| /* |
| * Copyright (C) 2014 The Guava Authors |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.google.common.graph; |
| |
| import static com.google.common.graph.GraphConstants.ENDPOINTS_MISMATCH; |
| import static com.google.common.truth.Truth.assertThat; |
| import static com.google.common.truth.TruthJUnit.assume; |
| import static org.junit.Assert.assertTrue; |
| import static org.junit.Assert.fail; |
| |
| import java.util.Set; |
| import org.junit.Test; |
| |
| /** |
| * Abstract base class for testing directed {@link Graph} implementations defined in this package. |
| */ |
| public abstract class AbstractStandardDirectedGraphTest extends AbstractGraphTest { |
| |
| @Override |
| @Test |
| public void nodes_checkReturnedSetMutability() { |
| assume().that(graphIsMutable()).isTrue(); |
| |
| Set<Integer> nodes = graph.nodes(); |
| try { |
| nodes.add(N2); |
| fail(ERROR_MODIFIABLE_SET); |
| } catch (UnsupportedOperationException e) { |
| addNode(N1); |
| assertThat(graph.nodes()).containsExactlyElementsIn(nodes); |
| } |
| } |
| |
| @Override |
| @Test |
| public void adjacentNodes_checkReturnedSetMutability() { |
| assume().that(graphIsMutable()).isTrue(); |
| |
| addNode(N1); |
| Set<Integer> adjacentNodes = graph.adjacentNodes(N1); |
| try { |
| adjacentNodes.add(N2); |
| fail(ERROR_MODIFIABLE_SET); |
| } catch (UnsupportedOperationException e) { |
| putEdge(N1, N2); |
| assertThat(graph.adjacentNodes(N1)).containsExactlyElementsIn(adjacentNodes); |
| } |
| } |
| |
| @Override |
| @Test |
| public void predecessors_checkReturnedSetMutability() { |
| assume().that(graphIsMutable()).isTrue(); |
| |
| addNode(N2); |
| Set<Integer> predecessors = graph.predecessors(N2); |
| try { |
| predecessors.add(N1); |
| fail(ERROR_MODIFIABLE_SET); |
| } catch (UnsupportedOperationException e) { |
| putEdge(N1, N2); |
| assertThat(graph.predecessors(N2)).containsExactlyElementsIn(predecessors); |
| } |
| } |
| |
| @Override |
| @Test |
| public void successors_checkReturnedSetMutability() { |
| assume().that(graphIsMutable()).isTrue(); |
| |
| addNode(N1); |
| Set<Integer> successors = graph.successors(N1); |
| try { |
| successors.add(N2); |
| fail(ERROR_MODIFIABLE_SET); |
| } catch (UnsupportedOperationException e) { |
| putEdge(N1, N2); |
| assertThat(successors).containsExactlyElementsIn(graph.successors(N1)); |
| } |
| } |
| |
| @Override |
| @Test |
| public void incidentEdges_checkReturnedSetMutability() { |
| assume().that(graphIsMutable()).isTrue(); |
| |
| addNode(N1); |
| Set<EndpointPair<Integer>> incidentEdges = graph.incidentEdges(N1); |
| try { |
| incidentEdges.add(EndpointPair.ordered(N1, N2)); |
| fail(ERROR_MODIFIABLE_SET); |
| } catch (UnsupportedOperationException e) { |
| putEdge(N1, N2); |
| assertThat(incidentEdges).containsExactlyElementsIn(graph.incidentEdges(N1)); |
| } |
| } |
| |
| @Test |
| public void predecessors_oneEdge() { |
| putEdge(N1, N2); |
| assertThat(graph.predecessors(N2)).containsExactly(N1); |
| // Edge direction handled correctly |
| assertThat(graph.predecessors(N1)).isEmpty(); |
| } |
| |
| @Test |
| public void successors_oneEdge() { |
| putEdge(N1, N2); |
| assertThat(graph.successors(N1)).containsExactly(N2); |
| // Edge direction handled correctly |
| assertThat(graph.successors(N2)).isEmpty(); |
| } |
| |
| @Test |
| public void incidentEdges_oneEdge() { |
| putEdge(N1, N2); |
| EndpointPair<Integer> expectedEndpoints = EndpointPair.ordered(N1, N2); |
| assertThat(graph.incidentEdges(N1)).containsExactly(expectedEndpoints); |
| assertThat(graph.incidentEdges(N2)).containsExactly(expectedEndpoints); |
