Add tests for counters

report/counters_internal_test.go

@@ -0,0 +1,97 @@
+package report
+
+import (
+	"testing"
+
+	"github.com/weaveworks/scope/test"
+	"github.com/weaveworks/scope/test/reflect"
+)
+
+func TestCountersAdd(t *testing.T) {
+	want := EmptyCounters.
+		Add("foo", 3)
+	have := EmptyCounters.
+		Add("foo", 1).
+		Add("foo", 2)
+	if !reflect.DeepEqual(want, have) {
+		t.Errorf(test.Diff(want, have))
+	}
+	if v, ok := have.Lookup("foo"); !ok || v != 3 {
+		t.Errorf("foo != 3")
+	}
+	if v, ok := have.Lookup("bar"); ok || v != 0 {
+		t.Errorf("bar != nil")
+	}
+}
+
+func TestCountersMerge(t *testing.T) {
+	for name, c := range map[string]struct {
+		a, b, want Counters
+	}{
+		"Empty a": {
+			a: EmptyCounters,
+			b: EmptyCounters.
+				Add("foo", 1),
+			want: EmptyCounters.
+				Add("foo", 1),
+		},
+		"Empty b": {
+			a: EmptyCounters.
+				Add("foo", 1),
+			b: EmptyCounters,
+			want: EmptyCounters.
+				Add("foo", 1),
+		},
+		"Disparate keys": {
+			a: EmptyCounters.
+				Add("foo", 1),
+			b: EmptyCounters.
+				Add("bar", 2),
+			want: EmptyCounters.
+				Add("foo", 1).
+				Add("bar", 2),
+		},
+		"Key merge": {
+			a: EmptyCounters.
+				Add("foo", 1),
+			b: EmptyCounters.
+				Add("foo", 2),
+			want: EmptyCounters.
+				Add("foo", 3),
+		},
+	} {
+		if have := c.a.Merge(c.b); !reflect.DeepEqual(c.want, have) {
+			t.Errorf("%s:\n%s", name, test.Diff(c.want, have))
+		}
+	}
+}
+
+func TestCountersEncoding(t *testing.T) {
+	want := EmptyCounters.
+		Add("foo", 1).
+		Add("bar", 2)
+
+	{
+		gobs, err := want.GobEncode()
+		if err != nil {
+			t.Fatal(err)
+		}
+		have := EmptyCounters
+		have.GobDecode(gobs)
+		if !reflect.DeepEqual(want, have) {
+			t.Error(test.Diff(want, have))
+		}
+	}
+
+	{
+		json, err := want.MarshalJSON()
+		if err != nil {
+			t.Fatal(err)
+		}
+		have := EmptyCounters
+		have.UnmarshalJSON(json)
+		if !reflect.DeepEqual(want, have) {
+			t.Error(test.Diff(want, have))
+		}
+	}
+}