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// 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_test
import (
"math"
"testing"
"golang.org/x/exp/rand"
"gonum.org/v1/gonum/graph"
"gonum.org/v1/gonum/graph/internal/set"
"gonum.org/v1/gonum/graph/simple"
"gonum.org/v1/gonum/graph/testgraph"
)
func directedBuilder(nodes []graph.Node, edges []testgraph.WeightedLine, _, _ float64) (g graph.Graph, n []graph.Node, e []testgraph.Edge, s, a float64, ok bool) {
seen := set.NewNodes()
dg := simple.NewDirectedGraph()
for _, n := range nodes {
seen.Add(n)
dg.AddNode(n)
}
for _, edge := range edges {
if edge.From().ID() == edge.To().ID() {
continue
}
f := dg.Node(edge.From().ID())
if f == nil {
f = edge.From()
}
t := dg.Node(edge.To().ID())
if t == nil {
t = edge.To()
}
ce := simple.Edge{F: f, T: t}
seen.Add(ce.F)
seen.Add(ce.T)
e = append(e, ce)
dg.SetEdge(ce)
}
if len(e) == 0 && len(edges) != 0 {
return nil, nil, nil, math.NaN(), math.NaN(), false
}
if len(seen) != 0 {
n = make([]graph.Node, 0, len(seen))
}
for _, sn := range seen {
n = append(n, sn)
}
return dg, n, e, math.NaN(), math.NaN(), true
}
func TestDirected(t *testing.T) {
t.Run("EdgeExistence", func(t *testing.T) {
testgraph.EdgeExistence(t, directedBuilder, reversesEdges)
})
t.Run("NodeExistence", func(t *testing.T) {
testgraph.NodeExistence(t, directedBuilder)
})
t.Run("ReturnAdjacentNodes", func(t *testing.T) {
testgraph.ReturnAdjacentNodes(t, directedBuilder, usesEmpty, reversesEdges)
})
t.Run("ReturnAllEdges", func(t *testing.T) {
testgraph.ReturnAllEdges(t, directedBuilder, usesEmpty)
})
t.Run("ReturnAllNodes", func(t *testing.T) {
testgraph.ReturnAllNodes(t, directedBuilder, usesEmpty)
})
t.Run("ReturnEdgeSlice", func(t *testing.T) {
testgraph.ReturnEdgeSlice(t, directedBuilder, usesEmpty)
})
t.Run("ReturnNodeSlice", func(t *testing.T) {
testgraph.ReturnNodeSlice(t, directedBuilder, usesEmpty)
})
t.Run("AddNodes", func(t *testing.T) {
testgraph.AddNodes(t, simple.NewDirectedGraph(), 100)
})
t.Run("AddArbitraryNodes", func(t *testing.T) {
testgraph.AddArbitraryNodes(t,
simple.NewDirectedGraph(),
testgraph.NewRandomNodes(100, 1, func(id int64) graph.Node { return simple.Node(id) }),
)
})
t.Run("RemoveNodes", func(t *testing.T) {
g := simple.NewDirectedGraph()
it := testgraph.NewRandomNodes(100, 1, func(id int64) graph.Node { return simple.Node(id) })
for it.Next() {
g.AddNode(it.Node())
}
it.Reset()
rnd := rand.New(rand.NewSource(1))
for it.Next() {
u := it.Node()
d := rnd.Intn(5)
vit := g.Nodes()
for d >= 0 && vit.Next() {
v := vit.Node()
if v.ID() == u.ID() {
continue
}
d--
g.SetEdge(g.NewEdge(u, v))
}
}
testgraph.RemoveNodes(t, g)
})
t.Run("AddEdges", func(t *testing.T) {
testgraph.AddEdges(t, 100,
simple.NewDirectedGraph(),
func(id int64) graph.Node { return simple.Node(id) },
false, // Cannot set self-loops.
true, // Can update nodes.
)
})
t.Run("NoLoopAddEdges", func(t *testing.T) {
testgraph.NoLoopAddEdges(t, 100,
simple.NewDirectedGraph(),
func(id int64) graph.Node { return simple.Node(id) },
)
})
t.Run("RemoveEdges", func(t *testing.T) {
g := simple.NewDirectedGraph()
it := testgraph.NewRandomNodes(100, 1, func(id int64) graph.Node { return simple.Node(id) })
for it.Next() {
g.AddNode(it.Node())
}
it.Reset()
rnd := rand.New(rand.NewSource(1))
for it.Next() {
u := it.Node()
d := rnd.Intn(5)
vit := g.Nodes()
for d >= 0 && vit.Next() {
v := vit.Node()
if v.ID() == u.ID() {
continue
}
d--
g.SetEdge(g.NewEdge(u, v))
}
}
testgraph.RemoveEdges(t, g, g.Edges())
})
}
// Tests Issue #27
func TestEdgeOvercounting(t *testing.T) {
g := generateDummyGraph()
if neigh := graph.NodesOf(g.From(int64(2))); len(neigh) != 2 {
t.Errorf("Node 2 has incorrect number of neighbors got neighbors %v (count %d), expected 2 neighbors {0,1}", neigh, len(neigh))
}
}
func generateDummyGraph() *simple.DirectedGraph {
nodes := [4]struct{ srcID, targetID int }{
{2, 1},
{1, 0},
{2, 0},
{0, 2},
}
g := simple.NewDirectedGraph()
for _, n := range nodes {
g.SetEdge(simple.Edge{F: simple.Node(n.srcID), T: simple.Node(n.targetID)})
}
return g
}
// Test for issue #123 https://github.com/gonum/graph/issues/123
func TestIssue123DirectedGraph(t *testing.T) {
defer func() {
if r := recover(); r != nil {
t.Errorf("unexpected panic: %v", r)
}
}()
g := simple.NewDirectedGraph()
n0 := g.NewNode()
g.AddNode(n0)
n1 := g.NewNode()
g.AddNode(n1)
g.RemoveNode(n0.ID())
n2 := g.NewNode()
g.AddNode(n2)
}