| } |
| |
| @Test |
| public void inDegree_oneEdge() { |
| putEdge(N1, N2); |
| assertThat(graph.inDegree(N2)).isEqualTo(1); |
| // Edge direction handled correctly |
| assertThat(graph.inDegree(N1)).isEqualTo(0); |
| } |
| |
| @Test |
| public void outDegree_oneEdge() { |
| putEdge(N1, N2); |
| assertThat(graph.outDegree(N1)).isEqualTo(1); |
| // Edge direction handled correctly |
| assertThat(graph.outDegree(N2)).isEqualTo(0); |
| } |
| |
| @Test |
| public void hasEdgeConnecting_correct() { |
| putEdge(N1, N2); |
| assertThat(graph.hasEdgeConnecting(EndpointPair.ordered(N1, N2))).isTrue(); |
| } |
| |
| @Test |
| public void hasEdgeConnecting_backwards() { |
| putEdge(N1, N2); |
| assertThat(graph.hasEdgeConnecting(EndpointPair.ordered(N2, N1))).isFalse(); |
| } |
| |
| @Test |
| public void hasEdgeConnecting_mismatch() { |
| putEdge(N1, N2); |
| assertThat(graph.hasEdgeConnecting(EndpointPair.unordered(N1, N2))).isFalse(); |
| assertThat(graph.hasEdgeConnecting(EndpointPair.unordered(N2, N1))).isFalse(); |
| } |
| |
| @Test |
| public void adjacentNodes_selfLoop() { |
| assume().that(graph.allowsSelfLoops()).isTrue(); |
| |
| putEdge(N1, N1); |
| putEdge(N1, N2); |
| assertThat(graph.adjacentNodes(N1)).containsExactly(N1, N2); |
| } |
| |
| @Test |
| public void predecessors_selfLoop() { |
| assume().that(graph.allowsSelfLoops()).isTrue(); |
| |
| putEdge(N1, N1); |
| assertThat(graph.predecessors(N1)).containsExactly(N1); |
| putEdge(N4, N1); |
| assertThat(graph.predecessors(N1)).containsExactly(N1, N4); |
| } |
| |
| @Test |
| public void successors_selfLoop() { |
| assume().that(graph.allowsSelfLoops()).isTrue(); |
| |
| putEdge(N1, N1); |
| assertThat(graph.successors(N1)).containsExactly(N1); |
| putEdge(N1, N2); |
| assertThat(graph.successors(N1)).containsExactly(N1, N2); |
| } |
| |
| @Test |
| public void incidentEdges_selfLoop() { |
| assume().that(graph.allowsSelfLoops()).isTrue(); |
| |
| putEdge(N1, N1); |
| assertThat(graph.incidentEdges(N1)).containsExactly(EndpointPair.ordered(N1, N1)); |
| putEdge(N1, N2); |
| assertThat(graph.incidentEdges(N1)) |
| .containsExactly(EndpointPair.ordered(N1, N1), EndpointPair.ordered(N1, N2)); |
| } |
| |
| @Test |
| public void degree_selfLoop() { |
| assume().that(graph.allowsSelfLoops()).isTrue(); |
| |
| putEdge(N1, N1); |
| assertThat(graph.degree(N1)).isEqualTo(2); |
| putEdge(N1, N2); |
| assertThat(graph.degree(N1)).isEqualTo(3); |
| } |
| |
| @Test |
| public void inDegree_selfLoop() { |
| assume().that(graph.allowsSelfLoops()).isTrue(); |
| |
| putEdge(N1, N1); |
| assertThat(graph.inDegree(N1)).isEqualTo(1); |
| putEdge(N4, N1); |
| assertThat(graph.inDegree(N1)).isEqualTo(2); |
| } |
| |
| @Test |
| public void outDegree_selfLoop() { |
| assume().that(graph.allowsSelfLoops()).isTrue(); |
| |
| putEdge(N1, N1); |
| assertThat(graph.outDegree(N1)).isEqualTo(1); |
| putEdge(N1, N2); |
| assertThat(graph.outDegree(N1)).isEqualTo(2); |
| } |
| |
| // Stable order tests |
| |
| // Note: Stable order means that the ordering doesn't change between iterations and versions. |
| // Ideally, the ordering in test should never be updated. |
| @Test |
| public void stableIncidentEdgeOrder_edges_returnsInStableOrder() { |
| assume().that(graph.incidentEdgeOrder().type()).isEqualTo(ElementOrder.Type.STABLE); |
| |
| populateStarShapedGraph(); |
| |
| assertThat(graph.edges()) |
| .containsExactly( |
| EndpointPair.ordered(2, 1), |
| EndpointPair.ordered(1, 4), |
| EndpointPair.ordered(1, 3), |
| EndpointPair.ordered(1, 2), |
