github.com/livekit/protocol@v1.16.1-0.20240517185851-47e4c6bba773/utils/graph_test.go (about)

     1  // Copyright 2023 LiveKit, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package utils
    16  
    17  import (
    18  	"testing"
    19  
    20  	"github.com/stretchr/testify/require"
    21  	"golang.org/x/exp/maps"
    22  )
    23  
    24  type testNode struct {
    25  	id string
    26  }
    27  
    28  func (n *testNode) ID() string {
    29  	return n.id
    30  }
    31  
    32  type testEdge int
    33  
    34  func (e testEdge) Length() int64 {
    35  	return int64(e)
    36  }
    37  
    38  func testNodeIDs[K comparable, N GraphNodeProps[K]](path []N) []K {
    39  	var names []K
    40  	for _, p := range path {
    41  		names = append(names, p.ID())
    42  	}
    43  	return names
    44  }
    45  
    46  func TestGraph(t *testing.T) {
    47  	t.Run("graph mutation", func(t *testing.T) {
    48  		g := NewGraph[string, *testNode, testEdge]()
    49  		g.InsertNode(&testNode{"a"})
    50  		g.InsertNode(&testNode{"b"})
    51  		g.InsertNode(&testNode{"c"})
    52  
    53  		require.EqualValues(t, &testNode{"a"}, g.Node("a"))
    54  
    55  		g.InsertEdge("a", "b", 1)
    56  		g.InsertEdge("b", "c", 1)
    57  		g.InsertEdge("c", "a", 1)
    58  
    59  		require.Equal(t, []string{"b"}, maps.Keys(g.OutEdges("a")))
    60  		require.Equal(t, []string{"c"}, maps.Keys(g.InEdges("a")))
    61  
    62  		require.EqualValues(t, 1, g.Edge("a", "b"))
    63  
    64  		g.DeleteEdge("a", "b")
    65  		require.False(t, g.HasEdge("a", "b"))
    66  	})
    67  
    68  	t.Run("topological sort", func(t *testing.T) {
    69  		g := NewGraph[string, *testNode, testEdge]()
    70  		g.InsertNode(&testNode{"a"})
    71  		g.InsertNode(&testNode{"b"})
    72  		g.InsertNode(&testNode{"c"})
    73  		g.InsertNode(&testNode{"d"})
    74  		g.InsertNode(&testNode{"e"})
    75  
    76  		g.InsertEdge("a", "b", 1)
    77  		g.InsertEdge("b", "c", 1)
    78  		g.InsertEdge("c", "d", 1)
    79  		g.InsertEdge("d", "e", 1)
    80  
    81  		require.Equal(t, []string{"a", "b", "c", "d", "e"}, testNodeIDs[string](g.TopologicalSort()))
    82  	})
    83  
    84  	t.Run("shortest path", func(t *testing.T) {
    85  		g := NewGraph[string, *testNode, testEdge]()
    86  		g.InsertNode(&testNode{"a"})
    87  		g.InsertNode(&testNode{"b"})
    88  		g.InsertNode(&testNode{"c"})
    89  		g.InsertNode(&testNode{"d"})
    90  
    91  		g.InsertEdge("a", "b", 1)
    92  		g.InsertEdge("a", "c", 3)
    93  		g.InsertEdge("b", "d", 2)
    94  		g.InsertEdge("c", "d", 1)
    95  
    96  		p, n := g.ShortestPath("a", "d")
    97  		require.Equal(t, []string{"a", "b", "d"}, testNodeIDs[string](p))
    98  		require.EqualValues(t, 3, n)
    99  	})
   100  }