inc(Int.random(in: 0...100), codable2)
+counter.inc(Int.random(in: 0...100), codable1)
+
+let gauge = Prometheus.shared.createGauge(forType: Int.self, named: "my_gauge", helpText: "Just a gauge", initialValue: 12, withLabelType: MyCodable.self)
+
+gauge.inc(100)
+gauge.inc(Int.random(in: 0...100), codable2)
+gauge.inc(Int.random(in: 0...100), codable1)
 
 struct HistogramThing: HistogramLabels {
     var le: String = ""