| EndpointPair.ordered(3, 1), |
| EndpointPair.ordered(5, 1)) |
| .inOrder(); |
| } |
| |
| @Test |
| public void stableIncidentEdgeOrder_adjacentNodes_returnsInConnectingEdgeInsertionOrder() { |
| assume().that(graph.incidentEdgeOrder().type()).isEqualTo(ElementOrder.Type.STABLE); |
| |
| populateStarShapedGraph(); |
| |
| assertThat(graph.adjacentNodes(1)).containsExactly(2, 4, 3, 5).inOrder(); |
| } |
| |
| @Test |
| public void stableIncidentEdgeOrder_predecessors_returnsInConnectingEdgeInsertionOrder() { |
| assume().that(graph.incidentEdgeOrder().type()).isEqualTo(ElementOrder.Type.STABLE); |
| |
| populateStarShapedGraph(); |
| |
| assertThat(graph.predecessors(1)).containsExactly(2, 5, 3).inOrder(); |
| } |
| |
| @Test |
| public void stableIncidentEdgeOrder_successors_returnsInConnectingEdgeInsertionOrder() { |
| assume().that(graph.incidentEdgeOrder().type()).isEqualTo(ElementOrder.Type.STABLE); |
| |
| populateStarShapedGraph(); |
| |
| assertThat(graph.successors(1)).containsExactly(4, 3, 2).inOrder(); |
| } |
| |
| @Test |
| public void stableIncidentEdgeOrder_incidentEdges_returnsInEdgeInsertionOrder() { |
| assume().that(graph.incidentEdgeOrder().type()).isEqualTo(ElementOrder.Type.STABLE); |
| |
| populateStarShapedGraph(); |
| |
| assertThat(graph.incidentEdges(1)) |
| .containsExactly( |
| EndpointPair.ordered(2, 1), |
| EndpointPair.ordered(1, 4), |
| EndpointPair.ordered(1, 3), |
| EndpointPair.ordered(5, 1), |
| EndpointPair.ordered(1, 2), |
| EndpointPair.ordered(3, 1)) |
| .inOrder(); |
| } |
| |
| @Test |
| public void stableIncidentEdgeOrder_incidentEdges_withSelfLoop_returnsInEdgeInsertionOrder() { |
| assume().that(graph.incidentEdgeOrder().type()).isEqualTo(ElementOrder.Type.STABLE); |
| assume().that(graph.allowsSelfLoops()).isTrue(); |
| |
| putEdge(2, 1); |
| putEdge(1, 1); |
| putEdge(1, 3); |
| putEdge(1, 2); |
| |
| assertThat(graph.incidentEdges(1)) |
| .containsExactly( |
| EndpointPair.ordered(2, 1), |
| EndpointPair.ordered(1, 1), |
| EndpointPair.ordered(1, 3), |
| EndpointPair.ordered(1, 2)) |
| .inOrder(); |
| } |
| |
| /** |
| * Populates the graph with nodes and edges in a star shape with node `1` in the middle. |
| * |
| * <p>Note that the edges are added in a shuffled order to properly test the effect of the |
| * insertion order. |
| */ |
| private void populateStarShapedGraph() { |
| putEdge(2, 1); |
| putEdge(1, 4); |
| putEdge(1, 3); |
| putEdge(5, 1); |
| putEdge(1, 2); |
| putEdge(3, 1); |
| } |
| |
| // Element Mutation |
| |
| @Test |
| public void putEdge_existingNodes() { |
| assume().that(graphIsMutable()).isTrue(); |
| |
| // Adding nodes initially for safety (insulating from possible future |
| // modifications to proxy methods) |
| addNode(N1); |
| addNode(N2); |
| |
| assertThat(graphAsMutableGraph.putEdge(N1, N2)).isTrue(); |
| } |
| |
| @Test |
| public void putEdge_existingEdgeBetweenSameNodes() { |
| assume().that(graphIsMutable()).isTrue(); |
| |
| assertThat(graphAsMutableGraph.putEdge(N1, N2)).isTrue(); |
| assertThat(graphAsMutableGraph.putEdge(N1, N2)).isFalse(); |
| } |
| |
| @Test |
| public void putEdge_orderMismatch() { |
| assume().that(graphIsMutable()).isTrue(); |
| |
| EndpointPair<Integer> endpoints = EndpointPair.unordered(N1, N2); |
| try { |
| graphAsMutableGraph.putEdge(endpoints); |
| fail("Expected IllegalArgumentException: " + ENDPOINTS_MISMATCH); |
| } catch (IllegalArgumentException e) { |
| assertThat(e).hasMessageThat().contains(ENDPOINTS_MISMATCH); |
| } |
| } |
| |
| /** |
| * Tests that the method {@code putEdge} will silently add the missing nodes to the graph, then |
