graph: imported graph as a subtree

graph/simple/densegraph_test.go

@@ -0,0 +1,140 @@
+// Copyright ©2014 The gonum Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package simple
+
+import (
+	"math"
+	"sort"
+	"testing"
+
+	"github.com/gonum/graph"
+	"github.com/gonum/graph/internal/ordered"
+)
+
+var (
+	_ graph.Graph    = (*UndirectedMatrix)(nil)
+	_ graph.Directed = (*DirectedMatrix)(nil)
+)
+
+func TestBasicDenseImpassable(t *testing.T) {
+	dg := NewUndirectedMatrix(5, math.Inf(1), 0, math.Inf(1))
+	if dg == nil {
+		t.Fatal("Directed graph could not be made")
+	}
+
+	for i := 0; i < 5; i++ {
+		if !dg.Has(Node(i)) {
+			t.Errorf("Node that should exist doesn't: %d", i)
+		}
+
+		if degree := dg.Degree(Node(i)); degree != 0 {
+			t.Errorf("Node in impassable graph has a neighbor. Node: %d Degree: %d", i, degree)
+		}
+	}
+
+	for i := 5; i < 10; i++ {
+		if dg.Has(Node(i)) {
+			t.Errorf("Node exists that shouldn't: %d", i)
+		}
+	}
+}
+
+func TestBasicDensePassable(t *testing.T) {
+	dg := NewUndirectedMatrix(5, 1, 0, math.Inf(1))
+	if dg == nil {
+		t.Fatal("Directed graph could not be made")
+	}
+
+	for i := 0; i < 5; i++ {
+		if !dg.Has(Node(i)) {
+			t.Errorf("Node that should exist doesn't: %d", i)
+		}
+
+		if degree := dg.Degree(Node(i)); degree != 4 {
+			t.Errorf("Node in passable graph missing neighbors. Node: %d Degree: %d", i, degree)
+		}
+	}
+
+	for i := 5; i < 10; i++ {
+		if dg.Has(Node(i)) {
+			t.Errorf("Node exists that shouldn't: %d", i)
+		}
+	}
+}
+
+func TestDirectedDenseAddRemove(t *testing.T) {
+	dg := NewDirectedMatrix(10, math.Inf(1), 0, math.Inf(1))
+	dg.SetEdge(Edge{F: Node(0), T: Node(2), W: 1})
+
+	if neighbors := dg.From(Node(0)); len(neighbors) != 1 || neighbors[0].ID() != 2 ||
+		dg.Edge(Node(0), Node(2)) == nil {
+		t.Errorf("Adding edge didn't create successor")
+	}
+
+	dg.RemoveEdge(Edge{F: Node(0), T: Node(2)})
+
+	if neighbors := dg.From(Node(0)); len(neighbors) != 0 || dg.Edge(Node(0), Node(2)) != nil {
+		t.Errorf("Removing edge didn't properly remove successor")
+	}
+
+	if neighbors := dg.To(Node(2)); len(neighbors) != 0 || dg.Edge(Node(0), Node(2)) != nil {
+		t.Errorf("Removing directed edge wrongly kept predecessor")
+	}
+
+	dg.SetEdge(Edge{F: Node(0), T: Node(2), W: 2})
+	// I figure we've torture tested From/To at this point
+	// so we'll just use the bool functions now
+	if dg.Edge(Node(0), Node(2)) == nil {
+		t.Fatal("Adding directed edge didn't change successor back")
+	}
+	c1, _ := dg.Weight(Node(2), Node(0))
+	c2, _ := dg.Weight(Node(0), Node(2))
+	if c1 == c2 {
+		t.Error("Adding directed edge affected cost in undirected manner")
+	}
+}
+
+func TestUndirectedDenseAddRemove(t *testing.T) {
+	dg := NewUndirectedMatrix(10, math.Inf(1), 0, math.Inf(1))
+	dg.SetEdge(Edge{F: Node(0), T: Node(2)})
+
+	if neighbors := dg.From(Node(0)); len(neighbors) != 1 || neighbors[0].ID() != 2 ||
+		dg.EdgeBetween(Node(0), Node(2)) == nil {
+		t.Errorf("Couldn't add neighbor")
+	}
+
+	if neighbors := dg.From(Node(2)); len(neighbors) != 1 || neighbors[0].ID() != 0 ||
+		dg.EdgeBetween(Node(2), Node(0)) == nil {
+		t.Errorf("Adding an undirected neighbor didn't add it reciprocally")
+	}
+}
+
+func TestDenseLists(t *testing.T) {
+	dg := NewDirectedMatrix(15, 1, 0, math.Inf(1))
+	nodes := dg.Nodes()
+
+	if len(nodes) != 15 {
+		t.Fatalf("Wrong number of nodes")
+	}
+
+	sort.Sort(ordered.ByID(nodes))
+
+	for i, node := range dg.Nodes() {
+		if i != node.ID() {
+			t.Errorf("Node list doesn't return properly id'd nodes")
+		}
+	}
+
+	edges := dg.Edges()
+	if len(edges) != 15*14 {
+		t.Errorf("Improper number of edges for passable dense graph")
+	}
+
+	dg.RemoveEdge(Edge{F: Node(12), T: Node(11)})
+	edges = dg.Edges()
+	if len(edges) != (15*14)-1 {
+		t.Errorf("Removing edge didn't affect edge listing properly")
+	}
+}