add helpers tests

Author: Dmitry Verkhoturov

README.md

@@ -80,7 +80,7 @@ func main() {
 		os.Exit(1)
 	}
 	// collect data using provided functions with provided arguments once a minute
-	go metrics.Scheduler(time.Minute, metrics.GoRuntimeStats, []string{""})
+	go metrics.Scheduler(time.Minute, metrics.GoRuntimeStats, []string{})
 	go metrics.Scheduler(time.Minute, metrics.MeasureRuntime, []string{"uptime"}, time.Now())
 
 	//<...>

helpers.go

@@ -108,3 +108,10 @@ func GoRuntimeStats(prefix []string) {
 	// freed.
 	UpdateGauge(append(prefix, "heap_objects"), int64(s.HeapReleased))
 }
+
+// MeasureRuntime measures time elapsed since invocation
+func MeasureRuntime(key []string, start time.Time) {
+	//convert time.Duration to milliseconds
+	elapsed := int64(time.Since(start) / time.Millisecond)
+	UpdateGauge(key, elapsed)
+}

helpers_test.go

@@ -0,0 +1,42 @@
+package metrics
+
+import (
+	"testing"
+	"time"
+
+	"github.com/rcrowley/go-metrics"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestHelpers(t *testing.T) {
+	_ = Setup(
+		"graphite",
+		"localhost",
+		2003,
+		"",
+		time.Hour, // don't flush metrics until Close call
+	)
+
+	go Scheduler(time.Hour, MeasureRuntime, []string{"uptime"}, time.Time{})
+	GoRuntimeStats([]string{"r"})
+
+	// wait for stats to be dumped
+	Close(true)
+
+	// check GoRuntimeStats
+	assert.Nil(t, emm.registry.Get("runtime.random_metric"), "random metric is not present")
+	assert.NotNil(t, emm.registry.Get("r.runtime.num_goroutines"))
+	assert.NotNil(t, emm.registry.Get("r.runtime.heap_alloc"))
+	assert.NotNil(t, emm.registry.Get("r.runtime.sys"))
+	assert.NotNil(t, emm.registry.Get("r.runtime.pause_total_ns"))
+	assert.NotNil(t, emm.registry.Get("r.runtime.num_gc"))
+	assert.NotNil(t, emm.registry.Get("r.runtime.heap_released"))
+	assert.NotNil(t, emm.registry.Get("r.runtime.heap_objects"))
+
+	// check Scheduler and MeasureRuntime
+	// Scheduler problem cases are not tested
+	assert.Equal(t, (time.Now().Sub(time.Time{}) / time.Millisecond).Nanoseconds(), emm.registry.Get("uptime").(metrics.Gauge).Value())
+
+	// cleanup
+	emm.registry.UnregisterAll()
+}

metrics.go

@@ -199,17 +199,8 @@ func UpdateHistogram(key []string, value int64) {
 	emm.metricsChan <- d
 }
 
-// MeasureRuntime measures time elapsed since invocation
-func MeasureRuntime(key []string, start time.Time) {
-	//convert time.Duration to milliseconds
-	elapsed := int64(time.Since(start) / time.Millisecond)
-	UpdateGauge(key, elapsed)
-}
-
 // Close runs cleanup actions
 func Close(printStats bool) {
-	close(emm.metricsChan)
-
 	if printStats {
 		log.Info(emm.registry.GetAll())
 	}

metrics_test.go

@@ -30,8 +30,6 @@ func TestMetricsStoreGraphite(t *testing.T) {
 	UpdateTimer([]string{"happy_time"}, time.Minute)
 	UpdateTimer([]string{"happy_time"}, time.Second)
 
-	MeasureRuntime([]string{"uptime"}, time.Time{})
-
 	// wait for stats to be dumped
 	Close(true)
 
@@ -41,7 +39,6 @@ func TestMetricsStoreGraphite(t *testing.T) {
 	assert.Equal(t, int64(42), emm.registry.Get("happy_routine.happiness_hit").(metrics.Histogram).Sum())
 	assert.Equal(t, int64(2), emm.registry.Get("happy_time").(metrics.Timer).Count())
 	assert.Equal(t, (time.Minute + time.Second).Nanoseconds(), emm.registry.Get("happy_time").(metrics.Timer).Sum())
-	assert.Equal(t, (time.Now().Sub(time.Time{}) / time.Millisecond).Nanoseconds(), emm.registry.Get("uptime").(metrics.Gauge).Value())
 
 	err = Setup(
 		"graphite",
@@ -51,4 +48,6 @@ func TestMetricsStoreGraphite(t *testing.T) {
 		time.Hour,
 	)
 	assert.Nil(t, err, "second call should do nothing and shouldn't return error")
+	// cleanup
+	emm.registry.UnregisterAll()
 }