| * add the edge connecting them. We are not using the proxy methods here as we want to test {@code |
| * putEdge} when the end-points are not elements of the graph. |
| */ |
| @Test |
| public void putEdge_nodesNotInGraph() { |
| assume().that(graphIsMutable()).isTrue(); |
| |
| graphAsMutableGraph.addNode(N1); |
| assertTrue(graphAsMutableGraph.putEdge(N1, N5)); |
| assertTrue(graphAsMutableGraph.putEdge(N4, N1)); |
| assertTrue(graphAsMutableGraph.putEdge(N2, N3)); |
| assertThat(graph.nodes()).containsExactly(N1, N5, N4, N2, N3).inOrder(); |
| assertThat(graph.successors(N1)).containsExactly(N5); |
| assertThat(graph.successors(N2)).containsExactly(N3); |
| assertThat(graph.successors(N3)).isEmpty(); |
| assertThat(graph.successors(N4)).containsExactly(N1); |
| assertThat(graph.successors(N5)).isEmpty(); |
| } |
| |
| @Test |
| public void putEdge_doesntAllowSelfLoops() { |
| assume().that(graphIsMutable()).isTrue(); |
| assume().that(graph.allowsSelfLoops()).isFalse(); |
| |
| try { |
| graphAsMutableGraph.putEdge(N1, N1); |
| fail(ERROR_ADDED_SELF_LOOP); |
| } catch (IllegalArgumentException e) { |
| assertThat(e).hasMessageThat().contains(ERROR_SELF_LOOP); |
| } |
| } |
| |
| @Test |
| public void putEdge_allowsSelfLoops() { |
| assume().that(graphIsMutable()).isTrue(); |
| assume().that(graph.allowsSelfLoops()).isTrue(); |
| |
| assertThat(graphAsMutableGraph.putEdge(N1, N1)).isTrue(); |
| assertThat(graph.successors(N1)).containsExactly(N1); |
| assertThat(graph.predecessors(N1)).containsExactly(N1); |
| } |
| |
| @Test |
| public void putEdge_existingSelfLoopEdgeBetweenSameNodes() { |
| assume().that(graphIsMutable()).isTrue(); |
| assume().that(graph.allowsSelfLoops()).isTrue(); |
| |
| graphAsMutableGraph.putEdge(N1, N1); |
| assertThat(graphAsMutableGraph.putEdge(N1, N1)).isFalse(); |
| } |
| |
| @Test |
| public void removeEdge_antiparallelEdges() { |
| assume().that(graphIsMutable()).isTrue(); |
| |
| putEdge(N1, N2); |
| putEdge(N2, N1); |
| |
| assertThat(graphAsMutableGraph.removeEdge(N1, N2)).isTrue(); |
| assertThat(graph.successors(N1)).isEmpty(); |
| assertThat(graph.predecessors(N1)).containsExactly(N2); |
| assertThat(graph.edges()).hasSize(1); |
| |
| assertThat(graphAsMutableGraph.removeEdge(N2, N1)).isTrue(); |
| assertThat(graph.successors(N1)).isEmpty(); |
| assertThat(graph.predecessors(N1)).isEmpty(); |
| assertThat(graph.edges()).isEmpty(); |
| } |
| |
| @Test |
| public void removeEdge_orderMismatch() { |
| assume().that(graphIsMutable()).isTrue(); |
| |
| putEdge(N1, N2); |
| EndpointPair<Integer> endpoints = EndpointPair.unordered(N1, N2); |
| try { |
| graphAsMutableGraph.removeEdge(endpoints); |
| fail("Expected IllegalArgumentException: " + ENDPOINTS_MISMATCH); |
| } catch (IllegalArgumentException e) { |
| assertThat(e).hasMessageThat().contains(ENDPOINTS_MISMATCH); |
| } |
| } |
| |
| @Test |
| public void removeNode_existingNodeWithSelfLoopEdge() { |
| assume().that(graphIsMutable()).isTrue(); |
| assume().that(graph.allowsSelfLoops()).isTrue(); |
| |
| addNode(N1); |
| putEdge(N1, N1); |
| assertThat(graphAsMutableGraph.removeNode(N1)).isTrue(); |
| assertThat(graph.nodes()).isEmpty(); |
| } |
| |
| @Test |
| public void removeEdge_existingSelfLoopEdge() { |
| assume().that(graphIsMutable()).isTrue(); |
| assume().that(graph.allowsSelfLoops()).isTrue(); |
| |
| putEdge(N1, N1); |
| assertThat(graphAsMutableGraph.removeEdge(N1, N1)).isTrue(); |
| assertThat(graph.nodes()).containsExactly(N1); |
| assertThat(graph.successors(N1)).isEmpty(); |
| } |
| } |