Add basic unit tests for the metrics package.

metrics/metrics_test.go

@@ -0,0 +1,95 @@
+package metrics_test
+
+import (
+ "testing"
+
+ "github.com/creachadair/jrpc2/metrics"
+)
+
+func getCount(m *metrics.M, name string) int64 {
+ c := make(map[string]int64)
+ m.Snapshot(metrics.Snapshot{Counter: c})
+ return c[name]
+}
+
+func getMax(m *metrics.M, name string) int64 {
+ mv := make(map[string]int64)
+ m.Snapshot(metrics.Snapshot{MaxValue: mv})
+ return mv[name]
+}
+
+func getLabel(m *metrics.M, name string) interface{} {
+ vs := make(map[string]interface{})
+ m.Snapshot(metrics.Snapshot{Label: vs})
+ return vs[name]
+}
+
+func TestMetrics(t *testing.T) {
+ m := metrics.New()
+ wantCount := func(name string, want int64) {
+ t.Helper()
+ got := getCount(m, name)
+ if got != want {
+ t.Errorf("Counter %q: got %d, want %d", name, got, want)
+ }
+ }
+ wantMax := func(name string, want int64) {
+ t.Helper()
+ got := getMax(m, name)
+ if got != want {
+ t.Errorf("MaxValue %q: got %d, want %d", name, got, want)
+ }
+ }
+ wantLabel := func(name string, want interface{}) {
+ t.Helper()
+ got := getLabel(m, name)
+ if got != want {
+ t.Errorf("Label %q: got %v, want %v", name, got, want)
+ }
+ }
+
+ wantCount("foo", 0)
+ m.Count("foo", 1)
+ wantCount("foo", 1)
+ m.Count("foo", 4)
+ wantCount("foo", 5)
+ m.Count("foo", -3)
+ wantCount("foo", 2)
+
+ wantMax("max", 0)
+ m.SetMaxValue("max", 10)
+ wantMax("max", 10)
+ m.SetMaxValue("max", 5)
+ wantMax("max", 10)
+ m.SetMaxValue("max", 12)
+ wantMax("max", 12)
+
+ m.CountAndSetMax("bar", 1)
+ wantCount("bar", 1)
+ wantMax("bar", 1)
+ m.CountAndSetMax("bar", 4)
+ wantCount("bar", 5)
+ wantMax("bar", 4)
+ m.CountAndSetMax("bar", -3)
+ wantCount("bar", 2)
+ wantMax("bar", 4)
+ m.CountAndSetMax("bar", 3)
+ wantCount("bar", 5)
+ wantMax("bar", 4)
+
+ wantLabel("hey", nil)
+ m.SetLabel("hey", "you")
+ wantLabel("hey", "you")
+ m.SetLabel("hey", nil)
+ wantLabel("hey", nil)
+
+ wantLabel("quux", nil)
+ m.EditLabel("quux", func(v interface{}) interface{} {
+ return "x"
+ })
+ wantLabel("quux", "x")
+ m.EditLabel("quux", func(v interface{}) interface{} {
+ return v.(string) + "2"
+ })
+ wantLabel("quux", "x2")
+}