render: fixes for new merge semantics

render/renderable_node_test.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/weaveworks/scope/render"
 	"github.com/weaveworks/scope/report"
+	"github.com/weaveworks/scope/test"
 )
 
 func TestMergeRenderableNodes(t *testing.T) {
@@ -17,19 +18,45 @@ func TestMergeRenderableNodes(t *testing.T) {
 		"bar": render.RenderableNode{ID: "bar"},
 		"baz": render.RenderableNode{ID: "baz"},
 	}
-
-	want := render.RenderableNodes{
+	want := sterilize(render.RenderableNodes{
 		"foo": render.RenderableNode{ID: "foo"},
 		"bar": render.RenderableNode{ID: "bar"},
 		"baz": render.RenderableNode{ID: "baz"},
-	}
+	}, false)
 	nodes1.Merge(nodes2)
-
-	if !reflect.DeepEqual(want, nodes1) {
-		t.Errorf("want %+v, have %+v", want, nodes1)
+	if have := sterilize(nodes1, false); !reflect.DeepEqual(want, have) {
+		t.Error(test.Diff(want, have))
 	}
 }
 
+func sterilize(r render.RenderableNodes, destructive bool) render.RenderableNodes {
+	// Since introducing new map fields to the report.NodeMetadata type, its
+	// zero value is •not valid• -- every time you need one, you need to use
+	// the report.MakeNodeMetadata constructor. (Similarly, but not exactly
+	// the same, is that a zero-value Adjacency is not the same as a created
+	// but empty Adjacency.)
+	//
+	// But we're not doing this in tests. So this function sterilizes invalid
+	// RenderableNodes by fixing all nil Metadata fields. The proper fix
+	// involves lots of annoying changes to instantiation.
+	//
+	// The extra destructive parameter is to support a historical test use
+	// case where we explicitly don't compare node metadata.
+	for id, n := range r {
+		if n.Adjacency == nil {
+			n.Adjacency = report.IDList{}
+		}
+		if destructive || n.NodeMetadata.Metadata == nil {
+			n.NodeMetadata.Metadata = map[string]string{}
+		}
+		if destructive || n.NodeMetadata.Counters == nil {
+			n.NodeMetadata.Counters = map[string]int{}
+		}
+		r[id] = n
+	}
+	return r
+}
+
 func TestMergeRenderableNode(t *testing.T) {
 	node1 := render.RenderableNode{
 		ID:         "foo",
@@ -49,19 +76,19 @@ func TestMergeRenderableNode(t *testing.T) {
 		Adjacency:  report.MakeIDList("a2"),
 		Origins:    report.MakeIDList("o2"),
 	}
-
 	want := render.RenderableNode{
-		ID:         "foo",
-		LabelMajor: "major",
-		LabelMinor: "minor",
-		Rank:       "rank",
-		Pseudo:     false,
-		Adjacency:  report.MakeIDList("a1", "a2"),
-		Origins:    report.MakeIDList("o1", "o2"),
+		ID:           "foo",
+		LabelMajor:   "major",
+		LabelMinor:   "minor",
+		Rank:         "rank",
+		Pseudo:       false,
+		Adjacency:    report.MakeIDList("a1", "a2"),
+		Origins:      report.MakeIDList("o1", "o2"),
+		NodeMetadata: report.MakeNodeMetadata(),
+		EdgeMetadata: report.EdgeMetadata{},
 	}
 	node1.Merge(node2)
-
-	if !reflect.DeepEqual(want, node1) {
-		t.Errorf("want %+v, have %+v", want, node1)
+	if have := node1; !reflect.DeepEqual(want, have) {
+		t.Error(test.Diff(want, have))
 	}
 }