Added a bunch of tests for metrics

metrics_test.go

@@ -0,0 +1,51 @@
+package msgbus
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMetrics(t *testing.T) {
+	assert := assert.New(t)
+
+	m := NewMetrics("test")
+	m.NewCounter("foo", "counter", "help")
+	m.NewCounterFunc("foo", "counter_func", "help", func() float64 { return 1.0 })
+	m.NewGauge("foo", "gauge", "help")
+	m.NewGaugeFunc("foo", "gauge_func", "help", func() float64 { return 1.0 })
+	m.NewGaugeVec("foo", "gauge_vec", "help", []string{"test"})
+
+	m.Counter("foo", "counter").Inc()
+	m.Gauge("foo", "gauge").Add(1)
+	m.GaugeVec("foo", "gauge_vec").WithLabelValues("test").Add(1)
+
+	w := httptest.NewRecorder()
+	r, _ := http.NewRequest("GET", "/", nil)
+
+	m.Handler().ServeHTTP(w, r)
+	assert.Equal(w.Code, http.StatusOK)
+
+	assert.Regexp(
+		`
+# HELP test_foo_counter help
+# TYPE test_foo_counter counter
+test_foo_counter 1
+# HELP test_foo_counter_func help
+# TYPE test_foo_counter_func counter
+test_foo_counter_func 1
+# HELP test_foo_gauge help
+# TYPE test_foo_gauge gauge
+test_foo_gauge 1
+# HELP test_foo_gauge_func help
+# TYPE test_foo_gauge_func gauge
+test_foo_gauge_func 1
+# HELP test_foo_gauge_vec help
+# TYPE test_foo_gauge_vec gauge
+test_foo_gauge_vec{test="test"} 1
+`,
+		w.Body.String(),
+	)
+}