scale as unsigned float; tests for values from string or boolean

pkg/config/config.go

@@ -135,7 +135,7 @@ type MetricConfig struct {
 	ValueType          string                    `yaml:"type"`
 	ConstantLabels     map[string]string         `yaml:"const_labels"`
 	StringValueMapping *StringValueMappingConfig `yaml:"string_value_mapping"`
-	MQTTValueScale     uint32                    `yaml:"mqtt_value_scale"`
+	MQTTValueScale     float64                   `yaml:"mqtt_value_scale"`
 }
 
 // StringValueMappingConfig defines the mapping from string to float

pkg/metrics/parser.go

@@ -96,7 +96,7 @@ func (p *Parser) parseMetric(metricPath string, deviceID string, value interface
 	}
 
 	if cfg.MQTTValueScale != 0 {
-		metricValue = metricValue / float64(cfg.MQTTValueScale)
+		metricValue = metricValue / cfg.MQTTValueScale
 	}
 
 	return Metric{

pkg/metrics/parser_test.go

@@ -51,6 +51,32 @@ func TestParser_parseMetric(t *testing.T) {
 				Topic:       "",
 			},
 		},
+		{
+			name: "scaled string value",
+			fields: fields{
+				map[string][]config.MetricConfig{
+					"temperature": []config.MetricConfig{
+						{
+							PrometheusName: "temperature",
+							ValueType:      "gauge",
+							MQTTValueScale: 100,
+						},
+					},
+				},
+			},
+			args: args{
+				metricPath: "temperature",
+				deviceID:   "dht22",
+				value:      "12.6",
+			},
+			want: Metric{
+				Description: prometheus.NewDesc("temperature", "", []string{"sensor", "topic"}, nil),
+				ValueType:   prometheus.GaugeValue,
+				Value:       0.126,
+				IngestTime:  testNow(),
+				Topic:       "",
+			},
+		},
 		{
 			name: "string value failure",
 			fields: fields{
@@ -121,6 +147,32 @@ func TestParser_parseMetric(t *testing.T) {
 				Topic:       "",
 			},
 		},
+		{
+			name: "negative scaled float value",
+			fields: fields{
+				map[string][]config.MetricConfig{
+					"humidity": []config.MetricConfig{
+						{
+							PrometheusName: "humidity",
+							ValueType:      "gauge",
+							MQTTValueScale: -0.5,
+						},
+					},
+				},
+			},
+			args: args{
+				metricPath: "humidity",
+				deviceID:   "dht22",
+				value:      12.6,
+			},
+			want: Metric{
+				Description: prometheus.NewDesc("humidity", "", []string{"sensor", "topic"}, nil),
+				ValueType:   prometheus.GaugeValue,
+				Value:       -25.2,
+				IngestTime:  testNow(),
+				Topic:       "",
+			},
+		},
 		{
 			name: "bool value true",
 			fields: fields{
@@ -146,6 +198,32 @@ func TestParser_parseMetric(t *testing.T) {
 				Topic:       "",
 			},
 		},
+		{
+			name: "scaled bool value",
+			fields: fields{
+				map[string][]config.MetricConfig{
+					"enabled": []config.MetricConfig{
+						{
+							PrometheusName: "enabled",
+							ValueType:      "gauge",
+							MQTTValueScale: 2,
+						},
+					},
+				},
+			},
+			args: args{
+				metricPath: "enabled",
+				deviceID:   "dht22",
+				value:      true,
+			},
+			want: Metric{
+				Description: prometheus.NewDesc("enabled", "", []string{"sensor", "topic"}, nil),
+				ValueType:   prometheus.GaugeValue,
+				Value:       0.5,
+				IngestTime:  testNow(),
+				Topic:       "",
+			},
+		},
 		{
 			name: "bool value false",
 			fields: fields{