render/detailed: When summarising children, add fallback for unlisted topologies

Currently, if a topology does not have any specific info in nodeSummariesByID,
any children of the node that belong to that topology will be silently omitted.

This change adds a default behaviour for such topologies, with no special columns
but at least it is displayed at all.
Unlisted topologies are displayed after all listed ones, in arbitrary order.

Note that completely bogus or other special cases (eg. topology = Pseudo) still will not
be displayed as report.Topology() will fail.

render/detailed/node.go

@@ -246,14 +246,37 @@ func children(r report.Report, n report.Node) []NodeSummaryGroup {
 	})
 
 	nodeSummaryGroups := []NodeSummaryGroup{}
+	// Apply specific group specs in the order they're listed
 	for _, spec := range nodeSummaryGroupSpecs {
 		if len(summaries[spec.topologyID]) > 0 {
 			sort.Sort(nodeSummariesByID(summaries[spec.TopologyID]))
 			group := spec.NodeSummaryGroup
 			group.Nodes = summaries[spec.topologyID]
 			nodeSummaryGroups = append(nodeSummaryGroups, group)
+			delete(summaries, spec.topologyID)
 		}
 	}
+	// As a fallback, in case a topology has no group spec defined, add any remaining at the end
+	for topologyID, nodeSummaries := range summaries {
+		if len(nodeSummaries) == 0 {
+			continue
+		}
+		topology, ok := r.Topology(topologyID)
+		if !ok {
+			continue
+		}
+		apiTopology, ok := primaryAPITopology[topologyID]
+		if !ok {
+			continue
+		}
+		sort.Sort(nodeSummariesByID(nodeSummaries))
+		group := NodeSummaryGroup{
+			ID:      apiTopology,
+			Label:   topology.LabelPlural,
+			Columns: []Column{},
+		}
+		nodeSummaryGroups = append(nodeSummaryGroups, group)
+	}
 
 	return nodeSummaryGroups
 }